A doctor answers questions on vaccines for kids, natural immunity, omicron symptoms

On Tuesday, Pfizer and BioNTech applied for emergency use authorization from the Food and Drug Administration of their COVID-19 vaccine for the littlest Americans, 5 years old and younger.

Meanwhile, there are nationwide shortages of the drugs being used to treat COVID-19 as a sister variant of omicron has emerged.

The pandemic isn't over. Dr. Melanie Swift, co-chair of Mayo Clinic's COVID-19 Vaccine Allocation and Distribution Work Group, returned to answer more listener questions about COVID-19 with host Cathy Wurzer.

The following is a transcript of the interview, lightly edited for clarity. Listen to the full conversation with the audio player above.

Let's begin by talking about this vaccine for little kids. Clinical trials in the fall of 2021 were not promising in kids ages 2-5. What's changed?

Manufacturers continue to adjust dosing. We know children require smaller doses. It's a balancing act of getting the most effective dose that minimizes side effects in kids.

I haven't seen the paperwork from Pfizer yet. If they're submitting it to [the] FDA, that's a good sign that they found the right mix.

How important is it to vaccinate the [youngest] among us?

I think it's going to be increasingly important over time. We know that the youngest children do tend to have milder illness [from COVID-19] — it may go unrecognized — but they're efficient at spreading germs for COVID as well as for many other things. So in order to reduce transmission as this pandemic continues to simmer along, I think that we're going to have to get robust vaccination all the way down to our youngest folks.

Uptake among older kids hasn't been that robust. Do we expect anything different with the youngest kids?

I don't know that we're going to see difference in uptake, especially while it's under an emergency use authorization. We know that in focus groups and surveys of parents, the emergency use authorization gives many of them pause. It is a robust process to assess for safety. The reason for emergency use is generally limited duration of effectiveness that we've been able to observe after vaccination.

I do hope that the experience in children 5 and up, which has been positive, will help those parents, particularly those who have vaccinated older kids, feel comfortable getting their younger ones vaccinated. I recognize we're going to continue to have some challenges with uptake until we get a full authorization from the FDA, most likely.

Question from Melonae on Facebook: Do you anticipate boosters [will be recommended] for the 5-to-11 age group?

I think it's likely that the waning of immunity that we see in older individuals will also be seen in kids. They got very good immune responses to the initial doses, but we do expect that to wane — just as we do for many, many vaccines for which you get a childhood initial series and then later boosters. So I think it's very likely we'll see [boosters recommended for kids] as well.

Because of the booster shots, I'm wondering: What does it mean to be fully vaccinated now? For some, it's having the fourth shot.

The terminology has really changed with what we've learned about waning immunity and the boosters. It used to be that after your initial series was completed and you waited two weeks, you were considered fully vaccinated.

What we now know is that that vaccine, that mediated immunity, is really good, but it's not forever. After some period of time, six months or so, your protection from infection from that initial vaccine really wanes. You still have some protection that's good against hospitalization and severe disease, but you need a booster to maintain your protection against getting infected.

So now, rather than “fully vaccinated,” [the terminology] is really “having your vaccinations up to date.” And that's really the target now: having your vaccines up to date such that if you're due for a booster you've had it.

Do you think this change in language will help people become more comfortable with vaccination?

I hope so. It's similar to the language we use for other diseases that we vaccinate for, like measles: “Are your vaccines up to date?” You take boosters for that, for tetanus, etc. Part of the shift in language, I think, in a subtle way will help people feel that this is a more normal part of life.

There's a bill in the Minnesota Legislature that would allow for vaccine mandate exemptions for workers who have so-called ‘natural immunity’ because of a previous COVID-19 infection. How robust is natural immunity after an infection?

It differs by variant. We have seen that there's some protection from prior infection with omicron — but [it’s] not long-lasting. And [with] earlier variants, the protection from earlier infection [is] not as robust as the vaccine protection and also wears off after 90 days or so.

So we really don't yet know the duration of natural immunity, but we think it's going to be 90 days or so. And we don't have a good lab test that will tell us that you still are immune from your previous infection. There are antibody tests available, but they don't tell us how well those antibodies work.

Question from Kay on Instagram: How soon can you get infected with COVID again after having it?

We've traditionally said 90 days. However, we've seen people who got delta in the fall and then got omicron less than 90 days later.

I would say from what we're seeing, for the first six weeks or so [after a COVID infection] — about 45 days — it is highly unusual to get a second infection. So people can feel that they're really protected from infection for about a month and a half. After that, it depends upon the variant, and you may still be able to get infected within 90 days. But after 90 days, it does become more likely that you get reinfected.

