Three Major Scientific Controversies About Coronavirus-Prism

Face masks, number of cases, and virus immunity remain topics for which scientists are still controversial.

Political leaders have closed borders in response to Covid-19, but scientists are more involved than ever. But the coronavirus is novel, and we don’t yet have all the facts about it. As a result, as new scientific data comes in, we may need to change our approach.

This does not mean that science is not reliable. You will get an overall picture over time. And there’s already great research that can help inform political decisions. Here are three topics scientists disagree with:

Face mask

The new coronavirus spreads by coughing, sneezing, and splashes from speech. Face masks are obligatory in many countries to stop the spread of the virus.

However, there is much debate among scientists about the effectiveness of face masks in reducing Covid-19 diffusion. A report from an interdisciplinary group convened by the Royal Society Come out in agreement Of the public wearing face masks. These documents have not been peer-reviewed, but they claim that face covers can help reduce transmission of Covid-19 when widely used in situations where physical distances are not possible.

One of the smaller clinical trials found that infected children wearing masks Did not pass the virus For family contacts.

But science is complex. Face masks do not prevent the wearer from inhaling small airborne particles of coronavirus that can cause infections. According to a recent study, wearing a mask Give a false sense of securityThat is, the wearer may ignore other important infection control measures.

Research also shows that when people wear masks, the exhaled air To see.. This creates a visible impulse. Also, if your hands are contaminated, you can get infected. In fact, the WHO warns that masks can be counterproductive except for the wearer Don’t touch their face Adopt other control measures.

I also know that face masks can make us breathe More often and deeper — Possibility of spreading polluted air.

As a result, many scientists disagree with the Royal Society’s report and seek more evidence of the effectiveness of masks. Ideally, a randomized controlled trial of many people in the entire population would be needed to track how masks affect the number of infections.

However, other scientists argue that face masks should be used, even though they lack complete credible evidence— For your safety.. After all, without vaccines, the strongest weapons we have are basic precautions such as regular hand washing and social distance.

Immunity

Immunologists are working hard to determine what immunity to Covid-19 looks like. Much of the research focuses on so-called “neutralizing antibodies,” B cellsIt binds to viral proteins and prevents direct infection.

Studies show that levels of neutralizing antibodies remain high for several weeks after infection, but usually begin to decline. Peer-reviewed studies in China show that infected people There was a sharp drop Antibody levels within 2-3 months of infection. This raises the question of whether people will be protected for a long time from subsequent exposure to the virus. If this study Proved to be accurate —Results need to be corroborated by other studies—it could affect whether it is possible to produce a vaccine with long-term immunity.

Many scientists believe that antibodies are the key to immunity, but other immune cells called T cells, which are produced when the body encounters molecules that fight viruses called antigens, are also involved. Some people argue. They may become programmed to fight the same or similar viruses in the future. And research is about T cells At work In many patients fighting Covid-19. Even those who have never been infected Harbor protection T cell They have been exposed to similar coronaviruses.

A recent study by the Swedish Karonliska Institute has not done a peer review yet, but many people suffering from mild or asymptomatic Covid-19 Immunity through T cells — Even if the antibody cannot be detected. The authors believe this can prevent or limit reinfection, and estimate that one-third of asymptomatic Covid-19s can have this type of immunity. But how it works and how long it lasts is unclear.

If this is the case, it’s very good news. This means that public immunity to Covid-19 is probably much higher than the antibody test suggested. Possibility of producing “population immunity” (that is, enough people infected with the virus) with a low infection rate of 20% instead of the widely accepted 60-70 Some argue that there is. But this claim Still in dispute..

The immune response to Covid-19 is complex and the overall picture may exceed antibodies. To understand, you need to do long-term, large-scale studies with both T cells and antibodies How long the immunity lasts How are these different components of Covid-19 immunity related?

Number of cases

Coronavirus case reports vary widely around the world. Less than one person has been reported to be infected in some areas, and in other areas More than half of the population I have Covid-19. One peer-reviewed study estimated only 35 pc of symptomatic cases Has been reported In the United States, this figure is even lower in some other countries.

When it comes to estimating true prevalence, scientists use only one of two major approaches. They either test a sample of people in the antibody population and report their numbers directly, or use mathematical models to predict how the virus affected the population. Such a model gave Very different quotes.

Although a study led by the University of Toronto in Canada has not been peer-reviewed, it has assessed blood test data from people around the world and found that the percentage Varies by country..

I do not know why. The actual age, health, prevalence, or policies to control viral infections in each population can make the difference. However, it is most likely due to differences in methodologies such as antibody tests (serologic tests): different tests Different sensitivity..

In antibody research, 14 pc of person There were Covid-19s in the UK, 19 in Sweden and 3 in Yemen. However, it excludes T cells. Their numbers can be much higher if they provide a reliable guide to the infection — in some areas it may be closer to herd immunity — but this Highly debated..

This article First published in The Conversation Reproduced with permission.