How to Decide When to Get Your Young Child Vaccinated

Parents can choose between the Pfizer-BioNTech and Moderna vaccines for kids under 5

doctor putting bandaid on young child's arm after receiving vaccination Photo: Getty Images

Coronavirus vaccines are now available for children under 5 years of age in the U.S. Parents can choose between a low-dose version of the Moderna vaccine, authorized for kids ages 6 months to 5 years old, and a very low-dose version of the Pfizer-BioNTech vaccine, authorized for kids ages 6 months to 4 years old. (A higher-dose version of the Pfizer vaccine is already available for kids 5 and up.)

For many parents, finally having access to vaccines for young children is a relief. Kids ages 5 and older have been able to get vaccinated since October 2021. Yet some parents may still have questions, or may be taking a wait-and-see approach.

After an initial burst of enthusiasm in vaccinating older kids, there was a drop-off. By the end of January, a few months after COVID-19 vaccines were first authorized for 5- to 11-year-olds, more than 31 percent of kids in that age group had received at least their first shot. Yet by mid-June, not much had changed: Only about 36 percent of kids in that age group had gotten one shot, and just 29.5 percent were fully vaccinated. (Uptake has been better in adults: 76 percent of U.S. adults were vaccinated by then.)

Some parents may feel hesitation about getting their youngest children vaccinated. But take comfort, says Tina Tan, MD, a pediatric infectious disease specialist and professor of pediatrics at Northwestern University in Chicago: These vaccines have been thoroughly evaluated for safety in children 6 months to under 5 years old, in trials involving thousands of children. Side effects in the trials were typically mild, with no concerns raised about serious adverse events. And scientists and doctors have also learned a lot about the safety of these vaccines since versions of them have already been given to millions of older children and adults, she says.

The American Academy of Pediatrics and other experts say parents should get their children vaccinated, including their youngest children.

To help walk parents through the decision-making process, CR consulted with experts and reviewed the data on coronavirus vaccines for young kids. If you have questions about getting your child vaccinated, you should also talk to your child’s pediatrician, says Amna Husain, MD, a pediatrician based in New Jersey and spokesperson for the AAP.

Why to Get Young Kids Vaccinated

“COVID-19 vaccines are very necessary for kids under 5 years,” Tan says. “Infants under 1 year of age and children with any underlying condition are at increased risk for complications if they get infected.” 

While many children who get COVID-19 recover well, the illness can be serious for young children, and is currently the fifth leading cause of death for people ages 1 through 4, according to Matthew Daley, MD, a pediatrician and a member of the group that advises the Centers for Disease Control and Prevention on vaccines, speaking at a CDC meeting. 

Plus, children who get COVID-19 can develop MIS-C, a rare but serious condition where organs can become inflamed, leading to damage or death. Husain says kids can also get long COVID, the name for the much more common condition when symptoms related to COVID-19 hang on for months or even longer after an initial infection.

When to Get Young Kids Vaccinated

Omicron and its subvariants have increased the likelihood of infection for everyone because they are more transmissible than any previous variants, Tan says. And because they cause more upper respiratory symptoms than previous variants of the coronavirus, they’ve led to more hospitalizations for respiratory distress in infants and younger children, she says, because younger kids have smaller airways.

More on COVID-19

Because of that, experts say that parents should get their kids vaccinated quickly because that’s the best way to protect them against severe disease, and the best way to help protect vulnerable members of a household, who could catch the virus if a young child is infected. “Parents of children younger than 5 should make a plan to get their kids vaccinated as soon as possible,” Daniel McQuillen, MD, president of the Infectious Diseases Society of America, said in a statement.

Parents can choose between two vaccines for young kids (more on that below). But because it can take some time before protection fully kicks in, and there are currently extremely transmissible variants of the virus circulating, parents should try to get kids vaccinated as soon as they can—rather than trying to game it out and waiting for the start of school or another surge, for example. If young kids are vaccinated with Moderna, it takes six weeks before they are considered fully vaccinated. It they are vaccinated with Pfizer-BioNTech vaccine, it will be 13 weeks before they’re considered fully vaccinated.

If your child has already had COVID-19, the guidance is basically the same—the CDC says kids who have had COVID-19 should still get vaccinated. When earlier variants such as delta were more prevalent, prior infection provided better protection. At that time, the CDC said parents could wait for up to three months after a positive test for their kids to get their first shot, or the next in their immunization series. But omicron has changed the situation. It seems better able to evade protection offered by prior infections, and may offer less protection against future exposures.

Tan says parents shouldn’t wait to get kids vaccinated now, even if they’ve been previously infected. Kids can get a shot as soon as they’ve completed required isolation after infection, according to the CDC.

