A rare virus spread by mosquitoes has killed five people in the US this year. The latest death, announced on 27 August, occurred in New Hampshire and is the state’s first known case of the virus since 2014. Massachusetts, New Jersey, Vermont and Wisconsin have each reported a case as well. The situation has become so concerning that some towns have closed parks after dusk – peak mosquito-biting hours – and restricted outdoor activities and public events.
Monkeypox virus particles (shown in this coloured electron micrograph) can spread through close contact with people and animals.Credit: NIAID/Science Photo Library
When the World Health Organization (WHO) declared a public-health emergency over mpox earlier this month, it was because a concerning form of the virus that causes the disease had spread to multiple African countries where it had never been seen before. Since then, two people travelling to Africa — one from Sweden and one from Thailand — have become infected with that type of virus, called clade 1b, and brought it back to their countries.
Monkeypox virus: dangerous strain gains ability to spread through sex, new data suggest
Although researchers have known about the current outbreak since late last year, the need for answers about it is now more pressing than ever. The Democratic Republic of the Congo (DRC) in Central Africa has spent decades grappling with clade I virus — a lineage to which Ib belongs. But in the past, clade I infections usually arose when a person came into contact with wild animals, and outbreaks would fizzle.
Clade Ib seems different, and is spreading largely through human contact, including through sex. Nearly 18,000 cases of mpox, many of them among children, and at least 600 deaths have been reported this year in the DRC alone.
How does this emergency compare with one declared in 2022, when mpox cases spread across the globe? How is this virus behaving compared with the version that triggered that outbreak, a type called clade II? And will Africa be able to rein this one in? Nature talks with researchers about information they are rushing to gather.
Is clade Ib more deadly than the other virus types?
It’s hard to determine, says Jason Kindrachuk, a virologist at the University of Manitoba in Winnipeg, Canada. He says that the DRC is experiencing two outbreaks simultaneously. The clade I virus, which has been endemic in forested regions of the DRC for decades, circulates in rural regions where people get it from animals. That clade was renamed Ia after the discovery of clade Ib. Animal studies suggest that clade I is deadlier than clade II1 — but Kindrachuk says it’s hard to speculate what that means for humans at this point.
Even when not fatal, mpox can trigger fevers, aches and painful fluid-filled skin lesions.
Growing mpox outbreak prompts WHO to declare global health emergency
Although many reports claim that 10% of clade I infections in humans are fatal, infectious disease specialist Laurens Liesenborghs at the Institute of Tropical Medicine in Antwerp, Belgium, doubts that this figure is accurate. Even the WHO’s latest estimate of a 3.5% fatality rate for people with mpox in the DRC might be high.
There are many reasons fatality estimates might be unreliable, Liesenborghs says. For one, surveillance data captures only the most severe cases; many people who are less ill might not seek care at hospitals or through physicians, so their infections go unreported.
Another factor that can confound fatality rates is a secondary health condition. For example, people living with HIV — who represent a significant proportion of the population in many African countries — die from mpox at twice the rate of people who do not have compromised immune systems, especially if their HIV is untreated2. And the high death rate among children under age 5 could be partly due to malnutrition, which is common among kids in rural parts of the DRC, Liesenborghs says.
Is clade Ib more transmissible than other types?
The clade 1b virus has garnered particular attention because epidemiological data suggest that it transmits more readily between people than previous strains, including through sexual activity, while clade Ia mostly comes from animals. An analysis published ahead of peer review last week to the preprint server medRxiv3 shows that clade Ib’s genome contains genetic mutations that seem to have been induced by the human immune system, suggesting that it has been in humans for some time. Clade Ia genomes have fewer of these mutations.
But Liesenborghs says that the mutations and clades might not be the most important factor in understanding how the monkeypox virus spreads. Although distinguishing Ia from Ib is useful in tracking the disease, he says, severity and transmissibility of disease could be more affected by the region where the virus is circulating and the people there. Clade Ia, for instance, seems to be more common in sparsely populated rural regions where it is less likely to spread far. Clade Ib is cropping up in densely populated areas and spreading more readily.
Jean Nachega, an infectious disease physician at the University of Pittsburgh in Pennsylvania, says that scientists don’t understand many aspects of mpox transmission — they haven’t even determined which animal serves as a reservoir for the virus in the wild, although rodents are able to carry it. “We have to be very humble,” Nachega says.
How effective are vaccines against the clade I virus?
Just as was the case during the COVID-19 pandemic, health experts are looking to vaccines to help curb this mpox outbreak. Although there are no vaccines designed specifically against the monkeypox virus, there are vaccines proven to ward off a related virus — the one that causes smallpox. Two currently exist. Jynneos, made by Bavarian Nordic in Hellerup, Denmark, contains a type of poxvirus that can’t replicate but can trigger an immune response. LC16m8, made by KM Biologics in Kumamoto, Japan, contains a live — but weakened — version of a different poxvirus strain.
