Annual Reviews: Keyword search for query

How optimizing indoor humidity can help stop the spread of Covid and flu

Richard Zare — Wed, 23 Aug 2023 00:00:23 GMT

OPINION: Recent CDC guidelines for indoor air quality disregard the benefits of humidity. But research shows it can kill viruses and help thwart infections.

How to recover from the Great Education Disruption

Prachi Srivastava — Wed, 15 Mar 2023 00:00:15 GMT

OPINION: Children around the world were out of school for months, with big impacts on learning, well-being and the economy. How do we avoid a ‘generational catastrophe’?

Covid, RSV and the flu: A case of viral interference?

Amber Dance — Thu, 12 Jan 2023 00:00:12 GMT

The ‘tripledemic’ unfolding this winter is one of several odd trends among respiratory virus infections these last years. Viruses, it turns out, can block one another and take turns to dominate.

What next-gen Covid-19 vaccines might look like

Bob Holmes — Thu, 03 Nov 2022 00:00:03 GMT

From building up defenses in the nose to slowing down a virus’s ability to make copies of itself, scientists are rolling out a raft of creative approaches to fighting infection

How to fight Covid with light

Chris Baraniuk — Thu, 29 Sep 2022 00:00:29 GMT

Some wavelengths of light in a range called far-UVC kill microbes in experiments and appear to be harmless to people. Could they be used to make indoor spaces safer against the coronavirus?

How long will it take to understand long Covid?

Marla Broadfoot — Mon, 08 Aug 2022 00:00:08 GMT

Covid long-haulers experience a litany of symptoms, and researchers have proposed a variety of theories to explain them. It’s a morass to figure out, but the answers are important for the multitudes still suffering from an infection that happened to them months or even years ago.

The pain of prolonged grief disorder

Alison McCook — Mon, 28 Mar 2022 00:00:28 GMT

Psychologists are beginning to understand that for some people, intense and sustained feelings of loss are symptoms of a serious condition — one that can last for years and erode wellbeing

Pandemic psychology: Nothing new under the Sun

Steven Taylor — Tue, 08 Mar 2022 00:00:08 GMT

OPINION: Our behavior during Covid-19 echoes that of individuals, societies and governments during past plagues. We can and should do better.

How to short-circuit short-term thinking

Paul Van Lange and David Rand — Mon, 31 Jan 2022 00:00:31 GMT

OPINION: Human behavior is fueling major social dilemmas — from climate change to the Covid pandemic to the spread of misinformation. But that means it’s also the solution, if only we can harness psychology for the common good.

How zinc helps you fight off infections

Diana Kwon — Thu, 23 Dec 2021 00:00:23 GMT

Our bodies require the vital mineral for the healthy functioning of the immune system

Question the ‘lab leak’ theory. But don’t call it a conspiracy.

Ivan Oransky — Tue, 23 Nov 2021 00:00:23 GMT

OPINION: If there’s one thing the pandemic has taught us, labels get in the way of facts and make the truth that much harder to find.

Let’s change how we pay for hospitals

John Colmers and Sherry Glied — Mon, 01 Nov 2021 00:00:01 GMT

OPINION: Many health facilities were already in fiscal straits before Covid-19 — except in Maryland. The state’s innovative and sound approach could be the answer to rescuing systems nationwide.

Why we are developing a patent-free Covid antiviral therapy

Alpha Lee, John Chodera and Frank von Delft — Mon, 27 Sep 2021 00:00:27 GMT

OPINION: During global health crises such as pandemics, drug discovery should be publicly funded and open, with no research secrets locked away

To understand airborne transmission of disease, follow the flow

Anil Ananthaswamy — Sat, 04 Sep 2021 00:00:04 GMT

Viruses and bacteria travel in fluids, such as the air we breathe. Studying exhalations, toilet flushes and rain drops, with math and modeling, can sharpen the big-picture view of how to prevent infections.

Why don’t kids tend to get as sick from Covid-19?

Sara Reardon — Thu, 02 Sep 2021 00:00:02 GMT

Some children have been hospitalized and some have died, but at a tiny fraction of the adult rate. As children head back to school, scientists are hoping that research will provide answers.

Building an immune system for the planet could prevent the next pandemic

David Bray — Tue, 03 Aug 2021 00:00:03 GMT

OPINION: We need a global information network that spans borders so we can spot — and stop — new pathogens before they threaten world health

What will history say about Covid? Museums scurry to collect — and prepare to remember.

