About 46 million Americans are now fully vaccinated against COVID-19 — some 18% of all U.S. adults — according to the Centers for Disease Control. California state data says about 17% of people ages 16 and up here are fully vaccinated.
As more people get their shots and more businesses reopen, a lot of people want to know: Now what? How much of our lives can we resume? We can go to the movie theater, go to the gym, and eat at a restaurant indoors — but should we?
KCRW asked listeners to send questions about what you should and shouldn’t do once you’re fully vaccinated. To help answer them, we turn to: Dr. Monica Gandhi, an infectious disease expert at UC San Francisco; Joseph Allen, a professor at Harvard’s T.H. Chan School of Public Health, where he directs the Healthy Buildings program; and Omai Garner, the director of clinical microbiology for the UCLA Health System.
Is the end of the pandemic near?
Monica Gandhi: “I do think the end of this pandemic is near. I think that essentially the minute that the Pfizer press release came out on November 9, about these highly effective vaccines, it could only get better from there. We had a terrible third surge. Now we got out the vaccine. We’re getting it out maybe not as fast as Israel and the UK, so we can look to those countries and see how low their hospitalizations and cases are with even higher rates of vaccination.”
Omai Garner: “While I think it's cautiously optimistic, I agree that … we are on our way out of this pandemic. But I think there are a lot of questions still to answer. … While we may be further ahead than a lot of the world, getting out of this pandemic is really a global challenge.”
Joseph Allen: “I share that optimism. ... We're quite fortunate to have multiple very effective and safe vaccines. And we can look to international data to see what our future looks like. When we get a high percentage of people vaccinated, things start to look very good, very fast. We're in a key transition period here in the U.S. … Once we're done with the U.S., of course, our job is not done. This is a global equity issue. And so we're just getting started in that regard.”
Listener question: I recently received my second vaccine dose. Is it safe to visit and hug a vaccinated parent indoors without a mask? What about attending outdoor events?
Gandhi: “Yes, it is perfectly safe for vaccinated people to hug. I encourage them to hug. It's time to hug. My parents actually just visited me. They're 87 and 81. And they're here right now. And we're hugging a lot. … Outdoor activities, of course, are very safe. We went to an outside restaurant the minute they got off the plane.”
When fully vaccinated, should we still do more things outside than inside?
Allen: “That's going to be the case for a lot of reasons. I agree that once we're vaccinated, the risks are significantly reduced. Especially as more and more people get vaccinated, then the level of circulating cases drops as well. It's clear from the beginning of this pandemic that time outdoors is much lower risk than time indoors. And if you're going to spend time indoors, you want to increase the airflow.
… As hundreds of millions are vaccinated in the U.S., things go away, like plexiglass should go away, it never should have been there in the first place. But things like better ventilation should stay all the time. We know this is associated with reduced infectious disease transmission in a typical year. So beyond COVID, there are some practices that should have been here all along and should stay after we get a handle on COVID.”
Why should plexiglass go away? Isn’t it an effective barrier, in case someone is coughing or sneezing in front of you?
Allen: “There are real limited instances where plexiglass is useful. If people were wearing a mask first, that's going to capture a lot of the respiratory droplets and aerosols, depending on the quality of the mask. And plexiglass is going to be good for what we call ‘ballistic droplets,’ the respiratory droplets that really go straight, and aerosols go right around that plexiglass.
And so there are some limited incidents where I think this is okay and even useful. A cashier at a grocery store, that's great, they’re seeing maybe 100 people pass them in the hour.
You have to be careful with plexiglass in that it can actually impede or interfere with good airflow, right. The way buildings are designed, the way airflow comes in, if you … start putting up barriers, you can actually create little pockets of highly concentrated air.
And in fact, a new report just came out today that showed … within-school transmission was rare when good controls were in place. They did identify ... a small cluster in the main office, and their subsequent investigation revealed that plexiglass was impeding the airflow exactly as we predicted. So if you're going to do it, you have to be really careful and thoughtful and be sure you're not disrupting good airflow.”