Hopes dashed for drug aimed at monkeypox virus spreading in Africa
Still, it’s unclear how effective these smallpox vaccines are against mpox generally. Dimie Ogoina, an infectious disease specialist at Niger Delta University in Wilberforce Island, Nigeria, points out that vaccines have been tested only against clade II virus in European and American populations because these shots were distributed by wealthy nations during the global outbreak that started in 2022. And those recipients were primarily young, healthy men who have sex with men, the population that drove that outbreak. One study in the United States found that one dose of Jynneos was 80% effective at preventing the disease in people at risk while two doses was 82% effective4; the WHO recommends getting both jabs.
People in Africa infected with either the clade Ia or 1b virus — especially children and those with compromised immune systems — might respond differently, although one study in the DRC found that the Jynneos vaccine could generally raise antibodies against mpox in about 1,000 healthcare workers who received it5.
But researchers are trying to fill in some data gaps. A team in the DRC is about to launch a clinical trial of Jynneos in people who have come into close contact with the monkeypox virus — but have not shown symptoms — to see whether it can prevent future infection, or improve outcomes if an infection arises.
Will the vaccines help to rein in the latest outbreak?
Mpox vaccines have so far been largely unavailable in Africa, but several wealthy countries have pledged to donate doses to the DRC and other affected African nations. The United States has offered 50,000 Jynneos doses from its national stockpile, and the European Union has ordered 175,000, with individual member countries pledging additional doses and Bavarian Nordic adding another 40,000. Japan has offered 3.5 million doses of LC16m8 (which requires only one jab instead of two).
Monkeypox in Africa: the science the world ignored
None of them has arrived yet, though, says Espoir Bwenge Malembaka, an epidemiologist at the Catholic University of Bukavu in the DRC. Low- and middle-income nations that rely on vaccine donations cannot receive them until the WHO has determined that the jabs are safe and effective. And so far, the WHO has not given its thumbs up. It is evaluating additional data that it received from vaccine manufacturers, delaying donors’ ability to send the vaccines.
Even when the vaccines arrive, Bwenge Malembaka says, “it’s really a drop in the bucket.” The African Centres for Disease Control and Prevention in Addis Ababa, Ethiopia, estimates that 10 million doses are needed to rein in the outbreak.
Bwenge Malembaka says that the uncertainty over vaccine arrival has made it difficult for the government to form a distribution plan. “I don’t know how one can go about this kind of challenge,” he says. Bwenge Malembaka suspects children are likely to receive doses first, because they are highly vulnerable to clade I, but officials haven’t decided which regions to target. It’s also unclear how the government would prioritize other vulnerable populations such as sex workers, who have been affected by clade Ib. Their profession is criminalized in the DRC, so they might not be able to come forwards for treatment.
Researchers lament that public-health organizations didn’t provide vaccines and other resources as soon as the clade I outbreak was identified, especially given lessons learned from the 2022 global mpox outbreak. “The opportunity was there a couple months ago to cut this transmission chain, but resources weren’t available,” Liesenborghs says. “Now it will be more challenging to tackle this outbreak, and the population at risk is much broader.”
As mpox continues to spread in Central Africa, a promising antiviral drug to treat the infection has failed to improve patients’ symptoms in a trial in the Democratic Republic of the Congo, the epicenter of the outbreak.
In the trial, the drug tecovirimat, also known as TPOXX, did not alleviate the characteristic blisterlike rash seen in people with mpox, formerly known as monkeypox. In an unusual step, the US National Institute of Allergy and Infectious Diseases (NIAID), which sponsored the study, announced the initial findings earlier this month prior to the full results being peer reviewed and published in a scientific journal.
Lori Dodd, branch chief of NIAID’s clinical trials research and statistics branch, tells WIRED that the agency shared the initial results “due to the urgent need for scientific evidence on the use of tecovirimat for the treatment of mpox.” That urgency, she says, was reinforced by the World Health Organization designating the mpox outbreak in Central Africa as a global health emergency on August 14. It’s the second such declaration in two years.
The results come as a disappointment, especially as Central African countries are struggling to contain transmission of mpox. Since the beginning of this year, 13 African countries have recorded a total of 20,720 confirmed or suspected cases of mpox and 582 deaths, according to an August 25 report from the Africa Centres for Disease Control and Prevention.
On Monday, the World Health Organization launched a six-month strategic plan aimed at reining in the outbreak. The plan, which is estimated to cost $135 million, includes boosting surveillance efforts, as well as improving access to testing and vaccines. “The mpox outbreaks in the Democratic Republic of the Congo and neighboring countries can be controlled, and can be stopped,” said Tedros Adhanom Ghebreyesus, WHO Director-General, in a statement.