Karen Emslie — Fri, 30 Jul 2021 00:00:30 GMT

A worn pair of nurse’s shoes. That coronavirus model Anthony Fauci used in public briefings. Oral histories, iconic photos and social media posts. All of us are curators now, and what we preserve — as well as what we don’t — will write the pandemic story.

Covid cut pollution and got us outside. Let’s keep it up.

Ebba Malmqvist — Mon, 19 Jul 2021 00:00:19 GMT

OPINION: Urban planners need to find ways to reduce traffic and provide equal access to green spaces

Demographers tackle Covid-19

Eryn Brown — Thu, 15 Jul 2021 00:00:15 GMT

What they learn could help steer the future of public health

The science of habits

Stephanie Parker — Thu, 15 Jul 2021 00:00:15 GMT

If you’re trying to break a bad habit or start a good one, psychologists have some tips

A year of missing tests

Amber Dance — Tue, 13 Jul 2021 00:00:13 GMT

Standardized tests for K-12 students were largely dropped during Covid, leaving a gaping hole in our understanding of students’ progress.

Pencils down: The year pre-college tests went away

Amber Dance — Tue, 13 Jul 2021 00:00:13 GMT

Many colleges and universities stopped requiring the SAT and ACT during Covid. Will they go back to testing in the future? Select: (a) Yes (b) No (c) Depends (d) Not enough information.

Let’s put community health workers to work

Miya Barnett — Thu, 08 Jul 2021 00:00:08 GMT

OPINION: Covid laid bare the scope of health disparities in the US and around the world. Research shows that trained lay people may be the best way to bring evidence-based care to those who need it most.

What Sweden’s Covid failure tells us about ageism

Carl-Johan Karlsson — Wed, 07 Jul 2021 00:00:07 GMT

Experts say that growing age discrimination in the West is a result of policies that far predate the pandemic

Let’s keep meetings virtual after Covid

Katherine H. Freeman and Raymond Jeanloz — Tue, 15 Jun 2021 00:00:15 GMT

OPINION: We don’t want to go back to living on planes and out of suitcases. Virtual meetings are cheaper, more accessible and better for the planet.

The promise and perils of life lived online

Nicola Jones — Wed, 09 Jun 2021 00:00:09 GMT

The pandemic has immersed us faster and deeper in immersive communication technologies. It’s a disrupted, confusing, sometimes exhausting world — but shifting both the tech and our expectations might make it a better one.

Covid job loss: The cause of the next epidemic?

Jennie E. Brand and Sarah A. Burgard — Tue, 25 May 2021 00:00:25 GMT

OPINION: Being out of work — even for a just a few months — may be bad for your health

It’s time for a government reset — and the ideas are flourishing

M. Mitchell Waldrop — Fri, 21 May 2021 00:00:21 GMT

It started with thinking about sustainability. But after the many traumas of 2020, a lot of people are determined to make some fundamental changes in the machinery of governance.

Remote work can be a lot better than this

Ariane Ollier-Malaterre — Mon, 26 Apr 2021 00:00:26 GMT

OPINION: Under the right conditions (i.e., not during a pandemic), telework can be great for both employers and employees

Ah, wilderness! Is nature the tonic we’ve needed for pandemic malaise?

Chris Baraniuk — Wed, 21 Apr 2021 00:00:21 GMT

As Covid-19 descended across the world, people sought refuge in gardens, parks and the woods. But it’s hard to measure how being in nature affects our well-being — and how we can best reap its rewards.

Four ways HIV activists have saved lives during Covid

Monica Gandhi — Tue, 13 Apr 2021 00:00:13 GMT

OPINION: We owe these early fighters a debt of gratitude for transforming our response to public health crises.

Know thine enemy: Why genetic sequencing is key to tracking Covid-19

Amber Dance — Fri, 09 Apr 2021 00:00:09 GMT

The US effort to analyze viral genomes, slow to start, is now picking up speed

Yes, all this screen time is hurting your eyes

Zhong-Lin Lu — Fri, 09 Apr 2021 00:00:09 GMT

OPINION: A neuroscientist says that he’s particularly worried about kids, who may have spent much of last year learning online. Some easy hacks can help.

