Covid-19 rarely spreads through surfaces. So why are we still deep cleaning?

‘Armed with a year’s worth of data about coronavirus cases, researchers say one fact is clear. It’s people, not surfaces, that should be the main cause for concern. Evidence from superspreading events, where numerous people are infected at once, usually in a crowded indoor space, clearly point to airborne transmission, says Marr. “You have to make up some really convoluted scenarios in order to explain superspreading events with contaminated surfaces,” she says.

‘Hand washing is crucial, says Marr, because surface transmission can’t be ruled out. But it’s more important to improve ventilation systems or to install air purifiers than to sterilize surfaces, she says. “If we’ve already paid attention to the air and we have some extra time and resources, then yes, wiping down those high-touch surfaces could be helpful,” she says.

‘Households can also ease up, says Pickering. Quarantining groceries or disinfecting every surface is going too far. “That’s a lot of work and it also is probably not reducing your exposure that much,” she says. Instead, reasonable hand hygiene, as well as wearing a mask and social distancing to reduce exposure from close contacts is a better place to focus efforts.’

Read here (Nature, Jan 29, 2021)

How to redesign Covid vaccines so they protect against variants

‘Some aspiring vaccine makers have had their eye on the threat that escape variants might pose from the start. A team at Gritstone Oncology decided to focus on this potential problem by designing a vaccine that targets multiple sites on several viral proteins, in contrast to first-generation shots that target only the spike protein, says Andrew Allen, president of the company in Emeryville, California. The hope is that the vaccine, which should soon start clinical trials, will make it difficult for the virus to evade immunity because many genetic changes would be necessary for it to do so. “You can either play whack-a-mole and chase the variants, or you can try to get ahead of them,” Allen says.

‘Because updating the construction of existing vaccines is relatively simple, a new RNA vaccine could be designed and manufactured for clinical testing within six weeks, Weissman estimates. But that is only the beginning. “Mass-producing a vaccine is hard. To start all over again will be hard,” says Offit. Some researchers are expecting periodic updates to coronavirus vaccines, as with flu, to become a way of life. “This is not unusual,” says Stanley Plotkin, a consultant who advises companies on vaccines. But it could mean that worries over supply chains and logistics will continue for some time.’

Read here (Nature, Jan 29, 2021)

Covid’s toll on smell and taste: What scientists do and don’t know

‘Early in the COVID-19 pandemic, it emerged that many people infected with the SARS-CoV-2 virus were losing their sense of smell — even without displaying other symptoms. Researchers also discovered that infected people could lose their sense of taste and their ability to detect chemically triggered sensations such as spiciness, called chemesthesis.

‘Almost a year later, some still haven’t recovered these senses, and for a proportion of people who have, odours are now warped: unpleasant scents have taken the place of normally delightful ones. Nature surveys the science behind this potentially long-lasting and debilitating phenomenon:

• How many people with COVID-19 lose their sense of smell?
• Why do people with COVID-19 lose their sensitivity to smells?
• How quickly do the impaired senses return?
• How does permanently losing the chemical senses affect a person?
• Are treatments available for restoring these senses?

Read here (Nature, Jan 14, 2021)

How kids’ immune systems can evade Covid

‘Their immune system sees the virus “and it just mounts this really quick and effective immune response that shuts it down, before it has a chance to replicate to the point that it comes up positive on the swab diagnostic test”, says Melanie Neeland, an immunologist who studied the family, at the Murdoch Children’s Research Institute in Melbourne, Australia.

‘Even in children who experienced the severe but rare complication called multisystem inflammatory syndrome in response to SARS-CoV-2 infection, studies report that the rate of positive results on RT-PCR range from just 29% to 50%.‘

Read here (Nature, Dec 10, 2020)

Why emergency Covid-vaccine approvals pose a dilemma for scientists

‘Immunizations are speeding towards approval before clinical trials end, but scientists say this could complicate efforts to study long-term effects...

‘Once a vaccine is granted emergency approval, there is pressure on developers to offer the immunization to trial participants who received a placebo. But if too many people cross over to the vaccine group, the companies might not have enough data to establish long-term outcomes, such as safety, how long vaccine protection lasts and whether the jab prevents infection or just the disease.

“It’s a real vaccine-development dilemma,” says Klaus Stöhr, who formerly headed vaccine design at the pharmaceutical company Novartis in Cambridge, Massachusetts, and is now retired. Still, Stöhr thinks that the vaccine should be granted emergency-use authorization, because its effectiveness has been established and there is a dire need.’

Read here (Nature, Nov 23, 2020)

What the data say about asymptomatic Covid infections

‘Research early in the pandemic suggested that the rate of asymptomatic infections could be as high as 81%. But a meta-analysis published last month1, which included 13 studies involving 21,708 people, calculated the rate of asymptomatic presentation to be 17%...Byambasuren’s review also found that asymptomatic individuals were 42% less likely to transmit the virus than symptomatic people.’