There are approved vaccines to prevent mpox but no drugs indicated to treat the disease. Tecovirimat was approved by the US Food and Drug Administration in 2018 for the treatment of smallpox, a related virus, and ongoing trials of the drug were launched in 2022 to treat mpox amid a global outbreak of the disease. The drug has also been available in the US for mpox through an expanded access program, which allows a physician to treat a patient with an investigational drug outside of a clinical trial. In the UK and Europe, TPOXX was approved for mpox under exceptional circumstances without comprehensive data on its efficacy.
As part of the trial in the DRC, nearly 600 participants were randomly assigned to receive tecovirimat or a placebo and were admitted to a hospital for at least 14 days, where they were monitored closely. All participants received supportive care, which included nutrition, hydration, and treatment for any secondary infections. While the drug was found to be safe, it was no better at clearing up patients’ lesions than the placebo.
Notably, mortality was lower, and patients’ lesions cleared up faster than anticipated regardless of whether they received tecovirimat or placebo. The study’s 1.7 percent overall mortality among enrollees, regardless of whether they received the drug or not, was much lower than the mpox mortality of 3.6 percent or higher reported among all cases in the DRC.
The Southern house mosquito (Culex quinquefasciatus; artificially coloured) can transmit Oropouche virus to humans, but the main vector is the midge Culicoides paraensis.Credit: Dennis Kunkel Microscopy/Science Photo Library
Once confined to the Amazon region, the mysterious virus that causes the disease called Oropouche fever has been expanding its range since late 2023, spurring international concern. The virus has already caused more than 8,000 human infections in the Americas this year, most in Brazil but also in Peru, Bolivia, Colombia and Cuba.
In July, authorities in Brazil reported the deaths of two adults from the disease — the first since the virus was identified almost 70 years ago. Brazilian officials are also investigating cases of fetal deaths and malformations that might have been caused by the virus, which has now been shown to spread from a pregnant person to their fetus. There are no vaccines or treatments targeting the disease.
Nature spoke with Gonzalo Bello, a public health specialist at the Oswaldo Cruz Institute in Rio de Janeiro, Brazil, who has studied the lineage of the Oropouche virus currently spreading in the Americas.
What is Oropouche?
Oropouche is a virus of the genus Orthobunyavirus. It differs from other better-known vector-borne viruses like dengue, Zika, yellow fever or chikungunya because it is typically transmitted to humans by a midge, Culicoides paraensis, rather than by mosquitoes. But we cannot rule out the possibility that other vectors might be involved. [The virus has been found in other insects, including the mosquito Culex quinquefasciatus.]
For how long has this virus been around?
It was discovered in 1955 in Trinidad and Tobago, in the Caribbean. In 1960, it was first detected in Brazil from a blood sample taken from a sloth. Since the 1960s, it has been identified in outbreaks in humans more or less intermittently in the Amazon region [a vast area that spans nine countries in South America]. That’s why we say it’s a re-emerging virus, because it has been circulating for many decades at least in the Amazon, which is considered an endemic region.
Why are we only hearing about it now? Is this the biggest outbreak we’ve seen?
When it comes to the Amazon region, it is difficult to say whether the current outbreak is larger than in previous decades. For the first time, a molecular surveillance diagnostic system is being implemented, something that didn’t exist in past epidemics.
Climate change will force new animal encounters — and boost viral outbreaks
The geographic extension of the outbreak does represent a change. The number of municipalities and states affected is much higher. Additionally, the virus has spread outside the Amazon region. Again, we don’t know whether this is the first time because there was no surveillance of Oropouche outside the Amazon before.
What also raises concern is the finding of local transmission in Cuba for the first time. and imported cases in Europe and in the United States. As the Culicoides paraensis midge is found throughout the Americas, from the United States to Argentina, whenever there are infected people and there are vectors, there may be local transmission events. So, any infected individual can generate a local epidemic, that’s the main concern.
What are the symptoms?
The symptoms are similar to [those of] other arboviruses such as dengue: fever, headache, muscle or joint pain, pain behind the eyes, vomiting and nausea. So, it’s very difficult to diagnose an Oropouche infection only from symptoms, you really need to have a molecular laboratory diagnosis. A few cases may evolve into more severe forms, with neurological or hemorrhagic manifestations, but most cases are mild and resolve after seven or eight days.
Is the virus becoming more dangerous? Can it cause microcephaly, an abnormally small head, in babies?
For the first time, the presence of antibodies against Oropouche, indicative of a recent infection, was found in newborns with microcephaly. This suggests an association, but because of the study’s limitations, it wasn’t possible to establish a causal relationship between infection during intrauterine life and the neurological malformations.
Massive mosquito factory in Brazil aims to halt dengue
But it was possible to establish proof of mother-to-child transmission in cases of fetal and newborn death. In one case, a pregnant woman had symptoms of Oropouche and, weeks later, fetal death was confirmed. The Oropouche genome was detected in several organs of the fetus. In another recent case, a pregnant woman tested positive for Oropouche. The baby was born but died days later. Post-mortem examination identified the virus genome in various tissues, including the brain.