How to convince people to accept a Covid-19 vaccine

John H. Tibbetts — Wed, 31 Mar 2021 00:00:31 GMT

Hesitancy rates are falling but they’re still sizable, especially among certain groups. Easy access and trusted community messengers are keys to moving the needle.

Growing a more resilient global food system

Bob Holmes — Fri, 19 Mar 2021 00:00:19 GMT

Covid-19 has been a stress test for the world’s food supply chains — and a preview of looming threats. That’s making efforts to improve the journey from farm to fork more urgent than ever.

Friendly fire: How autoantibodies could drive severe Covid

Amber Dance — Fri, 19 Mar 2021 00:00:19 GMT

Some serious cases of Covid-19 are linked with the immune system’s attack on the body it’s trying to protect

Solving the pandemic’s drinking problem

David Adam — Mon, 15 Mar 2021 00:00:15 GMT

The Covid-19 lockdown has changed alcohol habits, but public health researchers face a blurred and incoherent picture of who’s been drinking, and how much

The danger of high public debt is not what you think

Edgar Kiser — Fri, 12 Mar 2021 00:00:12 GMT

OPINION: An overlooked consequence of huge deficit spending during the Covid-19 pandemic could be further loss of public trust in the government

Another way that Covid can kill: Car crashes

Marisa Auguste and Eric Jackson — Wed, 10 Mar 2021 00:00:10 GMT

OPINION: Traffic is down, but deaths are up. Here’s how to stay safe on the road.

The varied landscape of universal health care

James Gaines — Tue, 09 Mar 2021 00:00:09 GMT

There’s more than one way for a nation to achieve universal coverage for its residents. Here are the systems of six different countries.

How health insurance is faring under Covid

Lola Butcher — Tue, 09 Mar 2021 00:00:09 GMT

Millions of Americans lost employer-sponsored coverage when Covid-19 disrupted their jobs. Can America come up with a better system?

How the pandemic could change architecture

Greg Miller — Mon, 01 Mar 2021 00:00:01 GMT

COMIC: Covid-19 has inspired a rethink of how we design and use our built environments

Abortions can happen safely — and entirely — at home

Leah Coplon and Claire Brindis — Tue, 23 Feb 2021 00:00:23 GMT

OPINION: The pandemic has taught us how we can deliver better care to patients who seek to terminate pregnancies. Now if only science could triumph over politics.

Coronavirus evolving: How mutations arise and new variants emerge

Diana Kwon — Mon, 22 Feb 2021 00:00:22 GMT

COMIC: As it spreads throughout the world, the virus that causes Covid-19 has been changing. Scientists are tracking those changes, hoping to stay one step ahead of worrisome strains.

Don’t let Covid boost another killer

Mohan P. Joshi — Wed, 17 Feb 2021 00:00:17 GMT

OPINION: The pandemic may be interfering with our fight against drug-resistant bacteria. Luckily, the same tactics can beat back both scourges.

How online misinformation spreads

Marcus Woo — Thu, 11 Feb 2021 00:00:11 GMT

Misinformation is running rampant. To slow this infodemic, researchers are tracking how it spreads on social media.

The challenges of antiviral treatments

Amber Dance — Tue, 09 Feb 2021 00:00:09 GMT

Antibiotics abound, but virus-fighting drugs are harder to come by, and Covid-19 amply shows how much we need them. Fortunately, scientists are getting better at making and finding them.

Will small businesses recover from Covid?

Eryn Brown — Sat, 06 Feb 2021 00:00:06 GMT

They play an outsize role in the economy, and in strengthening communities. Their prospects for surviving the pandemic may seem dim, but there are some encouraging signs, experts say — and emerging winners and losers.

Pandemic behavior: 4 takeaways, 2 experts and 1 big opportunity

Evan Nesterak of Behavioral Scientist — Thu, 04 Feb 2021 00:00:04 GMT

OPINION: So many things about this global health crisis come down to people’s small, day-to-day actions. What have we learned so far?

How enlisting dentists can speed up Covid-19 vaccinations

Mary E. Northridge — Wed, 03 Feb 2021 00:00:03 GMT

OPINION: Dental care providers have the skills, the facilities and the trust of patients who might otherwise miss out

Kids of the Covid generation: The road ahead

Amber Dance — Wed, 03 Feb 2021 00:00:03 GMT

What will become of children growing up during the pandemic? There’s reason for concern, but the research on resilience is reassuring. A developmental psychologist explains what adults can do to protect youngsters from long-term harm.

