A New COVID Wave Is Here, Raising The Risk Of Reinfections

17:24 minutes

six white people walking on a european street. four people are walking towards the camera, two of which are wearing masks, and the two people not facing the camera walking away, appearing to not be wearing masks
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Coronavirus is surging again in the United States. The latest subvariants BA.4 and BA.5 are now dominant. Right now, things are feeling a little different: People who were recently sick are getting reinfected. And those who have so far evaded the virus are getting it for the first time. 

A new booster based on the new omicron subvariants is slated to roll out in the fall. Meanwhile, the Biden administration is pushing to allow people under 50 to get a second dose of the currently available booster.

Ira is joined by Katelyn Jetelina, adjunct professor at UTHealth School of Public Health and author of the newsletter, Your Local Epidemiologist and Jessica Malaty Rivera, epidemiology fellow at Boston Children’s Hospital and senior advisor at the Pandemic Prevention Institute to debunk the latest pandemic misinformation and update us on the current state of the virus.

Interview Highlights

Am I more likely to get reinfected with the latest Omicron variant?
Reinfection is much more likely than in past variants. According to Jetelina, 25% of new cases are from reinfections. Because an infection from the latest variant causes milder symptoms, your immune system mounts less of a defense the first time around (compared to earlier variants), making reinfection more likely. 

How soon could I get reinfected now?
Before less infectious variants, earliest reinfections often occurred after roughly 90 days. Now, that number seems to range from 60 to less than 30 days. 

“The purpose of vaccines is not to prevent infection,” said Jetelina. “The purpose of vaccines is to prevent severe disease and death.”

Am I more or less likely to have a severe infection the second time around?
You’re less likely to have a severe infection. Jetelina said she’s seen studies that show 60-90% lower odds of hospitalization and death with a reinfection compared to a primary infection. But that number is not 100%. People that are unvaccinated, older, or have comorbidities are more likely to have serious infections.

Should I just get infected to get it over with?
The virus doesn’t work like that, as we’ve seen with recent variants and increasing rates of reinfection. It’s not a good strategy, according to Rivera. She points out that there is still a risk of getting long COVID—and there are so many unknowns with that disease. (Learn more about the effects of long COVID, from a previous Science Friday segment.)

Should I get a second booster if my age group is eligible?
Boosters can prevent infection, especially if taken recently. They do this by increasing the number of antibodies that neutralize the virus. “The purpose of vaccines is not to prevent infection,” said Jetelina. “The purpose of vaccines is to prevent severe disease and death.”

Those who have received two boosters versus just one are about four times less likely to die from COVID-19, said Jetelina. Currently, less than 50% of the eligible population in the U.S. has received a booster dose. 

Will the Omicron boosters coming out this fall help protect against new variants?
By the time the Omicron booster is rolled out October, there will likely be a new Omicron subvariant taking hold. However, this booster will still broaden our protection no matter what Omicron subvariant is circulating. 

“The purpose of boosters and variant-specific boosters is not to chase the variant. We’re never going to win that rat race,” said Jetelina. 

Will there be another completely new variant, like Delta or Omicron, that’ll spread before or during the new booster release? Jetelina says the last estimate she saw gave that about a 30% chance of occurring. “So, it’s not zero, but it’s not a 100% chance,” she said.

Rivera cautions that while these new boosters will improve our protection against the virus, they are not a silver bullet to ending the pandemic. She urges people to continue masking, distancing, testing, and isolating if they are symptomatic, even once they receive the newest booster.

“Wearing a mask is a responsible thing to do,” said Rivera.

Should I be using rapid tests (antigen tests) or PCR tests?
While both are effective tools, they do different things. Rapid tests are a great indicator of active infection, less so for determining infectiousness. If you still have a dark second line on your test, odds are you have lots of virus in your system and you should be isolating. 

PCR tests, however, are extremely sensitive to the virus. You might’ve heard stories of people testing negative on rapids after a week or so, but positive on PCRs for weeks and even months after their initial COVID infection passed. Jetelina highly recommends rapid tests.