There were also two deaths of previously healthy young women who had symptoms similar to severe dengue. They were not pregnant. These were the first cases in the literature classified as deaths associated with Oropouche infection.
It is not yet possible to establish how frequently these fatal cases would be happening, either in adults or fetuses. So far, there is no evidence that the symptoms have changed compared with previous outbreaks.
Amidst a summer surge of Covid-19 infections, the US Food and Drug Administration just approved updated mRNA vaccines that more closely target the currently circulating variants of the coronavirus.
The updated vaccines, from Moderna and Pfizer/BioNTech, target a variant of Omicron called KP.2, one of the several so-called “FLiRT variants” that collectively are responsible for the current Covid wave. The new vaccines will likely take a few weeks to reach pharmacies and doctors offices.
“Given waning immunity of the population from previous exposure to the virus and from prior vaccination, we strongly encourage those who are eligible to consider receiving an updated Covid-19 vaccine,” said Peter Marks, director of the FDA’s Center for Biologics Evaluation and Research, in a statement on Thursday.
The new 2024-2025 formula is meant to boost protection against hospitalization and death due to Covid. In 2023, more than 916,300 people were hospitalized due to Covid-19 and more than 75,500 people died from the virus in the US alone. Vaccination can also protect against long Covid, a chronic condition that lasts at least three months after an infection.
The US Centers for Disease Control and Prevention recommends the new vaccine for everyone 6 months of age and older, whether or not they have ever previously gotten a Covid-19 vaccine.
Like the influenza virus, SARS-CoV-2 is constantly changing. And similar to how flu vaccines are updated every year to adapt to the virus’s changing structure, the Covid vaccines are also being updated. Elizabeth Hudson, regional chief of infectious disease at Kaiser Permanente Southern California says SARS-CoV-2 is changing faster than the flu virus, making it tricky to predict which variants will be dominant by the time the vaccine comes out. “It’s spinning through variants more quickly than what we’re seeing with flu,” she says.
The FDA greenlight comes after an advisory committee in June unanimously recommended that manufacturers develop updated Covid vaccines for this fall. Based on the evidence at the time, FDA advisers initially recommended that the new vaccines target a lineage called JN.1, an Omicron offshoot. But the agency updated its guidance, asking vaccine makers to instead target the KP.2 strain, a descendant of the JN.1 variant, to more closely match circulating variants.
The last version of the Covid vaccine was greenlit by the FDA on September 11, 2023. That formula targeted the XBB.1.5 variant, the predominant one circulating in the US during the first half of 2023. The virus has mutated substantially since then, and the currently circulating FLiRT variants are thought to be more transmissible and evade the immune system more effectively than prior versions of the virus.
“Most of the time, we recommend getting both the Covid and the flu vaccines more towards late September, October, to try to carry people through the winter months,” says Rosha McCoy, a pediatrician and senior director of healthcare affairs at the Association of American Medical Colleges. “Certainly, if somebody is high risk, or is going to be in a high risk situation, they may want to get it sooner.”
Typically, the largest surge of respiratory viruses occurs in the winter. But Covid tends to peak in both winter and summer, and the current summertime surge is likely due to the emergence of new variants and waning protection of the previous vaccine.
“Any natural immunity or vaccine immunity from 2023 has reached a nadir,” Hudson says. “This is sort of a perfect storm for a more infectious form of Covid.”
For millennia, humanity has obsessed about halting ageing and, ultimately, preventing death. Yet while advances in medicine and public-health have seen human life-expectancy more than double, our maximum lifespan stubbornly remains around 120 years.
On the latest episode of Nature hits the books, Nobel laureate Venki Ramakrishnan joins us to discuss what scientists have learnt about the molecular processes underlying ageing, whether they can be prevented, and why the quest for longevity also needs to consider the health-related issues associated with old age.
Forever young: what science can and can’t tell us about cheating ageing
Why We Die: The New Science of Ageing and the Quest for Immortality Venki Ramakrishnan Hodder (2024)
Music supplied by Airae/Epidemic Sound/Getty images.
This story is part of special report on science and extreme heat. Read about the scientists studying how scorching temperatures affect the body, how climate change is intensifying health problems and the record-breaking warming at the Great Barrier Reef.
George Luber was warming up to compete in his third tennis match on a hot summer’s day in Connecticut. Suddenly, in a daze, he started to drift in circles around the end of the court. Then he began vomiting. The next thing Luber remembers is waking up in hospital, where he was treated for heat stroke for three days. He was a healthy 12-year-old, and it was 1982.