Comparing the Two Options

Dose and Schedule

The Moderna vaccine authorized for young children consists of two vaccine doses, each containing 25 micrograms of vaccine, given four weeks apart. (Adults get 100-mcg doses for their first two shots, and 50-mcg booster doses. The Moderna vaccine has not yet been authorized for older kids.) 

The Pfizer-BioNTech vaccine for the youngest kids consists of three doses, each containing 3 mcg of vaccine. The second dose is given three weeks after the first, and the third dose eight weeks after the second. (Adults and adolescents 12 and older get 30-mcg doses for their first two shots and for their boosters. Kids ages 5 to 11 get 10-mcg doses.)

Efficacy

It’s not yet possible to say which of these options offers more effective protection against infection in young kids.

An early analysis of trial data found the Pfizer-BioNTech vaccine to be about 80 percent effective at preventing infection after three doses, but there were so few cases of COVID-19 in the trial that that number might not be reflective of real-world efficacy. And according to experts who spoke at the Food and Drug Administration meeting on authorizing the vaccines, there’s not necessarily any significant protection after just the first two doses, making the third shot absolutely necessary—an added logistical challenge for parents. 

There’s more definitive efficacy data on the Moderna vaccine, though it is still preliminary and could vary in real-world settings. For kids ages 2 through 5, the two doses appeared to be between 36.8 and 46.4 percent effective at preventing infection, and they appeared to be about 53.5 percent effective at preventing infection in kids under 2. 

In both cases, completing the series of vaccines raised protective antibody levels to the point that they were comparable to the levels considered protective in adolescents and adults.

But more important than protection against infection is the protection these vaccines offer against more serious illness, according to Tan. “The COVID-19 vaccines are very effective at preventing severe COVID-19 disease, hospitalizations, and deaths in all age groups,” she says. “Protecting their child is the most important goal, so parents should receive whichever vaccine their pediatrician has in stock.”

Side Effects

Data presented at a meeting of the FDA vaccine advisory panel indicated that side effects from both vaccines were generally similar to those of other childhood vaccines, including pain at the injection site, headache, fatigue, and fever. The Moderna vaccine had slightly higher rates of some of these side effects, though the vaccines were still comparable.

“I recommend discussing with your pediatrician what options are available and what they recommend for your child,” Husain says. In many cases, especially since these vaccines are so new, a location may have only one option.

More rare side effects like heart inflammation—myocarditis and pericarditis—were not seen in vaccine trials, though they might not have been large enough to capture such a rare effect, which occurred in about 71 cases per million male 12- to 15-year-olds vaccinated, and about 106 cases per million male 16- and 17-year-olds. While adolescent males had elevated rates of heart inflammation after their shots, many experts expect this to be less of an issue for younger kids because the risk for the condition in general appears to be highest in males after going through puberty. In kids ages 5 to 11, there has been so far about 1 reported case per million shots given. Plus, getting COVID-19 itself is associated with a much higher risk for myocarditis than the vaccine, even among the adolescent males at the highest risk for this side effect.

Getting the Actual Shot

To see where vaccines are being offered near you, you can check Vaccines.gov. But it’s worth checking with your child’s pediatrician first to see whether they have shots available. In addition to pediatric offices, shots for young children are being offered at pharmacies, local health department sites, and various vaccine clinics, though some of these sites may offer vaccines only to kids 2 or 3 and older. 

It’s worth talking to your kids about why it’s important for them to get vaccinated by explaining how vaccines protect them as well as their family and community, Husain says. The CDC also offers tips for supporting your child before, during, and after any vaccine shots.

“The most important thing is to be calm and honest when discussing receiving a vaccine to make the experience less stressful,” Tan says. “Also, distraction can play a big role in helping to calm a child down when receiving the vaccine.”

After the shot, you can apply heat or ice, and give your child Tylenol or Motrin, Husain says.

“It is fantastic that we are now able to vaccinate infants and children under 5 years of age,” Tan says. “However, we also need to work on increasing vaccination rates in the 5- to 11-year and 12- to 17-year population in order to provide the best protection. COVID-19 is here to stay, and getting vaccinated is the best way to protect yourself and your family against this virus.”


Head shot image of CRO Health editor Kevin Loria

Kevin Loria

I'm a science journalist who writes about health for Consumer Reports. I'm interested in finding the ways that people can transform their health for the better and in calling out the systems, companies, and policies that expose patients to unnecessary harm. As a dad, I spend most of my free time trying to keep up with a toddler, but I also enjoy exploring the outdoors whenever possible. Follow me on Twitter (@kevloria).