What if I have symptoms but I’m testing negative?
If you have symptoms, Jetelina says to assume you have COVID-19. You should isolate, and retest in about 24-48 hours. If, after that time, you test negative, you can be pretty sure that you had a false positive. 

While rapid tests are a great tool, they have a slightly harder time detecting the virus at the beginning of the infection, especially with Omicron variants. Jetelina says she’s seen strong evidence that an Omicron infection lasts 8-10 days. 

The CDC’s current quarantine guidelines are to isolate for five days after the onset of COVID symptoms, then wear a mask around other people for five additional days. Is that enough time?
“It’s not enough,” said Rivera. These guidelines are based on data from the Delta variant, not the Omicron variant, which is much more transmissible. 

“I have yet to meet a person who is asymptomatic and negative within five days in an Omicron infection,” said Rivera. 

False negatives are common in the early days of infection, so using a standard five day-long isolation and then five days of masking is not long enough to prevent spreading it to others. If you have any symptoms and if you are testing positive, that is a good sign that you are infectious. Rivera recommends staying home until you test negative on a rapid test and are asymptomatic. 

However, many people are required to go back to work after five days, even if they are still testing positive. If you must leave isolation, Jetelina recommends wearing a well-fitted and high-quality mask everywhere you go until you test negative again. 

Should I be wearing a mask indoors despite mask mandates being dropped around the country?
With the current high transmission rates, it’s a good practice to wear a mask when indoors or in large gatherings, said Rivera. 

The latest variants (BA.4 and BA.5) have shown us that outdoor transmission is possible. Outdoor transmission has always been possible, it’s just a little bit more likely now. Consider wearing a mask if you are in a crowded outdoor space like a concert or festival. 

Rivera also recommends masking around folks who are at a high risk for serious infection or immunocompromised. If you have recently done something high risk and have even minor symptoms like a tickle in your throat—mask up. 

“Wearing a mask is a responsible thing to do,” said Rivera.


Your Questions Answered

After our segment aired, many of you sent in your questions on social media. Epidemiologist Jessica Malaty Rivera shared her answers below (Updated in August 2022):

I was just diagnosed with COVID. How do I know if its BA.5?
The only way to definitively know if it’s BA.5 (or any variant for that matter) is if the sample that was collected is sent for genomic sequencing. At this point (Summer of 2022), given the prevalence of COVID-19 and the fact that BA.5 is the dominant variant, it’s safe to assume that if you are sick with COVID, it’s due to BA.5.

How do I evaluate my risk level of going to concerts and live events?
This is tricky and there’s no perfect way to measure risk. The first thing to consider is your personal risk tolerance. So I would ask yourself if you’re OK being in crowds with unmasked individuals, where testing is not being conducted, and where vaccine verification is not required? For some, the answers to those questions dictate their decision to attend certain events. There are tools like: https://covid19risk.biosci.gatech.edu/ which use available jurisdictional data to determine the likelihood of being in the same place as someone infected with COVID. Otherwise, I’d be monitoring case counts (which are underreported) and hospitalization trends (more real time).

Since these variants are so transmissible, is masking in crowded spaces (schools, businesses, etc..) going to be very effective?
Yes, masking–with high-quality masks (N95, KN95, KF94) –is still very effective in reducing the risk of transmission, especially in crowded spaces.

Is it possible to test for monkeypox in residential wastewater in the same way testing for COVID helped us to “see” outbreak clusters in advance of testing?
This is a great question and it’s currently being investigated! In fact, the virus has already been detected in wastewater sources around the country.

Is it true that lab experiments found that the BA.4 and BA.5 Omicron subvariants are over 4 times more resistant to mRNA vaccines than earlier strains of Omicron?
As of July 2022, there’s still a lot we don’t know about why these subvariants are more infectious. Some theories include immune evasion (vaccine and infection immunity). That said, it’s important to remember the primary goals of the vaccine: to prevent severe illness, hospitalization, and deaths. And the vaccines are still doing an excellent job doing that. Prevention of infection requires layers of protection: masking, distancing, vaccination, proper quarantine, and isolation, etc.