What is the hottest temperature humans can survive? These labs are redefining the limit
Luber, now a medical anthropologist at Emory University in Atlanta, Georgia, knows that those most at risk from extreme heat include older people, pregnant women and outdoor workers. But his experience shows that hot weather can affect you even “if you’re a healthy young person with no pre-existing conditions”.
Extreme heat is a serious public-health threat: on average, it kills more people in the United States than any other weather event, including hurricanes, floods and extreme cold. The effects of scorching temperatures are exacerbated in cities, where buildings and roads soak up warmth. As Earth’s warming climate intensifies the problem, scientists are investigating evidence-based measures to make cities safer during hot periods. Researchers say that although progress has been made to address the threat, there are still obstacles to cities’ efforts to track mortality rates and implement solutions.
Hotspots and habits
Luber has seen first hand the devastating effect that scorching temperatures can have in cities. In 2003, when he was studying extreme heat at the US Centers for Disease Control and Prevention in Atlanta, more than 70,000 people died in one of Europe’s worst heatwaves. Luber flew to Paris, which was particularly hard hit, to study the event. “The morgues were overflowing,” he says. “They had to get refrigerated trucks to put the bodies in and it was a massive panic.”
Extreme heat harms health — what is the human body’s limit?
Cities are hotspots because of the urban ‘heat island’ effect: buildings, roads and other impervious surfaces absorb the Sun’s heat during the day and radiate warmth into the night, raising air temperatures. High night-time temperatures amplify the problem, Luber says, because the body can only withstand searing heat for short periods. Illnesses related to heat can develop slowly, when people cannot find respite for several days. That’s why the highest mortality rates occur a few days into a heatwave, he says.
The stagnant air that accompanies a heatwave also magnifies air pollution, because ground-level ozone and particulate matter become more concentrated when the air does not circulate. Cities with high levels of air pollution, such as Los Angeles in California and Beijing face dismal air quality when the heat rises. This can compound the effects of heat on health.
Cooling stations with water can help people to lower their core body temperatures when conditions are scorching.Credit: Vishal Bhatnagar/NurPhoto via Getty
As the climate changes, places already burdened with extreme heat are now projected to have more dangerous heat days per year. But heatwaves will be deadliest in places that have historically not suffered from extreme high temperatures, Luber says, “because dealing with the heat is not only a physical thing, it’s a cultural and behavioural thing”.
Local solutions
Small shifts in behaviour alone will not protect people from heat. Eleni Myrivili is global chief heat officer at the United Nations Human Settlements Programme and is based in Athens, where summer temperatures can exceed 40°C. A 16-day heatwave in the city this July was “absolutely unbearable”, Myrivili says. “It’s almost like the whole city is in a state of depression. Nobody wants to do anything, everybody’s feeling kind of nauseated and kind of weird.”
Cities should approach the problem by raising awareness, providing resources and redesigning the built environment, Myrivili says.
Vulnerable populations, including people living in poverty, need to know that they are at risk and where they can access services when temperatures rise. Myrivili suggests that cities set up cooling stations — with air conditioners, fans and water — in areas that have the least relief from the heat, so that people can lower their core body temperatures for a recommended 2–3 hours per day. She also says that insurance should be available to people who work outdoors to cover lost wages when weather conditions make working unsafe.
Such a scheme was trialled in India in May, which has been experiencing periods of deadly heat. A non-profit organization called Climate Resilience for All partnered with the insurance company Swiss Re to help cover the lost wages of 46,000 women when temperatures became dangerous.
Dileep Mavalankar, former director of the Indian Institute of Public Health in Gandhinagar, helped to create India’s first ‘heat action plan’ in the city of Ahmedabad in 2013 after a 2010 heatwave killed 1,344 people there. The plan includes making public announcements in the days before high temperatures, providing cooling stations and preparing the emergency services for the event.
Cities must protect people from extreme heat
Mavalankar says that although these measures are probably helping, he cannot assess by how much, because death-registration data are not systematically made public.
Even in places where national data are available, gaps in local information can make understanding and addressing the problem difficult. Greece, for instance, does not collect hospital data linking mortality and morbidity to extreme heat. Instead, after a heatwave, the national death toll is estimated by comparing how many people normally die with how many people died during the hot period. Myrivili doesn’t know how many died during the latest heatwave in Athens, or which areas were hit the hardest.
Green cities
Redesigning cities to have more green, natural features that provide shade and release moisture is the next step. Growing trees and increasing access to cool outdoor spaces “can make a difference between life and death”, Myrivili says. But “even though we know, generally, what the solutions are, they need to be custom made and adapted to the specifics of very localized challenges”.
A study published on 12 August in Nature Medicine1 shows that some strategies might be working. Elisa Gallo, an epidemiologist at the Barcelona Institute for Global Health in Spain, and her colleagues estimated that 47,690 people in Europe died from heat in 2023. Using statistical modelling, the team calculated that if the record-breaking heat of 2023 had occurred at the start of the century, the death toll would have been 80% higher than if it had happened between 2015 and 2019.