Are too many scientists studying Covid?

Julie K. Pfeiffer and Terence S. Dermody — Fri, 29 Jan 2021 00:00:29 GMT

The pandemic prompted many scientists to pivot their research to the coronavirus. That’s not an entirely good thing.

The dash to adapt smartwatches to help detect Covid infections

Matthew Hutson — Wed, 27 Jan 2021 00:00:27 GMT

Wearable devices already collect vital signs like heart rate and skin temperature. New algorithms can use them to catch illness early — leading to urgent efforts to help battle the pandemic.

How to help Covid-19 long-haulers

Syra Madad and Theodore Long — Mon, 18 Jan 2021 00:00:18 GMT

OPINION: Patients with lingering symptoms need access to specialized clinics — and so much more

Don’t abandon paid sick leave. It’s a cost-effective tool against Covid-19.

Stefan Pichler and Nicolas R. Ziebarth — Thu, 14 Jan 2021 00:00:14 GMT

OPINION: Requiring companies to give unwell workers compensated time off isn’t a burden. It’s smart public health policy that reduces the spread of disease.

The enduring allure of conspiracies

Greg Miller — Thu, 14 Jan 2021 00:00:14 GMT

Conspiracy theories seem to meet psychological needs and can be almost impossible to eradicate. One remedy: Keep them from taking root in the first place.

A winter of despair for homeless families

Ellen Bassuk — Thu, 07 Jan 2021 00:00:07 GMT

OPINION: In the absence of much-needed measures, the pandemic will make the cold days harder and more perilous among our most vulnerable population

Virtual agents of change: How computers are mapping Covid-19’s future

Bob Holmes — Tue, 15 Dec 2020 00:00:15 GMT

Traffic planners, securities traders and military strategists all use it. Simulating the behavior of millions of idiosyncratic individuals also may be the best way to understand complex phenomena like pandemics.

How men can ‘lean in’ on behalf of women

W. Brad Johnson and David G. Smith — Thu, 10 Dec 2020 00:00:10 GMT

OPINION: Women have been pulled away from their jobs during the pandemic. Here’s what they need right now from male allies in the office.

Protecting great apes from the unknown effects of Covid-19

Jackie Rocheleau — Thu, 03 Dec 2020 00:00:03 GMT

Humans can transmit many diseases to chimps, orangutans and their kin. People who study and care for the creatures are taking lockdown-style measures to limit the risk.

How researchers are making do in the time of Covid

Anil Ananthaswamy — Wed, 02 Dec 2020 00:00:02 GMT

The coronavirus pandemic has shuttered labs and sidelined scientists all over the world. Here’s a look at how some of them have coped.

American individualism and our collective crisis

Anil Ananthaswamy — Tue, 01 Dec 2020 00:00:01 GMT

Our national and social identity is deeply rooted in values like freedom, equality and order. A political scientist explores how these ideas affected the US response to the pandemic.

Evolution of the US public health system

Lola Butcher — Tue, 17 Nov 2020 00:00:17 GMT

TIMELINE: From colonial efforts to control smallpox outbreaks to antimalarial campaigns targeting mosquitoes, the American effort grew for centuries. But cutbacks have weakened it in the past decades.

Pandemic puts all eyes on public health

Lola Butcher — Tue, 17 Nov 2020 00:00:17 GMT

Covid-19 has exposed the weak spots of the US public health system — and that presents an opportunity, says an epidemiologist, for the nation to recognize the problems and act to fix them

I got the Pfizer Covid-19 vaccine. Or maybe not.

Amber Dance — Tue, 10 Nov 2020 00:00:10 GMT

OPINION: Many Americans say they won’t take a vaccine. I am not one of
them — and I have the shots to prove it.

Covid stole my Dad’s final months

Alison McCook — Mon, 09 Nov 2020 00:00:09 GMT

OPINION: Because of the pandemic, I couldn’t visit him in his nursing home, and because of his dementia he couldn’t understand why. Mismanagement of this crisis has failed the elderly and caused incalculable hurt.