How long should you wait after having COVID to get the second booster?
The only requirement is that you be fully recovered (out of isolation) and symptom-free. Given the risk of reinfection and how prevalent BA.5 is this summer (July 2022)–I would not wait longer than that to get boosted.

You talked about how to use PCR and rapid tests. Are antibody tests still useful?
Great question. Antibody tests should be looked at as “rearview mirrors”–they can only tell us about *some* things in the past and they should not be used to gauge current or future immunity/ protection. Immunity is much more layered than antibody levels–it includes T cells and B cells etc. Immunity is also highly variable from person to person so there is no magic number to be checking form. Antibody tests cannot distinguish between antibodies from infection or vaccination. You’d have to get a specific test–one that is checking for antibodies for the nucleocapsid proteins (not the spike proteins) even to see if you have antibodies from an infection.

Do the boosters/shots lower your chances of developing long COVID?
Preventing infection and severe illness are the best ways we can reduce our risk of long-COVID (PASC). There are still so many unknowns about the condition which is why avoiding the disease is still the “best” protection.


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Segment Guests

Katelyn Jetelina

Katelyn Jetelina is an adjunct professor in the UTHealth School of Public Health, and author of the Your Local Epidemiologist newsletter.

Jessica Malaty Rivera

Jessica Malaty Rivera is an epidemiology fellow at Boston Children’s Hospital and a senior advisor at the Pandemic Prevention Institute in San Francisco, California.

Segment Transcript

IRA FLATOW: This is Science Friday. I’m Ira Flatow. I’m really eager to do this update on COVID for many reasons, but mostly because COVID is surging in the US again, and it’s raising so many questions. The latest subvariants BA.4 and BA.5 are now dominant, and things are feeling a little different during this surge, don’t you think?

I mean, people who recently got COVID are getting reinfected. The variants appear to be really contagious, and those who have so far evaded the virus are getting it for the first time. What about the boosters? How much should we rely on a new booster slated to roll out in the fall to boost our immunity against the virus?

Dr. Anthony Fauci says don’t wait for the new ones this fall. Get vaccinated now. But will they be ready for when my booster runs out in October? And masks. Should we all be masking up again indoors? Joining me to help us debunk the latest COVID misinformation and update us on the current state of COVID are my guests, Katelyn Jetelina, adjunct professor at UTHealth School of Public Health and author of “Your Local Epidemiologist Newsletter.”

She’s based in San Diego, California, and Jessica Malaty Rivera, epidemiology fellow at Boston Children’s Hospital, senior advisor at the Pandemic Prevention Institute based in San Francisco. Jessica, welcome to Science Friday. Dr. Jetelina, welcome back.

JESSICA MALATY RIVERA: Thanks for having me.

KATELYN JETELINA: Yeah, thanks for having me.

IRA FLATOW: Jessica, let me begin with you. Break it down for me. How big a difference is there between these new variants and the original Omicron variant?

JESSICA MALATY RIVERA: There is a pretty noticeable difference. When we talk about the technicalities of where these mutations are in the spike protein, it has proven to be different enough where previous infection is not something that we can really rely on for protection of a new infection. And it is something that is a little bit confounding in the sense that we thought it would be a little bit more linear in the way that the virus is evolving and it’s having a lot of offshoots. And because of that, it is complicating things.

It is making it so that a lot of things we previously assumed on the window of time you had before you could get reinfected was longer, it’s probably not that anymore, because it is different enough. Now, it is still sars-cov-2. I don’t want folks to think that it is completely different. It is not some scary Frankenstein version of the virus, but it is definitely evolved to a place where we are now talking about more variant-specific immunizations to protect us.

IRA FLATOW: And more people, Katelyn, are getting reinfected. Why is that?