The city of Fort Collins in Colorado is working with scientists to introduce effective cooling features such as trees.Credit: Marek Uliasz/Alamy
Although it’s not clear which policies work best, Gallo says that European countries are now better able to protect people than they were in 2003. Her next step is to assess the strategies key to achieving this. “Climate change needs to be considered as a health issue,” Gallo says, adding that extreme-weather events might be the easiest way for people to understand that.
Better data
Improved data collection is one thing that would help scientists to assess strategies’ effectiveness. For instance, many studies analysing the urban heat-island effect use satellite data, which tend to measure surface temperatures. Melissa McHale, an urban ecologist at the University of British Columbia in Vancouver, Canada, says that can lead to misguided policies.
She offers the example of painting roads and buildings white. “We realized when we were standing in those white places that it was really uncomfortable, but from the satellite it looked cooler,” she says. Instead of absorbing the Sun’s heat, white roads reflect it onto people — who experience radiant and ambient air temperatures rather than the surface temperature, she says. Although studies show that making roofs white can reduce temperatures in cities by a couple of degrees, painting roads white — as has been done in Phoenix, Arizona, and Los Angeles — could worsen the problem for pedestrians.
McHale is working with the city of Fort Collins in Colorado on which solutions to implement and where — such as the addition of trees to bus stops. Her team is measuring air temperatures around homes and analysing water and energy consumption — a hyper-local approach that she says will help the city to budget resources to improve people’s comfort.
She also suggests that cities dedicate more space to parks, but notes that this is difficult when balancing needs such as affordable housing and keeping water use low in arid places.
The idea of ‘depaving’ — tearing out roads and car parks and replacing them with green space — is growing in popularity in cities such as Portland, Oregon, and Amsterdam. “We’re addicted to the car, and it’s going to be hard to build liveable cities when we’re building cities for cars,” McHale says.
There is promise in the fact that cities are constantly being rebuilt, Luber says — the average construction turnover is 30–50 years. “Every single heat death can be prevented, we just need to have the resources and willingness to do it.”
The good news is that given the substantial accumulation of protection from past infections and vaccinations, the two most serious metrics—emergency department visits and deaths—have not shown similar rises. The weekly percentage of emergency department visits with a Covid-19 diagnosis is low and similar to last year’s summer wave. Deaths are likewise low, though they are still only provisional counts for the most recent weeks.
Emergency department (orange) visits and deaths (blue).
Chart: CDC
The FDA has firmly embraced a strategy to offer annual Covid-19 vaccines in the run-up to winter waves, not summer waves. The agency’s thinking has always been to encourage Americans to get their flu and Covid-19 vaccines together between September and November, just before a mob of cold-weather respiratory illnesses strike together. The fresh vaccination boost can dull the levels of severe respiratory disease at a time when health care systems are most at risk of becoming overwhelmed.
Seasonality
But, while seasonal flu and some other respiratory viruses reliably surge almost exclusively in the winter, the seasonality of Covid-19 was never a given. And, so far, summer waves have arisen as consistently as winter ones, creating some awkwardness for the vaccine releases.
Some experts have recommended getting a Covid-19 vaccine to protect against the summer surge. “Now is the time to get a dose with this surge,” Michael Osterholm, director of the Center for Infectious Disease Research and Policy at the University of Minnesota, told CNN on Sunday.
However, the only vaccines currently available target last year’s strains (related to the XBB.1.5 omicron variant), which are long gone and may not offer strong protection against current strains (JN.1 and KP.2 omicron variants). Even if the 2024–25 KP.2-targeting vaccine is approved by the FDA this week and hits pharmacy shelves next week, a dose takes two weeks to produce full protection. By that time, the summer wave will likely be declining. In fact, it looks to have already peaked in some parts of the country, including in some southern and western areas.
The other thing to consider is timing for maximum protection for the likely winter wave. For healthy people 5 years old and above, the CDC recommended getting only one shot last year. The shots offer peak protection for around four months. If you get your annual shot at the beginning of September, your protection may be on the decline if Covid-19 peaks again at the turn of the year, as it has the past two years.
According to the 2023–24 guidance, people who are 65 and older can get a second Covid-19 booster four months after getting their first. People who are moderately or severely immunocompromised may also get additional doses of the updated Covid-19 vaccine.
Last month, Brazil celebrated breaking ground on what it hopes will become the first maximum-security biosciences laboratory in Latin America. Many researchers are excited at the prospect of a facility where they can safely study the most dangerous pathogens in the region. However, some wonder about the cost of maintaining such a lab and are concerned about the pushback they are sure to receive from members of the public over housing deadly organisms there.