Read here (Nature, Nov 20, 2020)

Memo for President Biden: Five steps to getting more from science

‘The list of needed actions is long, but here we highlight five that the Biden administration should take swiftly. We call not for a return to business as usual but for fundamental, sometimes counter-intuitive changes that will strengthen the use of science in US policy and by the research community more broadly... (1) Let an oft-overlooked White House office [Office of Science and Technology Policy] lead the pandemic response. (2) Make advisory processes more independent. (3) Expedite scientific-integrity legislation.  (4) Give public universities tough love and lots of support. (5) Refocus science funding.

Read here (Nature, Nov 8, 2020)

Why schools probably aren’t Covid hotspots

‘Data gathered worldwide are increasingly suggesting that schools are not hot spots for coronavirus infections. Despite fears, COVID-19 infections did not surge when schools and day-care centres reopened after pandemic lockdowns eased. And when outbreaks do occur, they mostly result in only a small number of people becoming ill. However, research also shows that children can catch the virus and shed viral particles, and older children are more likely than very young kids to pass it on to others. Scientists say that the reasons for these trends are unclear, but they have policy implications for older children and teachers.’

Read here (Nature, Oct 29, 2020)

How anti-ageing drugs could boost Covid vaccines in older people

‘Unlike fine wine, the human body does not improve with age. Hearing fades, skin sags, joints give out. Even the body’s immune system loses some of its vigour. This phenomenon, known as immunosenescence, might explain why older age groups are so hard-hit by COVID-19. And there is another troubling implication: vaccines, which incite the immune system to fight off invaders, often perform poorly in older people. The best strategy for quelling the pandemic might fail in exactly the group that needs it most...

‘[Eric] Verdin [president and chief executive of the Buck Institute for Research on Aging in Novato, California] agrees that supporting the older immune system should be a priority. “I think the net result of all this will be renewed interest in understanding the defect in the immune response in the elderly.” That has implications not only for the coronavirus, but also for a host of other diseases, including other viral infections and even cancer. “COVID-19 has brought to the front something that a lot of people have ignored.”

Read here (Nature, Oct 14, 2020)

How Trump damaged science — and why it could take decades to recover

‘As he seeks re-election on 3 November, Trump’s actions in the face of COVID-19 are just one example of the damage he has inflicted on science and its institutions over the past four years, with repercussions for lives and livelihoods. The president and his appointees have also back-pedalled on efforts to curb greenhouse-gas emissions, weakened rules limiting pollution and diminished the role of science at the US Environmental Protection Agency (EPA). Across many agencies, his administration has undermined scientific integrity by suppressing or distorting evidence to support political decisions, say policy experts. “I’ve never seen such an orchestrated war on the environment or science,” says Christine Todd Whitman, who headed the EPA under former Republican president George W. Bush.

‘Trump has also eroded America’s position on the global stage through isolationist policies and rhetoric. By closing the nation’s doors to many visitors and non-European immigrants, he has made the United States less inviting to foreign students and researchers. And by demonizing international associations such as the World Health Organization, Trump has weakened America’s ability to respond to global crises and isolated the country’s science.’

Read here (Nature magazine, Oct 7, 2020)

Who gets a Covid vaccine first? Access plans are taking shape

‘The WHO’s guidance at this point lists only which groups of people should have priority access to vaccines. The NASEM (US National Academies of Sciences, Engineering, and Medicine) guidance goes a step further by ranking priority groups in order of who should get a vaccine first (see ‘A tiered approach’).

‘After health-care workers, medically vulnerable groups should be among the first to receive a vaccine, according to the NASEM draft plan. These include older people living in crowded settings, and individuals with multiple existing conditions, such as serious heart disease or diabetes, that put them at risk for more-serious COVID-19 infection.

‘The plan prioritizes workers in essential industries, such as public transit, because their jobs place them in contact with many people. Similarly, people who live in certain crowded settings — homeless shelters and prisons, for example — are called out as deserving early access.’

Read here (Nature, Sept 16, 2020)

Fast coronavirus tests: What they can and can't do

‘Rapid antigen tests are designed to tell in a few minutes whether someone is infectious. Will they be game changers? At present, antigen tests are administered by trained professionals, but some companies are developing versions that are simple enough to be used at home — similar to pregnancy tests.

“Making the tests faster, cheaper, easier is definitely the goal — and I think the antigen test is the way to get there,” says Martin Burke, a chemist at the University of Illinois at Urbana-Champaign, who is co-developing rapid tests, including antigen-based assays. “This is by no means the perfect solution, it’s just the fastest thing we could get going now,” he says.

Read here (Nature, Sept 16, 2020) 

The coronavirus is mutating — does it matter?

‘Different SARS-CoV-2 strains haven’t yet had a major impact on the course of the pandemic, but they might in future...

‘It’s even possible that the D614G change could make the virus an easier target for vaccines, Montefiori’s team found in a study posted to bioRxiv in July 13. Mice, monkeys and humans that received one of a number of experimental RNA vaccines, including one being developed by drug maker Pfizer in New York City, produced antibodies that proved more potent at blocking G viruses than D viruses.

‘With G viruses now ubiquitous, the finding is “good news”, says Montefiori. But as a scientist who has watched HIV mutate to elude many vaccines developed against it, he remains wary of the potential of SARS-CoV-2 to evade humanity’s responses. Luban agrees: “We need to keep our eyes open for additional changes.”

