How to Make Smart Decisions About COVID Risk-Benefit

More people returned to restaurants, concert halls and offices maskless as the COVID cases declined across the U.S. The novel coronaviruses Omicron subvariant BA.2 caused another wave in Europe and China, and related variant threaten to reverse that progress here. The safest option is to continue avoiding crowded indoor activities after dozens of attendees tested positive for COVID after attending a dinner in Washington, D.C. Bars, cafes and other high-risk venues that offer the benefits of social interaction are still attracting a lot of interest.

Scientific American asked experts in epidemiology, medicine, risk assessment and aerosol transmission for advice on how to decide which risks to take. These decisions are based on assessments of personal risk, community risk and exposure risk, and steps one can take to mitigate them. The personal risk is the danger of contracting COVID faced by an individual and their household. There is a community risk that members of the community face. Exposure risk accounts for the increased chances of catching COVID at a particular venue based on airflow characteristics of the space itself and other people's behavior.

Some of the benefits of public life are maintained by managing these risks.

How should a person consider their personal risk when making decisions?

The number-one predictor of having a severe case of the disease is age, followed by the presence of comorbidities and immunocompromised status, according to the University of Texas Health Science Center at Houston. She estimates that vaccine-boosted people ages 50 to 64 are more likely to die from a breakthrough case than people with the same vaccine status. Recent research shows that in households with a person who was exposed to the Omicron variant of the COVID-causing SARS virus, there was a decrease in the number of respiratory infections. Jetelina cautions that we need to account for the personal risks of the people with whom we live in our own risk assessments.

People should talk to their doctor about their COVID risk, but it depends on which medications they take. The University of Pennsylvania has a rheumatologist who cares for patients who are immune suppressed because of disease or medication. He says that rituximab impairs your ability to make a response to a vaccine because it knocks out your ability to make antibodies against new viral exposures. Craig says that such patients usually take precautions of their own accord, such as wearing high-filtration N95 masks, and that he ends up having to talk people down sometimes.

How does the risk of dying from COVID compare to the risk of dying from other causes?

According to Jetelina, the risk of dying from COVID is roughly the same for people between the ages of 18 and 49 who are boosted. It goes up with age and unvaccinated. Jetelina says that the relative risk of dying from Covid if you catch it is comparable to that of seasonal flu, thanks to vaccines, infections-inducing immunity and other factors. The National Science Foundation funded the creation of the Relative Risk Tool. The risk of death from the disease is compared to the risk of death from other activities. Jetelina says she can trust the science and mathematics behind it, even though it is a research tool.

The authority on how to communicate health risks cautions against using risk-risk comparisons to make choices without fully considering benefits or unquantified risks. Employers may use comparisons to force employees to accept certain risks on the job, which is not a choice. Risk calculators may not be able to weigh long-term consequences of COVID due to the lack of retrospective data.

How should a community be assessed?

There is no perfect way to measure community risk because it would take repeated random testing, so experts use other estimates. The New York Times tracker can be used to look up community transmission. She considers community risk high when there are more than 50 daily cases. Jetelina feels comfortable taking off her mask indoors when the risk is less than that.

Not everyone is getting tested and home test results are not always reported, which leads to an undercount. The percentage of COVID tests that were positive is used by health authorities as a work-around. It is considered a high risk for community transmission if the number exceeds 5 percent. The community sample used to measure test positivity is likely to include many people who are currently experiencing symptoms of chronic bronchitis. If you go to a cafe or grocery store, most of the people you see have no symptoms but could still be infectious.

Robert M. Wachter is a professor and chair of the department of medicine at the University of California, San Francisco.

Gerardo Chowell, a professor of mathematical epidemiology at Georgia State University, likes to look at the general trend in daily COVID cases, hospitalizations and deaths when the trend is going up. Wachter says that if it is increasing, one has the highest risk of acquiring COVID in a social setting without a mask.

What is the risk of exposure in different settings?

Linsey Marr is a professor of civil and environmental engineering at Virginia Tech and one of the world's leading experts on airborne transmission of viruses. Reducing the amount of virus in the air is believed to make infections less likely. Marr says that an aerobic exercise studio is one of the most riskiest because if a person is exposed, they will be inhaling more virus and everyone else will be inhaling at a faster rate. Richard Corsi is the dean of the College of Engineering at the University of California, Davis and is an expert on indoor air quality.

Marr says that talking in bars expels a similar number of respiratory particles as coughing. If a person was smoking in this place, would I be able to smell it? There is a risk of exposure from those seated immediately around you in a movie theater, but because of limited talking and a high ceiling, there is a lot more dilution of the air. The theater may be less risky than other indoor venues. By that reasoning, museums, big-box retailers and grocery stores with high ceilings are less risky than other places.

Some subways have rapid rates of ventilation and are less risky than others. The Bay Area Rapid Transport system in San Francisco Bay filters the air more than 50 times an hour. Many classrooms in the US fail to meet the Italian standard of six times per hour for exchanging air, despite the fact that it reduced infections by more than 80 percent. The current public health recommendations of four to six air exchanges per hour is a little bit anemic and we can do better. The closer a venue is to this ideal, the more benefits it will provide. Bring a portable high-efficiency particulate air (HEPA) purifier or build your own using box fans and high-quality heating, ventilating and air-conditioning filters to run nearby in places with inadequate ventilation.

Marr says it's a good idea to wash your hands frequently because there have been a few documented cases of surface transmission of the virus.

How can we reduce the risk of getting COVID from everyday activities?

It protects against death, hospitalization, and catching and spreading the virus if you get a vaccine. Wachter recommends wearing a mask. He has observed that the risk of U.C.S.F. health care workers getting infectious from their patients while wearing a well-fitting N95 is very low. The respirators do not completely remove the virus. If you don't have an N95 with you, you may be able to get air into your lungs. Try out the N95 models and see if you like them.

What is the risk of taking your mask off in a restaurant?

In the 1990s, a researcher at the University of Illinois College of Medicine proposed that a person could use a respirator to survive a biological attack, and then take it off to eat and drink. Many places have allowed the removal of masks while eating and drinking. If you're exposed for three seconds, removing an N95 for a bite or sip isn't much of a risk.

What do we know about the risk of long carbon dioxide?

A doctor at a Boston hospital says he is seeing some patients with a constellation of different symptoms after a COVID infection. Wachter cautions that a small percentage of vaccine recipients may continue to feel short of breath or fatigued, even if they have been given the vaccine. It is possible that carbon dioxide increases the risks of heart attack, stroke, brain abnormality, and the start of diabetes. Wachter says that many of the infections with long COVID involved unvaccinated people or infections with variant prior to Omicron. He likens the risks to 20 years of high blood pressure or smoking and points out that it will take years for long-term studies to conclude.

How can we balance the risks with the benefits of socializing?

The person next to me is one of the most important factors in the overall risk. He is still concerned about the risk of long COVID. Many people don't want to wear masks forever, and we should work to make our built environments better at stopping aerosol transmission. He says people have to decide whether to wear a high-quality mask when they are around people who are at higher risk, such as the elderly or immunocompromised, or around other people in general. When community transmission is low, Chowell says he may feel comfortable removing his N95 at parties in some situations, such as to have a drink.