KATELYN JETELINA: Yeah, that’s right. So it looks like about 25% of new cases right now are reinfections. This virus is mutating to really skirt around our first line of defense, which is called neutralizing antibodies. Omicron keeps mutating to do this better and better and then there’s also the combination of antibodies waning over time, so this wall of defense is just getting shorter and shorter with time, and that’s expected. And then third, some people just don’t mount an immune response after a primary and typically mild infection.

And so unfortunately with more transmission, this rapidly evolving virus and a virus that did recently mutate to become less severe than Delta, we can expect and should expect sars-cov-2 reinfections.

IRA FLATOW: That’s good that you’re bringing that up, because we used to think about 90 days as the benchmark of when you can’t get reinfected. But that window is a lot shorter now, right?

JESSICA MALATY RIVERA: It is. And it’s not something that I think folks should really take as infallible or that it is absolute, right? So it has always been variable. It has been roughly 90 days in the past, but now, as Katelyn mentioned too, because of this immune evasion that we’re seeing, because of all these different variables that have affected how this virus is now transmitting in the community, it’s sometimes 30 days. It’s sometimes 60 days and sometimes it’s even less than 30 days for some unlucky folks.

IRA FLATOW: So if they get reinfected, are you more or less likely to have a severe infection the second time around?

KATELYN JETELINA: You’re less likely to have a severe infection. We’ve seen many studies that show 60% to 90% lower odds of resulting in hospitalization and death with a reinfection compared to a primary infection. But that’s not 100%. There are definitely still people that can have a severe reinfection. We are seeing that, especially if you’re unvaccinated, if you’re older, if you have comorbidities, and so that’s why I– as an epidemiologist, it’s really important to me that we continue to keep transmission down and we continue to have many layers of protect so we can try and avoid reinfections as much as possible.

IRA FLATOW: Yeah, because there are some people that say, OK, I want to jump in the pool and get infected already, right? Get it out of the way, because I’m going to get it. That’s not a good idea.

JESSICA MALATY RIVERA: It’s not. No, getting an infectious disease is not an infectious disease strategy or a public health strategy for that matter. And I think that it’s because there were some very poor comparisons in the earlier days of the pandemic that once you got it you could be protected. Once you got it plus being vaccinated you were ultra protected. And again, because of this dynamic of the virus evolving so much and so rapidly, it’s not a good strategy. Not to mention the fact that there is a very real risk of long COVID and so many unknowns related to long COVID that it’s not really the gamble that you want to make.

IRA FLATOW: I’m glad you brought that up, because there’s a lot of confusion circulating about that and about how long you remain contagious with COVID and how to find out whether you can spread it or not. I mean, we are told to keep testing at home, but some of us are getting the PCR test at a clinic because our doctor tells us to. Jessica, are they both good and equal indicators of our risk?

JESSICA MALATY RIVERA: They’re both really effective tools, but they do different things. And I think right now, and I’m a bit surprised two plus years into the pandemic where I’m still seeing even coming from some medical professionals confusion about how to use the PCR test and when to use a PCR test and when not to compare it to antigen testing. We know that PCR tests are incredibly sensitive and specific, and they are excellent tools for determining detectable virus in your body. But if you are recovered, it’s very likely that you could be testing positive on PCR for several weeks, even a couple of months because it is so sensitive it’s detecting even those fragments of the genetic material of sars-cov-2.

On the flip side, antigen tests are not a perfect proxy for determining infectiousness, but they are a really good indicator of active infection. You’ve probably seen folks on Twitter talking about if you have a really dark second line on your antigen test, odds are you have a lot of virus and you should be isolating in that time. Antigen tests are very specific, and they are going to detect active virus. They’re going to detect the spike protein on the virus.

And so to me, I think that if you’re still testing positive on antigen test, not PCR, it’s a good sign that you should still be in isolation and keeping away from others.

IRA FLATOW: And Dr. Jetelina, do you agree? Should people be testing before determining if they should leave quarantine?