Read here (Nature, Sept 8, 2020)

How many people has the coronavirus killed?

‘In times of upheaval — wars, natural disasters, outbreaks of disease — researchers need to tally deaths rapidly, and usually turn to a blunt but reliable metric: excess mortality. It’s a comparison of expected deaths with ones that actually happened, and, to many scientists, it’s the most robust way to gauge the impact of the pandemic. It can help epidemiologists to draw comparisons between countries, and, because it can be calculated quickly, it can identify COVID-19 hotspots that would otherwise have gone undetected. 

‘According to data from more than 30 countries for which estimates of excess deaths are available (see ‘Terrible toll’), there were nearly 600,000 more deaths than would normally be predicted in these nations for the period between the onset of the pandemic and the end of July (413,041 of those were officially attributed to COVID-19).’

Read here (Nature, Sept 1, 2020)

The coronavirus is most deadly if you are older and male — new data reveal the risks

‘For every 1,000 people infected with the coronavirus who are under the age of 50, almost none will die. For people in their fifties and early sixties, about five will die — more men than women. The risk then climbs steeply as the years accrue. For every 1,000 people in their mid-seventies or older who are infected, around 116 will die. These are the stark statistics obtained by some of the first detailed studies into the mortality risk for COVID-19.’

Read here (Nature, August 28, 2020)

Sex differences in COVID-19 immune responses affect patient outcomes

‘Yale researchers have identified significant differences in how the immune systems of women and men respond to the virus that causes COVID-19. In a study launched by Women’s Health Research at Yale and published Aug. 28 in Nature, the authors revealed possible biological explanations for why men are more likely than women to suffer severe cases of COVID-19 and die of the disease.

“We now have clear data suggesting that the immune landscape in COVID-19 patients is considerably different between the sexes and that these differences may underlie heightened disease susceptibility in men,” said senior author Akiko Iwasaki, the Waldemar Von Zedtwitz Professor of Immunobiology and Molecular, Cellar and Development Biology, and an investigator of the Howard Hughes Medical Institute. “Collectively, these data suggest we need different strategies to ensure that treatments and vaccines are equally effective for both women and men.”

Read here (Yale News, August 26, 2020)

The unequal scramble for coronavirus vaccines — by the numbers

‘Wealthy countries have struck deals to buy more than two billion doses of coronavirus vaccine in a scramble that could leave limited supplies in the coming year. Meanwhile, an international effort to acquire vaccines for low- and middle-income countries is struggling to gain traction.’

Read here (Nature, August 24, 2020)

How to stop Covid-19 fuelling a resurgence of AIDS, malaria and tuberculosis

‘A focus on the coronavirus has disrupted detection and treatment of other infectious diseases. Governments and funders can do four things to avert a catastrophe.

‘First, hospitals and health authorities in affected cities and regions must recognize that AIDS, malaria and TB are surging again... Second, researchers must continue to refine their models using more real-world data... Third, there is a need for public-information campaigns... Fourth, these campaigns cannot on their own keep surgeries and wards open, or equipment functioning. The resurgence of infectious diseases has created a greater demand for tests, treatments and research. All of these need more funding.’

Read here (Nature, August 12, 2020)

Two decades of pandemic war games failed to account for Donald Trump

‘The scenarios foresaw leaky travel bans, a scramble for vaccines and disputes between state and federal leaders, but none could anticipate the current levels of dysfunction in the United States...

’Perhaps the biggest limitation of simulation exercises was that they didn’t actually drive policymakers to prioritize and fund improvements to the public-health system. Morrison [J. Stephen Morrison, director of global health policy at the Center for Strategic and International Studies in Washington DC] now questions whether it’s even possible to do that through simulations alone, or whether people must experience an epidemic at first hand. After more than 70 people in Taiwan died as a result of SARS in 2003, the government mapped out its emergency-response network. “Every year since then, for the past 17 years, they’ve held annual outbreak exercises and practised, practised, practised,” Morrison says...

’Now, the United States has experienced a tragedy, too. The daily number of new COVID-19 cases broke records throughout much of July, after many states attempted to reopen their economies. Frieden [Tom Frieden, a former director of the US Centers for Disease Control and Prevention (CDC)] says that one of the most crucial actions now is for health departments to strengthen their response systems by analysing data in real time, so that they can tailor interventions as needed. “The best public-health programme is a programme that uses real-time data to make real-time decisions,” he says. “Real life is our exercise.”

Read here (Science Magazine, August 4, 2020)

Scathing Covid-19 book from Lancet editor — rushed but useful

‘Now [Richard] Horton has a book of his own. The COVID-19 Catastrophe is a sort of history, diagnosis and prescription, in real time. It is wide ranging, querying the changing role of international cooperation and the fallout of austerity economics, and taking a deeper dive into China’s scientific and political response to the crisis than most Western media have offered. But the book returns again and again to the catastrophe in both the United Kingdom and the United States. It is haunted by the question: how did two of the richest, most powerful and most scientifically advanced countries in the world get it so wrong, and cause such ongoing pain for their citizens?’

Read here (Nature, June 18, 2020)