The need for a biosafety-level-4 (BSL-4) laboratory in Brazil is unquestionable, says Flávio Fonseca, a virologist at the Federal University of Minas Gerais in Belo Horizonte, Brazil. “We have seen the number of epidemic, even pandemic, outbreaks increase in the last 100 years,” he says. When an outbreak happens, researchers want to be able to work safely with the live virus to understand it and to develop vaccines and treatments.
“We’re sitting on a powder keg” in terms of pathogens that might emerge in Latin America, says Fernando Spilki, a veterinary virologist at Feevale University in Novo Hamburgo, Brazil, agreeing that such a facility is necessary. In particular, humans are clearing more and more of the Amazon rainforest for agriculture and other uses, and so are frequently coming into contact with animals that can harbour previously unknown viruses. And climate change is driving some species out of remote locales and into more populated areas. “We need a laboratory like this so we can give quick responses” to these challenges, Spilki says.
A first for Latin America
The lab, dubbed Orion, is being constructed at the Brazilian Center for Research in Energy and Materials (CNPEM) in Campinas, about 100 kilometres northwest of São Paulo, and is scheduled to be complete by 2026 and operational by 2028. It will also host lower-level biosafety labs, including BSL-2 and BSL-3 facilities.
BSL-4 labs are the most secure of the bunch. In these facilities, isolated from the others, researchers work with pathogens that can be transmitted through the air, that are deadly and for which there are no vaccines or treatments. Scientists must shower and change clothes before entering and leaving; while they are in the labs, they wear specially designed suits connected to a separate air supply.
Brazilian President Luiz Inácio Lula da Silva (centre, in grey jacket) joined CNPEM staff members on 4 July to dedicate the first stone for Orion.Credit: Igor Do Vale/ZUMA via Alamy
According to a report last year by the Global BioLabs initiative, run by researchers at George Mason University in Fairfax, Virginia, and King’s College London, there are 51 BSL-4 labs in operation around the world. Around 70% are in Canada, Europe or the United States. Another 18 are in planning or under construction, including Orion, which is the only one in Latin America.
Having a BSL-4 lab in Brazil could mean more autonomy for the country’s science, Fonseca says, allowing researchers to study local pathogens and develop treatments domestically, rather than travelling to labs elsewhere to do research and then queuing to receive diagnostic tests and vaccines. Five haemorrhagic-fever-causing arenaviruses — which can be studied only in a BSL-4 lab — have been detected in South America. In particular, Sabiá virus was first reported in São Paulo.
Challenges ahead
Once construction on Orion is complete, it will be the first BSL-4 facility in the world equipped with a synchrotron: a particle accelerator that produces high-powered radiation for imaging. Scientists will be able to use three X-ray beamlines derived from the CNPEM campus’s existing synchrotron, Sirius, to reveal the structures of pathogens and the dynamics of how they infect cells, tissues and small organisms.
COVID prompts global surge in labs that handle dangerous pathogens
Connecting the beamlines to a maximum-containment laboratory will, however, be a challenge, says Harry Westfahl, director of the Sirius facility. The beam hardware will need regular calibration and maintenance, so will have to be outside the BSL-4 part of the lab. But “we found a solution”, he says. The beams will pass through an optically transparent recess in a wall separating the synchrotron from the max-security lab. The hardest part, Westfahl says, has been designing that recess so that it is an effective barrier, can stand up to the disinfection required in the BSL-4 facility and is of sufficient optical quality to minimize interference with the precision of the incoming beams.
Another challenge for Orion will be training staff members to work in a type of facility that is new for the region. The facility must also develop a regulatory framework to ensure that risky experiments have oversight from a governing panel, and must install security measures to prevent unauthorized access by people or organizations that might intentionally release pathogens, says Gregory Koblentz, a biodefence specialist at George Mason University and a co-author of the 2023 Global BioLabs report.
Tatiana Ometto, the CNPEM’s high-containment biosafety specialist, acknowledges that Brazil doesn’t yet have an oversight mechanism for BSL-4 experiments. “But with Orion, discussions are taking place,” she says. “The Ministry of Health has created a working group to follow, monitor, assess and propose directives for the lab’s development.”
Concerns about proper biosafety and security at such labs have become heightened since the start of the COVID-19 pandemic. The first cases of infection with the coronavirus SARS-CoV-2 were spotted in Wuhan, China, where researchers at the Wuhan Institute of Virology were studying coronaviruses gathered from bats. Although much scientific evidence points to SARS-CoV-2 being passed from a wild animal to humans, some scientists say that an accidental leak from a lab can’t be ruled out.
Biosecurity concerns are important at all BSL-4 labs globally, not just in Brazil, says Juliette Morgan, South America regional director for the US Centers for Disease Control and Prevention, who is based in Brasília. She points out that the CNPEM team has “a very clear understanding of the implications of a BSL-4” lab and has been seeking advice to fill any gaps.