Question from Chris on Facebook: I have started to feel frustrated and tired. I have four children, three of whom have been vaccinated. Now their school is allowing kids to go mask-less. What are the dangers for my family? Is it worth continuing to mask? And how is this different from any other sickness my kids could get?

Boy, that pandemic fatigue just comes through loud and clear, doesn't it? It's especially difficult, I think, for families with a mix of vaccinated [kids] and kids that are too young to be vaccinated, going to school and not being able to control the risks that your children get exposed to.

Vaccinating your kids and having them wear their own mask [are] still the thing[s] you have the most control over — also, teaching them how to social distance from other kids who might not be masked. You can't control the behavior of other kids.

As far as the dangers to your family, we do know that children tend to have milder cases of COVID when they get it, but it still is different from other endemic diseases. There are rare but very serious conditions that children [can] get [when they contract COVID-19]. The most concerning of those is multisystem inflammatory syndrome. Less than 0.03 percent of kids [who contract COVID-19] will get this, but it's very, very serious. It has caused pediatric deaths and hospitalization in the ICU.

So although it is rare, it's a roll of the dice, really — you can't really predict which kid’s going to get this very serious COVID complication. So, still worth taking those protections.

Question from Sanjay on Instagram: Is overproduction of mucus, especially around the throat area, a symptom of COVID?

No, I haven't really seen that. Symptoms of COVID are fever, cough, sore throat — some people do have congestion with it. But not an overproduction of mucus, no.

Question from a listener: Am I going to lose my sense of taste and smell [from an] omicron [infection], or is that [just] delta?

[That was a symptom of] all of the prior variants. Interestingly — and this is still anecdotal information that we are compiling and observing — there are some different presentations that we've seen in omicron.

One is kind of a milder cold-like syndrome, very much like earlier variants but a little bit milder and often without that loss of taste and smell that was really characteristic of COVID before omicron. Another presentation that we're seeing is more of a gastrointestinal illness — and some of those patients actually don't have any respiratory symptoms at all.

Michael on Twitter shares a heartfelt thanks to all the people that work at Mayo under very difficult COVID conditions. Question from Michael: When will Evusheld be available for immunocompromised people in wider quantities?

First of all, thank you. I share your admiration for the health care workers at Mayo — and across the state and across the country in hospitals and long-term care everywhere. They really have been fighting a marathon and they need our support.

Evusheld is a monoclonal antibody that's made by AstraZeneca and, like all monoclonal antibodies, had [previously] been used for people who were at high risk of COVID complications. Unfortunately, Evusheld is not active against omicron, so it is not being used right now.

Sotrovimab is the name of the one monoclonal antibody we have in our arsenal that is effective against omicron. It’s in short supply, and it is being limited to people who are at very high risk.

There are some other tools in the arsenal: The antiviral drugs Paxlovid and remdesivir continue to be useful [against] omicron. Everything still is, of course, in limited quantity and prioritized for those highest-risk people. So while immunocompromised patients may not get Evusheld, that's okay because it doesn't really work against omicron. They have access to other helpful treatments to keep them from landing in the hospital.

Question from a listener: I am an older adult with Type 2 diabetes and heart disease, and I'm a cancer survivor. When will I ever get my life back? I'm afraid of getting COVID.

This is the theme that we're hearing: When is this going to end? And when can we start to return to normal? Of course, people with diabetes and heart disease are at higher risk. And previous cancer, depending upon the type of cancer and the treatment for it, may also put you at high risk for complications.

[Again,] getting vaccinated and taking your booster — being up to date on your vaccines — is very, very important because even in people with those high-risk conditions, those are the things that help prevent serious disease. You might get COVID, but vaccination really helps prevent serious cases that would land you in the hospital.

Question from Brad: What are some small steps a person can take to assist in the shift in mindset [if COVID-19 becomes] endemic?

All of these questions, I think, have had this the theme in common. Aside from your personal behaviors, as we've mentioned — being vaccinated, wearing masks where indicated — individuals can really help counter misinformation that is pretty prevalent out there and dial down the temperature of conversations.

We're going to enter a phase where we periodically have local and regional flares or surges. There will be masking requirements that come and go; there will be changes to vaccine[s] and vaccine guidance. What ordinary individuals can do is really listen to trusted authorities and help their friends and family accept the advice and not see every local task ordinance as some unreasonable government overreach.

We're going to have to all accept that there will be times we need to modify our individual behavior to keep everyone as safe as possible. So look for trusted sources of information, and try to counter misinformation gently and respectfully when you find find it.

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