How the pandemic could globalize the economy even more — not less

Eryn Brown — Thu, 05 Nov 2020 00:00:05 GMT

Closed borders, trade conflicts and supply-chain problems raise the specter of nations turning inward and disconnecting from one another. But Princeton’s Harold James thinks Covid-19 may well push us all closer.

It’s not just the germs — it’s also the genes

Tim Vernimmen — Tue, 03 Nov 2020 00:00:03 GMT

Pathogens can make us sick. Just how sick depends on genetic variations, including ones that sabotage immune molecules called interferons. A better understanding could lead to new treatments for Covid-19 and other scourges.

7 ways to fix this pandemic — and stop the next one

Eric Toner — Thu, 29 Oct 2020 00:00:29 GMT

OPINION: Experts predict another nearly 180,000 deaths by February. It doesn’t have to be that way, writes health security expert Eric Toner.

Wanted: Online gamers to help build a more stable Covid-19 vaccine

Rhiju Das and Martin Skladany — Tue, 20 Oct 2020 00:00:20 GMT

OPINION: People beat artificial intelligence hands-down at puzzling out new ways to fold molecules for a potential SARS-Cov-2 immunization. Thousands more players are needed.

The pernicious contagion of misinformation

Bob Holmes — Fri, 02 Oct 2020 00:00:02 GMT

False statements — about Covid-19 and so much else — spread like a virus online. Scientists should study them like one.

How we bury our dead during a pandemic

Stephanie Parker — Thu, 24 Sep 2020 00:00:24 GMT

Funerals, burials and other ways of communally commemorating those who have died have always been part of human history. The need for social distancing has upended these psychologically important rituals and fostered creative alternatives.

Eviction’s long reach

Megan Jula — Wed, 23 Sep 2020 00:00:23 GMT

A “scarlet E” can be the catalyst for a chain reaction of calamities, and Covid-19 piles on

Viruses that come to stay

Amber Dance — Tue, 15 Sep 2020 00:00:15 GMT

Some linger in the body for a lifetime. The one causing Covid-19 probably isn’t one of them, but it and others can create mischief long after the immune system appears to have banished them.

I tested positive for Covid-19 antibodies — what now?

David Adam — Wed, 09 Sep 2020 00:00:09 GMT

As immunologists struggle to understand the immune response, psychologists want to know how infected people will think and behave after they recover

Blood clots: A major problem in severe Covid-19

Amber Dance — Wed, 26 Aug 2020 00:00:26 GMT

Out-of-control clotting can endanger some patients even after the virus has gone. Clinicians and researchers are trying to understand why it happens and how best to manage the problem.

The race to develop paper-based tests for coronavirus

Tien Nguyen — Fri, 21 Aug 2020 00:00:21 GMT

Scientists are working at breakneck speed to develop inexpensive tools that take only minutes to tell if someone is infected — a feat that could pave the way for a safer return to normalcy

Microbial secrets of sourdough

Bob Holmes — Wed, 12 Aug 2020 00:00:12 GMT

It all starts with a community teeming with yeasts and bacteria — but what’s really happening? Scientists peer into those jars on the kitchen counter to find out.

Why jobless payments serve the public good

Eryn Brown — Tue, 11 Aug 2020 00:00:11 GMT

Amid political debate over benefits during the pandemic, a researcher explains why unemployment insurance and other government measures are crucial for the economy and employees to survive troubled times

Getting a Covid-19 vaccine — quickly and safely

Eric Bender — Thu, 30 Jul 2020 00:00:30 GMT

Researchers around the globe are working with unprecedented speed to find the vaccines we need to find our way through the pandemic. What’s the bar for safety and effectiveness?

Pandemics in recent history

Knowable Magazine Staff — Thu, 16 Jul 2020 00:00:16 GMT

How viruses evolve: Lessons for the pandemic

Bob Holmes — Thu, 16 Jul 2020 00:00:16 GMT

Pathogens that switch to a new host species have some adapting to do. How does that affect the course of a pandemic like Covid-19?

Speaking of pandemics: The art and science of risk communication

Bob Holmes — Thu, 09 Jul 2020 00:00:09 GMT

Public health messages should be loud and clear, so that everyone listens and stays safe. But that’s easier said than done — especially with a case as complex as Covid-19.

How bats keep viruses at bay

Rachel Ehrenberg — Fri, 19 Jun 2020 00:00:19 GMT

Bats cope with myriad viruses, including the one causing Covid-19, with few ill effects. Scientists are probing their immune systems to fathom how they do it. The answers might help infected people, too.