Listener question: Shouldn't we wait a bit longer to open up and mingle until more people are vaccinated, just to see how the case rate is going?
Garner: “I agree with that sentiment. You know, I think that, again, there will be distinctly different suggestions and rules for vaccinated and unvaccinated individuals. But to be honest, walking around Los Angeles over the last week or two, you'd think everybody was vaccinated, by the way people have dropped the public health measures.
And so I do think we have to be careful, and I think that it still needs to be emphasized that unvaccinated individuals need to maintain social distancing practices and masking. Because as we've seen in a lot of other countries, and unfortunately I think we may see here, there may be another, hopefully much smaller, surge due to the lack of public health guidelines following by unvaccinated individuals.
… But COVID is just right there. It's just waiting for more individuals that are susceptible to be infected, and then the numbers will turn around very quickly.”
What about variants? Some evidence just came out in the “New England Journal of Medicine” that a very small percentage of people who are fully vaccinated are getting COVID again. They tested thousands of LA-area health care workers, and found that seven out of nearly 15,000, so .04%, got COVID after being fully vaccinated. Is that because of the variants? Is that something we should be worried about?
Garner: “I really think that when you look at the studies that ask whether people are getting COVID and they’re vaccinated, the question for the study is did they progress to symptomatic disease? Or were they just asymptomatically carrying the virus? And I think what you'll find is that progressing to symptomatic disease for COVID when you're fully vaccinated, and two weeks past your second shot, is exceptionally rare but could happen.
We've had some cases at UCLA where it has happened, but it has happened in people that were more likely immune compromised than the general population. So maybe they didn't make an appropriate response to the vaccine, and that's why they caught COVID.
For asymptomatic screening, when you just do PCR and look for carriage of the organism, there have been studies out of the U.K. that show that that is also dramatically reduced in a vaccinated individual, but it can still happen. Which is why the CDC guidelines talking about vaccinated people going around high-risk unvaccinated people is really for protection against that potential carriage.”
Listener question: Can parents who are fully vaccinated host indoor playdates with kids whose parents are also fully vaccinated, even though none of the kids are vaccinated? Should we worry about potentially infecting the kids? What if the children are immunocompromised or have asthma?
Gandhi: “Yes. I do think they can have playdates inside with non-vaccinated children. And the reason I say that is because there have been many studies relevant to this question. There have been many studies in the real world, and not clinical trials, where the possibility of you transmitting the virus after you've been fully vaccinated is very low.
I think the best study that I've seen is the one published in “Clinical Infectious Disease” from the Mayo health care system, where people who are just asymptomatically swabbed before surgeries are 80% less likely to have even asymptomatic carriage in their nose than people who are unvaccinated. And so I think there's no doubt in my mind that these real world studies show that transmission is much reduced after you've been vaccinated.
Which then goes back to the playdate question, that all the parents being fully vaccinated are likely not going to be able to pass it on to children in the household. Children are very, very luckily much less at risk for susceptibility to severe COVID. So that's why I think it's safe to be in this household with unvaccinated children. If they're immunocompromised, asthma actually isn't a risk factor for severe COVID-19, strangely. But if they're immunocompromised in other ways, then I'd be more careful.”
What if you're fully vaccinated, but another adult in your house is not? Should you be worried about your possible asymptomatic spread of it to that person?
Gandhi: “In the same way that we were talking about how the real world data is showing us that after vaccination, you are so unlikely to have it in your nose, to have asymptomatic infection, and to pass it on to others, that real world data has to be incorporated into our discussions of the vaccine, since the clinical trials didn't actually answer those questions.
So no, you're very unlikely to pass it on. ... But absolutely, I would feel safe being around your unvaccinated family number in the household after vaccination.”
