COVID vaccines in children under 5: Pediatricians answer parents' most common questions

For parents who waited months for COVID vaccines to be approved for children under 5, the wait is finally over: After the Centers for Disease Control and Prevention (CDC) endorsed the use of Pfizer-BioNTech’s and Moderna’s COVID vaccines for children as young as 6 months old on Saturday, vaccinations for the youngest age group are now slowly rolling out across the country.

But many parents have questions about giving their young children the vaccine — from how far apart the shots need to be spaced to questions about efficacy and side effects and even whether their kid needs the shots if they, like 75% of children in the U.S., have already been infected.

So Yahoo Life reached out to pediatricians to help answer some of the most common questions parents have about the vaccine for children under 5:

For children who have already gotten COVID — particularly if they were exposed to the most recent variant — do they still need to get the vaccine?

Yes, say experts, including the CDC. “It is absolutely worth getting vaccinated,” Dr. Catherine Mary Healy, associate professor of pediatrics-infectious diseases at Baylor College of Medicine, tells Yahoo Life. “Although it is true that children who have gotten COVID may be protected from infection for some months afterward, we don’t know for certain how long that protection lasts or how effective it will be against new variants.”

While there is protection from natural immunity, Dr. Alok Patel, pediatric hospitalist at Stanford Children’s Health, tells Yahoo Life, “it is hard to tell just how durable and protective it is, over time — it varies by the individual. The primary vaccine series is highly protective against severe illness and/or death.”

As Dr. Purva Grover, medical director for pediatric emergency services at Cleveland Clinic and part of its COVID-19 vaccine distribution committee, tells Yahoo Life: “An infection will not replace the vaccine.”

Healy also points out that studies show vaccination after infection “enhances protection against reinfection and against serious illness.” She explains that “ensuring children are protected is important as we learn more about some of the short and long-term effects of COVID-19 infection, even if some of these conditions” — like MIS-C (multisystem inflammatory syndrome) — “are uncommon or rare.” MIS-C is a rare condition that can show up one to two months after natural infection, including sometimes after an asymptomatic infection, explains Healy.

How long after a child’s COVID infection should parents wait before getting the vaccine?

Experts suggest talking with your child’s pediatrician to determine the best timing for getting your child vaccinated after a COVID infection. That’s because the situation can vary based on a child’s medical history, including their personal or family risk of severe disease should reinfection occur, along with the rates of infection in their community.

That said, “many scientists and physicians recommend waiting a couple of weeks, at least until all symptoms have resolved,” Patel notes. “If a child received monoclonal antibodies during treatment for a COVID infection, it’s recommended to wait 90 days prior to receiving a vaccine.”

In general, the CDC states that COVID vaccination “should be deferred until a person has recovered from their illness and the isolation period has ended,” says Healy. However, she points out that parents may consider deferring vaccination until three months after infection, “since we know that natural infection gives protection for weeks to months and chances for reinfection are low during that time.”

How spread out do the shots need to be?

With Pfizer’s three-dose vaccine for children 6 months to 4 years old, the first two doses are given at least three weeks and up to eight weeks apart, followed by a third dose at least eight weeks after the second shot.

For the Moderna two-dose vaccine for children 6 months through 5 years old, the first dose and second dose are given at least four weeks and up to eight weeks apart.

How long does it take for a child under 5 to be fully vaccinated after completing all of the shots?

A child is considered fully immunized two weeks after completing the last recommended shot, notes Grover. “This is because it takes 10 to 14 days for the immune response to be at its maximum level,” Healy explains. “This doesn’t mean that there is no response before 14 days after the shot, simply that it’s not at the maximum level.”

Given that there are two weeks before the shots are fully protective, Patel suggests that “parents should keep this timing in mind when planning trips, summer camp or a return to school in fall.”

What side effects can parents expect from the vaccines?

As with most routine vaccines, the most common side effects parents can expect are pain, redness and tenderness in the limb where the shot was given. “Some children may also experience fever or tiredness and irritability, headaches or muscle aches and pains,” notes Healy. “Less commonly there may be swelling of the glands.”

Most of these side effects are mild and go away in two to three days. However, experts suggest that parents reach out to their child’s primary health care provider if they have any specific concerns about side effects from the vaccines or if your child is experiencing other symptoms such as shortness of breath. “If in your gut as a parent you don’t like the way something feels, go ahead and seek a medical opinion,” says Grover. “Never second-guess yourself.”

Any tips for easing discomfort in children during and after the shots?

Distracting your child during the shot, followed by a reward, are “always great tools,” says Patel.

Some ideas for distractions include reading to them or letting them watch a video on your smartphone. But tech-free options work well too. “Some studies have shown that simply hugging, cuddling or hand-holding after a shot can help children deal with this discomfort,” says Healy.

You can also ask your child’s pediatrician to numb the area with an ice pack to help ease immediate discomfort before administering the vaccine. After the shot, if needed, a children’s non-aspirin pain reliever or a cool, damp cloth placed where the shot was given can “work wonders for easing pain,” says Patel.

Moving the extremity after the shot also helps. “The more they move they seem to have a better recovery,” says Grover.

How effective is the vaccine in children under 5, given the dosage is lower than other age groups?

Early data suggests that Pfizer’s three-dose COVID vaccine is 80% effective in children under 5, which Grover says is “significantly higher than most other childhood vaccines we get on a yearly basis.”

Moderna's two-dose vaccine is 51% effective in preventing illness in children 6 months to 2 years old and 37% effective in children 2 to 5 years old.

“The dose is smaller for this vaccine — at 3-μg [micrograms], it’s one-tenth the adult dose — and this was carefully selected to ensure the vaccine was well tolerated for such a young population,” explains Patel.

But, as Healy points out, just because the vaccine dose is lower in children than in older age groups, “it does not follow that it is less effective, just that it is age appropriate.”

Pediatric vaccine doses are set at a certain amount “because clinical trials show that the dose chosen is safe, well-tolerated, induces a good immune response and is effective,” explains Healy. “Children get lower doses of antibiotics than adults, but the antibiotics work just as well.”

How important is it for children under 5 to get vaccinated?

Experts agree that it is “really important” that children under 5 get vaccinated. “Parents should absolutely seek to get their young children vaccinated — especially those parents of children with underlying medical conditions or who live in the same household as high-risk individuals,” says Patel.

Even though fewer children get seriously ill from COVID-19 than adults, says Healy, “some do and we cannot predict who these children are.” In addition, Healy notes that emerging evidence shows “even children without underlying health conditions can experience a wide range of new or ongoing health problems ranging from ‘mild’ (cough, fatigue, difficulties in concentration or physical activities) to the rare occurrence of MIS-C” after being infected, adding that studies in older children show that vaccination can help protect against MIS-C.

Along with protecting their own health, getting children vaccinated can help protect others. “Part of it is community transmission, including their own little community — parents, family members who are immunocompromised or immunosuppressed, people in their little bubble who will be way more protected and safe if they are vaccinated,” says Grover.

Patel agrees, saying: “Vaccines will overall reduce the risk of community spread and symptomatic illness, which, in turn, leads to a reduction of transmission to others.” In addition, it also reduces the circulation of the virus, notes Healy, “giving the virus less chance to adapt and evolve into new variants, which may be more transmissible and result in severe illness.”

How long will the vaccine be effective for?

“That’s probably a million dollar question,” says Grover, who notes that there are “ongoing studies” currently looking at how long protective antibodies last in both adults and children.

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