Telemedicine’s tipping point

Lola Butcher — Wed, 17 Jun 2020 00:00:17 GMT

Sheltering in place has pushed virtual health care into the mainstream. Will we go back to doctors’ waiting rooms?

Mini-organs push along Covid-19 and other virus research

Amber Dance — Tue, 09 Jun 2020 00:00:09 GMT

While studies in mice and people can be slow, researchers are making fast progress testing medications in miniature airways and guts made of human cells

The challenge of conducting clinical research during a pandemic

Vijay Shankar Balakrishnan — Tue, 02 Jun 2020 00:00:02 GMT

Drug treatments and vaccines for Covid-19 are needed fast. But developing them in mid-outbreak is logistically hard and ethically tricky. A veteran vaccine researcher explains.

How we make decisions during a pandemic

Katherine Harmon Courage — Tue, 26 May 2020 00:00:26 GMT

From mask wearing to physical distancing, individuals wield a lot of power in how the coronavirus outbreak plays out. Behavioral experts reveal what might be prompting people to act — or not.

The time of trials: Waiting for a coronavirus vaccine

Bob Holmes — Fri, 22 May 2020 00:00:22 GMT

An infected and impatient world needs protection from Covid-19, but rushing it won't be easy. How can we speed up a complicated process?

Building a mouse squad against Covid-19

Anil Ananthaswamy — Thu, 14 May 2020 00:00:14 GMT

It began with an email from Wuhan, a Maine laboratory and mouse sperm from Iowa. Now that lab is on the verge of supplying a much-needed animal for SARS-CoV-2 research.

Loss of smell, confusion, strokes: Does Covid-19 target the nervous system?

Greg Miller — Tue, 12 May 2020 00:00:12 GMT

Reports of patients with neurological symptoms have emerged during the pandemic. Scientists don’t yet know whether these are a direct effect of the virus or part of the body’s response to infection.

Keys to coping with lockdown

David Adam — Thu, 07 May 2020 00:00:07 GMT

Studies on astronauts and Antarctic crews reveal how extreme confinement affects small groups. Scientists are racing to figure out isolation’s impact on the rest of us.

Covid-19 antibody testing: Tougher than true/false

Amber Dance — Fri, 01 May 2020 00:00:01 GMT

Antibodies should indicate if someone has had an infection in the past. But the promise of “immunity testing” is plagued by uncertainty about how the immune system responds to the coronavirus, as well as concerns about the tests’ accuracy.

Could Covid-19 usher in a new era of working from home?

Eryn Brown — Thu, 30 Apr 2020 00:00:30 GMT

Millions of people have been forced to work remotely — but experts say the practice won’t necessarily stick

How disease sleuths are using genomics to track the coronavirus

Bob Holmes — Tue, 21 Apr 2020 00:00:21 GMT

Rapid sequencing of viral genomes can help public health officials figure out the origins, spread and nature of quickly moving epidemics

Infectious disease: Making — and breaking — the animal connection

Tim Vernimmen — Thu, 16 Apr 2020 00:00:16 GMT

We know pathogens from other species can endanger us. Scientists are better equipped than ever to do something about it, but political buy-in is crucial.

What is a cytokine storm?

Amber Dance — Fri, 10 Apr 2020 00:00:10 GMT

An immune reaction gone wild seems to be linked with the most severe cases of pandemic Covid-19. Here’s what happens.

An old problem: How immune responses weaken with age

Jonathan Wosen — Wed, 01 Apr 2020 00:00:01 GMT

The body’s defenses lose flexibility and diversity over time, and protective responses to vaccines weaken as well. Scientists are working on ways to boost seniors’ protections against influenza, the novel coronavirus and other pathogens.

Digital disease surveillance: Tracking a pandemic

Katherine Ellison — Fri, 27 Mar 2020 00:00:27 GMT

Social media posts and online searches may offer vital clues about the spread of influenza — and now Covid-19. But they also risk errors and threaten privacy.

Closing in on the new coronavirus

Tim Vernimmen — Fri, 20 Mar 2020 00:00:20 GMT

The eye-catching spikes sticking out from the surface of SARS-CoV-2 may inspire new ways to prevent or treat Covid-19 infections