Listener question: Can I travel out of state to visit a friend who is also vaccinated? The CDC has very strict guidance when it comes to traveling and hasn't really changed its guidance, saying only that you should avoid nonessential air travel.
Gandhi: “I disagree with that in the sense that I understand that a public health agency has to be super cautious. And so I think it's hard to figure out all the things to caution against, but I do think that planes, especially because it's mandated ... are safe, actually. They actually have a surprising amount of ventilation. And you should absolutely mask on the plane. Do not let down your guard as a vaccinated person. But the ventilation is very reassuring to me, as are the low numbers of super spreader events on planes. And I would feel very comfortable going and visiting a vaccinated friend on a plane.”
The TSA says that more than a million passengers a day are flying between airports. And that's been happening for about the last two weeks. How big a risk is transmission in airports and on airplanes?
Allen: “I think we have to separate out the two factors there. … We're in this transition phase, and until we get there, where the vast majority are vaccinated, we do have to be cautious. And of course, airplanes are excellent vectors for moving potentially infectious people around the country.
That said, I've studied air quality on airplanes for over a decade. In 2013, I was the lead author of a National Academies report on infectious disease transmission in airports and on airplanes. And I agree with Monica entirely. The risks on the airplane are quite low. And this goes back with decades of research. And also from this virus. We're just not seeing airplanes as hotbeds of transmission.
... The air in an airplane is bled off the engine in nearly all airplanes. It’s called ‘bleed air.’ And you get about a 50-50 mix of fresh air from outside, virus-free of course, and recirculated air. And the recirculated air all goes through HEPA filters, and HEPA filters capture, at minimum, 99.97% of airborne particles, and it's delivered right at the person. So you have good ventilation, good ventilation effectiveness. You get about 10 to 20 air changes per hour. For reference, in your home, you get half an air change per hour, for a typical home in the U.S.
So for those reasons, the time on the airplane is lower risk. That doesn't mean everybody should go out and be traveling around, especially those who are not vaccinated. And there are other areas of the travel experience that I think are higher risk. And this would make sense. In the airport at a restaurant, mask down, anytime, that's the case, just like in any other restaurant.
Also, we flagged this in the 2013 report, and I'm not sure how many airlines are doing this, but when planes are at the gate, they don't always run their ventilation system. I think that's a problem too. We've measured carbon dioxide during boarding of airplanes, and we find the CO2 concentrations can get quite high. And that's because you have a lot of people in a small volume space. And if those engines aren't running with the auxiliary power units, or gate base ventilation is not going, you can have a build up. So when I think about air travel, those are the areas that concern me the most.
When the systems are operating, you have great airflow, and then now, with the extra protection of mask wearing, I would consider that low individual risk. But higher risk from a population perspective, if we have a lot of unvaccinated people traveling around the country.”
Listener question: I've paused dating since March of last year. Is it safe to date and do all the other things that are part of dating?
Garner: “I think that a lot of that is about vaccinated status. So if a vaccinated person is dating another vaccinated person, then they can interact in a pre-pandemic way, let's say. But if somebody is unvaccinated, or two people are unvaccinated, then it represents sort of an equivalent risk, and probably shouldn't happen.
So the door is starting to open, I think, for people to resume their dating lives. I think the challenge there is ... how do you know if a person that you just met is actually vaccinated? Or they're just telling you that they're vaccinated? And how do the dating apps handle this? I think that there's a lot that potentially some experts can go down that particular road and how that's going to be affected. But according to the CDC guidelines, I would feel that two vaccinated individuals can feel free to date.”
So on their first date, they should ask to see each other's vaccination cards?
Garner: “I think it's going to be part of the conversation, right?”
Gandhi: “It has in HIV. People see each other's cards or whatever. It's certainly been used. We call it ‘Vac sorting,’ or ‘sero sorting’ in HIV. ... We've been calling it this in San Francisco dating, when you know each other's vaccination status.”