KATELYN JETELINA: Absolutely. And at-home antigen testing is one of the best tools we have right now to break transmission chains. I think that there’s a little difficulty with antigen tests specifically at the front end of infection. This is when we see false negatives more common, especially with Omicron. And so when we’re surging like we are right now, if someone has any symptoms, I just wouldn’t trust a negative test right now.

I would always assume that you have COVID 19 and to retest in about 24 to 48 hours, because it will likely turn positive. Now, antigen tests are really good at telling us when we’re not infectious anymore because we have very few false positives. So if you find a positive and then you get a negative after that, I would trust that a lot and trust it to leave isolation only once that antigen test is negative. We see pretty strong evidence that an Omicron infection lasts, on average, about 8 to 10 days.

Now, some people will be infectious for less, some will be infectious for more, and you really won’t know unless you test.

IRA FLATOW: That’s interesting because the CDCs current quarantine guidelines are to isolate for five days after the onset of symptoms then wear a mask around other people for five days. You’re saying that’s not enough?

JESSICA MALATY RIVERA: It’s not enough, and I think Katelyn and I have both gone on the record very publicly to talk about how misguided that recommendation is, mostly because we know that it was actually based on Delta data and not Omicron, which is when they actually issued it. I have yet to meet a person who is asymptomatic and negative within five days in an Omicron infection. It’s allergy season, there’s other colds. People are getting confused about those negative tests early on, but they may actually be positive, and so these false negatives are a big concern if people are just counting down this rigid day of, oh, I only need to stay home for five days and then I can just wear a mask.

If you have any symptoms and if you are testing positive, that is a really good sign that you are infectious and that you should be staying home until you test negative and until you are asymptomatic. I think there was a lot of confusion too about is it asymptomatic, is it resolving symptoms? To ask people to interpret resolving is very, very difficult. And I think that opens a huge can of worms and causes way too much gray for people to be making decisions on something like infectiousness.

IRA FLATOW: So keep testing is what you’re saying?

JESSICA MALATY RIVERA: Definitely keep testing.

KATELYN JETELINA: And I will say, Ira. I agree with Jessica, I do not like that CDC guidance at all, but because that CDC guidance is there, some people just can’t stay in isolation that long because they need to go to work or their employers won’t allow them a longer isolation because that’s what the CDC says. And so if someone does have to leave isolation after five days and they’re still testing positive, which there’s a really good chance that there is, they really need to wear a good mask, one that’s well fit, one that’s filtered, and everywhere once they leave isolation until they test negative again.

IRA FLATOW: I’m glad you brought that up. It’s a good segue to talk about masking up, because I see that people are not masking up, and I see the new recommendations coming out that we should be masking up in closed places indoors with other people. Do you agree, Jessica?

JESSICA MALATY RIVERA: I do. I mean, I always caveat my recommendations on these personal mitigation efforts with the fact that my risk tolerance is very, very low and is probably lower than the average person. I have young children at home. I don’t want to get COVID. That said, I still think that wearing a mask is a very simple task, and at this point with high transmission, it seems like a really good practice for folks to be wearing high quality masks when indoors, when in large gatherings.

I think these variants BA.4 and BA.5 have also shown us that outdoor transmission is possible. Outdoor transmission has always been possible, it’s just a little bit more possible now. Now, obviously, things outdoors are safer and I’m still doing things outdoors even unmasked depending on the crowds, but I think masking in high risk settings especially indoors in traveling when you’re around folks who are immunocompromised or high risk or if you’ve yourself done something very high risk or you feel a tickle in your throat. Wearing a mask is a responsible thing to do.

IRA FLATOW: Yeah. Yeah, I’m getting looked at, but I don’t care when I have my mask on. Katelyn, we talked about how BA.5 is better at circumventing our immunity, either from prior infection or from vaccines. And this week the Biden administration announced that they are planning to ask for approval for people under 50 to be able to get a second booster. Would that do anything to blunt the current wave?