Lab maintenance
The cost of the lab has also been a point of concern. The Brazilian government is investing $1 billion reais (about US$180 million) into Orion’s construction.
“There’s no doubt about the need for a laboratory of this kind in Brazil,” says Odir Dellagostin, president of the Brazilian National Council for State Funding Agencies. “But we lack the funds for other very important research” projects, he adds. In particular, he says, maintaining the facility will be very expensive. In 2022, Thomas Ksiazek, head of high-containment operations at Galveston National Laboratory, a BSL-4 facility in Texas, told Nature that his lab required almost US$12 million a year for maintenance and operations — $2 million of which was spent on 24-hour security.
CNPEM director Antônio José Roque da Silva says that Orion is less expensive to build than other BSL-4 facilities. “The average cost of a lab like this in the United States is about a billion dollars,” he says. “We’re using one-fifth of that to build one that will allow greater research autonomy.” He does admit, however, that maintenance will be a burden. CNPEM, he adds, is seeking funds from other ministries and sources now to “build a resilient system”.
“Our strategy uses a small amount of designer solvent to absorb plastic particles from a large volume of water,” said Gary Baker, an associate professor in the University of Missouri’s Department of Chemistry. Credit: Sam O’Keefe/University of Missouri
A team at the University of Missouri has devised a method to eliminate most nanoplastics from water using eco-friendly solvents, suitable for both fresh and saltwater applications.
Nanoplasticst are an emerging enemy of human health. Much smaller in size than the diameter of an average human hair, nanoplastics are invisible to the naked eye.
Linked to cardiovascular and respiratory diseases in people, nanoplastics continue to build up, largely unnoticed, in the world’s bodies of water. The challenge remains to develop a cost-effective solution to get rid of nanoplastics while leaving clean water behind.
Now, researchers at the University of Missouri have developed a revolutionary liquid-based solution that eliminates more than 98% of these microscopic plastic particles from water. This method, detailed in new study published in ACS Applied Engineering Materials, promises significant advancements in water purification technology.
Gary Baker, an associate professor in the University of Missouri’s Department of Chemistry, looks at a bottle of a new liquid-based solution that eliminates more than 98% of microscopic plastic particles from water. Credit: Sam O’Keefe/University of Missouri
“Nanoplastics can disrupt aquatic ecosystems and enter the food chain, posing risks to both wildlife and humans,” said Piyuni Ishtaweera, a recent alumna who led the study while earning her doctorate in nano and materials chemistry at Mizzou. “In layman’s terms, we’re developing better ways to remove contaminants such as nanoplastics from water.”
Innovative Purification Methods
The novel method — using water-repelling solvents made from natural ingredients — not only offers a practical solution to the pressing issue of nanoplastic pollution but also paves the way for further research and development in advanced water purification technologies.
Once mixed with water and allowed to reseparate, the solvent floats back to the surface, carrying the nanoplastics within its molecular structure. Credit: Sam O’Keefe/University of Missouri
“Our strategy uses a small amount of designer solvent to absorb plastic particles from a large volume of water,” said Gary Baker, an associate professor in Mizzou’s Department of Chemistry and the study’s corresponding author. “Currently, the capacity of these solvents is not well understood. In future work, we aim to determine the maximum capacity of the solvent. Additionally, we will explore methods to recycle the solvents, enabling their reuse multiple times if necessary.”
Scaling and Future Applications
Initially, the solvent sits on the water’s surface the way oil floats on water. Once mixed with water and allowed to reseparate, the solvent floats back to the surface, carrying the nanoplastics within its molecular structure.
In the lab, the researchers simply use a pipette to remove the nanoplastic-laden solvent, leaving behind clean, plastic-free water. Baker said future studies will work to scale up the entire process so that it can be applied to larger bodies of water like lakes and, eventually, oceans.
This illustration outlines the two-step extraction method. Credit: Gary Baker
Implications and Next Steps
Ishtaweera, who now works at the U.S. Food and Drug Administration in St. Louis, noted that the new method is effective in both fresh and saltwater.
“These solvents are made from safe, non-toxic components, and their ability to repel water prevents additional contamination of water sources, making them a highly sustainable solution,” she said. “From a scientific perspective, creating effective removal methods fosters innovation in filtration technologies, provides insights into nanomaterial behavior and supports the development of informed environmental policies.”
The Mizzou team tested five different sizes of polystyrene-based nanoplastics, a common type of plastic used in the making of Styrofoam cups. Their results outperformed previous studies that largely focused on just a single size of plastic particles.
Reference: “Nanoplastics Extraction from Water by Hydrophobic Deep Eutectic Solvents” by Piyuni Ishtaweera, Colleen L. Ray, Wyland Filley, Garrett Cobb and Gary A. Baker, 4 June 2024, ACS Applied Engineering Materials. DOI: 10.1021/acsaenm.4c00159
