We bring you up to speed on the science behind the most urgent questions about the virus and the disease. We demystify the research and help you understand what it really means. I'm Tanya Lewis. I'm Josh fishman. And we're scientific Americans, senior health editors. Today, we'll talk about the plan for a second vaccine booster shot. The prospects of a new COVID wave and whether people will put on masks to stop it. And how to think about COVID risk when it comes to everyday activities. This week, the FDA authorized a second booster shot on top of the ones given last year. That would be four shots total for me, Tanya. Why this new one. It happens sooner than I expected Josh, although the scientific community had been debating whether additional booster shots were needed for some time. Normally, the FDA holds a meeting of its advisory committee before deciding whether to authorize vaccines or boosters. But that didn't happen this time. The move makes boosters available to adults age 50 and older and anyone 12 and older who is immunocompromised, four months after their first booster shot. For people who had two shots and a booster, this would be their fourth shot. For some immunocompromised folks, this would be their 5th shot. That's a bunch of jabs. Why does the FDA think we need this new one? It was based on some evidence that immune protection against severe disease wanes over time in these groups. A recent CDC report found that protection against hospitalization waned from 91% to 78%, four months after a third dose. But some experts are not convinced that a second booster shot will significantly improve immunity. It may top up antibodies for a few months, but at a certain point with additional shots, we may see diminishing returns. For those who haven't gotten their first booster yet, that is important to do, and if you're older or higher risk, you might want to consider getting a second booster after four months to top up your protection. It seems like many people have ditched their masks and health officials are allowing it. But if a new COVID surge comes, Josh, will people put them on again? That's a really important question, because some kind of surge is coming, and we know masks stop infections. The effectiveness of a good mask like an N95 is beyond dispute, as you've pointed out, Tanya, and we will face more COVID, infections and hospitalizations have started to rise in Europe. The new BA two variant is becoming more common there and in the U.S., and like Europe we've cut back on masks and on restrictions. So we're likely to see something a spike a surge or whatever you want to call it. It's not clear how big it will be. But if it gets above a certain level, we should put masks back on, according to the CDC. If cases and hospitalizations per 100,000 people in your area jump up by 20 hospitalizations a week, if you're starting from a low level of cases, then put on a mask when you're indoors with other people. But masks aren't just health aids. During the pandemic, they've become political symbols. Some people are really pro mask and others are adamantly opposed to them. Exactly. So how's that going to play out in the future? I ask an expert on mask attitudes, Emily mendenhall, a medical anthropologist at Georgetown university. She just published a book called unmasked based on research and communities in Iowa and in California. Emily's talked with us about masks on an earlier episode. She says anti mask feelings stem partly from perceptions of low disease risk. People would unmask if they weren't worried about themselves. Maybe they were younger and didn't think the disease would make them sick, and partly it was political. People said they didn't want governments dictating their behavior. They had legitimate worries about business closures, and their ability to make a living. But it was also about making a public show of defiance. Masks got caught up in all that. Pro mask feelings come from an idea that we faced a collective risk. In the street, Emily says, people would talk about the need to work together and protect one another, and obviously they also felt they were in danger as individuals, and they trusted government guidelines. As the pandemic has worn on, these collective worries have faded in many places, and mask wearing is faded with them. Without actual rules such as mandates, people in those areas are unlikely to put masks back on. But Emily says there's another group that we overlook. The sometimes maskers. That's about one in three people in her research. They're all political moderates, sometimes government does a good job, they say, and sometimes not. Sometimes the media is trustable, other times not so much. And sometimes they wear a mask. There are huge swaths of Americans who would put on a mask if they were around someone with a weak immune system, or someone older, or at risk in some way. So the focus should be on sometimes maskers. That's who's willing to listen to mask promotion if COVID starts to peak in their communities. It's a sizable group, Emily says, they could be part of making mask wearing seem normal, especially in times of danger, and making it normal is key. Emily still thinks mandates are important, but she understands there's a lot of resistance. If these sometimes maskers put on N95s, they could start a whole surge of protection. Clearly, people are growing tired of restrictions as we head into pandemic year three. Many are eager to get back to doing things they enjoy again. Is there a smart way to evaluate any risks as we venture out more often? We're definitely getting to the point, Josh, where people are tired of wearing masks of social distancing and avoiding the people in places they enjoy. But the virus hasn't gone away, and it isn't likely to anytime soon. There will always be some level of risk, but as with everything in life, we have to find ways to balance risks with benefits. One of our freelancers, is working on a story for us about this. He asked a number of experts in epidemiology, risk assessment and related fields, how they make their own decisions about COVID risk. We can think about risk in three different ways, they said. There's personal risk, which is the risk of you or people in your household contracting COVID. There's community risk, which is the likelihood of encountering someone with COVID in your local community, and there's exposure risk, which accounts for the chances of getting COVID from a particular setting based on things like airflow and the behavior of other people. Caitlyn jetliner, an epidemiologist at the University of Texas Houston, says that age is the biggest personal risk factor, followed by having certain comorbidities or being immunocompromised. She estimates that vaccinated and boosted people in their 60s have a ten times higher likelihood of dying from severe breakthrough cases than 18 to 49 year olds. People who are at higher risk should talk with their doctors about what risks or reasonable..