KATELYN JETELINA: So boosters, especially very recently they do prevent infection. I think there’s a lot of misinformation that they don’t, and the reason that boosters do that is because they really ramp up neutralizing antibodies. Unfortunately, like I said before, these antibodies wane, but those neutralizing antibodies are effective in reducing infection. And if you don’t get infected, then you can’t transmit it. I think it’s also really important, though, that we start walking away that the purpose of vaccines is not to prevent infection.

The purpose of vaccines is to prevent severe disease and death. And what we’re seeing with a second booster, especially among adults over age 50 is that it broadens protection. That those people with two booster doses have about four times lower risk of dying from COVID-19 compared to those that just received one booster dose. Certainly, if you’re over the age of 50, go get your second booster now. Don’t delay.

Don’t wait for that Omicron booster. Also, if you’re under 50 and have multiple comorbidities or even work at a high exposure occupation, I think it makes a lot of sense to get that second booster now.

IRA FLATOW: So when you say don’t wait for that Omicron booster coming out in the fall, what about people whose boosters are running out by the fall? It’ll be six months– four, five, six months by the time that booster comes around.

JESSICA MALATY RIVERA: The number of people who have even received their booster is not very high, which is a bit discouraging. We have less than 50% of the eligible population in the US that has received a booster dose. So it’s certainly not harmful for folks to get a second booster if it becomes available. My concern is it’s similar to what Katelyn said, we have this tendency to look at vaccines as a silver bullet. That it somehow trumps all the other mitigation, but mitigation has to be layered.

It has to be all the things we’re talking about, masking, distancing, isolation, testing. We can create this false expectation that these next boosters are going to somehow be even more comprehensive than they are, but really, what it’s going to do is just buy a little bit more time from maybe an infection or severe illness, but it’s really not going to necessarily stop the pandemic.

IRA FLATOW: This is Science Friday from WNYC Studios. Speaking of new boosters, could we see an entirely new variant, like the original Omicron, that comes from an entirely different lineage and therefore this booster won’t really help?

KATELYN JETELINA: So there is the possibility of an Omicron-like event. A variant coming out of the blue that really changes the game. The last estimate I saw was that we have about a 30% chance of that happening within the year, so it’s not zero, but it’s not 100% chance. We expect and hypothesize that Omicron will continue to mutate into these ladder-like mutations.

And so I expect that even once we have this Omicron booster rollout in October, there’s already going to be a new Omicron variant taking hold, but that’s OK. The purpose of boosters and variant-specific boosters is not to chase the variant. We’re never going to win that rat race. The purpose of it is to broaden our protection, and no matter what Omicron variant is circulating, an Omicron-specific booster this fall will no doubt help against that.

IRA FLATOW: Do you expect that all of us sooner or later are going to get infected?


KATELYN JETELINA: Yeah, I remember back in March of 2020, Fauci said that he expects by the time this is done 80% of people will get infected. At the time, I didn’t believe it, but now, absolutely. I think that it’s going to become part of our lives. We have to put sars-cov-2 in this repertoire of what we encounter if we want to balance that with our quality of life, and I think it’s going to happen.

All we can try and do is to reduce that viral load as much as possible by using a lot of these layers and mitigation. So hopefully, we help our immune system along the way to fight it as quickly as possible.

IRA FLATOW: Well, both of you have certainly helped answer my questions and I hope our listeners questions to this has been very, very enlightening, and thank you both for taking time to be with us today.

JESSICA MALATY RIVERA: Thank you so much.

KATELYN JETELINA: Yeah, thanks for having me.

IRA FLATOW: Dr. Katelyn Jetelina, adjunct professor at UTHealth School of Public Health and author of “Your Local Epidemiologists Newsletter” based in San Diego, and Jessica Malaty Rivera, epidemiology fellow at Boston Children’s Hospital, senior advisor at the Pandemic Prevention Institute based in San Francisco, California.

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