Children under 5 are now eligible for the COVID-19 vaccine. Here's what parents should know.

COVID-19 vaccines for the youngest Americans are finally here. On Saturday, Centers for Disease Control and Prevention Director Rochelle Walensky signed off on the shots for children between the ages of 6 months and 5 years, and vaccinations for that age group began Tuesday across the United States.

Walensky’s decision came after the CDC’s Advisory Committee on Immunization Practices voted to approve the COVID vaccines for children under 5, and just one day after the Food and Drug Administration had announced it was authorizing the shots under emergency use for that age group. The decision, one that many parents had been waiting for, expanded eligibility for COVID vaccination to nearly 20 million additional children, according to the CDC.

“The United States is now the first country in the world to offer safe and effective COVID-19 vaccines for children as young as 6 months old. For the first time in our fight against this pandemic, nearly every American can have access to lifesaving vaccines,” President Biden said on Tuesday from the White House.

To help offer guidance for parents of young children now eligible to receive the COVID vaccine, Yahoo News spoke to Dr. Leana Wen, public health professor at George Washington University and the author of “Lifelines: A Doctor’s Journey in the Fight for Public Health.”

Which of the COVID-19 vaccines are available for the youngest children, and how many doses are recommended?

Both the Pfizer and Moderna vaccines have now been authorized by the FDA and recommended by the CDC for children under 5, Wen said, but the dosage and the number of doses recommended to achieve maximum protection against COVID are different.

The Moderna shot consists of two doses, given four weeks apart, while Pfizer’s is administered as a three-shot regimen, with the first two doses given three weeks apart, followed by the third shot given at least eight weeks after the second.

Each dose of the Pfizer vaccine, Wen explained, is 3 micrograms, which is one-tenth of the adult dose. For the Moderna vaccine, “the dosage is 25 micrograms [per dose], which is one-quarter of the adult primary series,” Wen said.

Are the vaccines safe and effective for young children?

“Both vaccines, in their formulations, so three doses of Pfizer’s and two doses of Moderna’s, have been found to be safe and effective,” Wen said.

In clinical trials, among children 6 to 23 months old, two doses of the Moderna vaccine were found to be 31% to 51% effective against disease, according to Katelyn Jetelina, an epidemiologist and author of a newsletter called “Your Local Epidemiologist.” For kids 2 to 5 years of age, a 37% to 46% efficacy against disease was observed after the two Moderna doses, she wrote in her newsletter.

Pfizer, on the other hand, reported 80.3% efficacy against disease in children 6 months to 5 years old after three doses.

“The great news is that both Pfizer and the Moderna vaccines are safe,” Wen said. “There are no new adverse effects that were seen, and they both are very effective. They produce a strong antibody response that is on par with the antibody response seen in older adolescents and in adults. Basically in other age groups,” she added.

What are the side effects and how can parents treat them?

Wen said the side effects seen during clinical trials were minimal but that there are two types of reactions that can be expected that are similar to those seen in adults. “One is local and the other is systemic,” she said.

“The local reactions would include soreness and redness at the injection site. That’s something seen with really all vaccines, and so it should not be something new to parents,” Wen said. “The other systemic reactions would include things like fever, fatigue, overall just not feeling well and some crankiness,” she added.

Wen said parents should know these reactions are expected and are normal. She recommends that parents follow CDC guidance and avoid giving pain medications to their children before receiving the vaccine to prevent these reactions. However, she says that after vaccination it is OK to give certain medication to manage these symptoms.

“If your child does develop a fever, then it’s fine. It’s perfectly fine to give them Tylenol or ibuprofen,” she said, adding that parents should make sure they are giving their child the dosage that’s appropriate for their age and their weight.

Why should parents vaccinate their children against COVID-19?

Even though children are less likely than adults to become seriously ill from the coronavirus, health experts say they are still vulnerable to disease and complications. According to the FDA, 442 children aged 0-4 years old have died from COVID since the start of the pandemic.

COVID-19 hospitalizations of children under 5 also increased during the first Omicron wave, according to the CDC. Of those in this age group who needed hospitalization, 1 in 4 required ICU admission.

In addition, more than 8,500 children have suffered a condition called multisystem inflammatory syndrome (MIS-C), which can cause inflammation of the heart, lungs, kidneys, brain, eyes and other organs, according to the agency.

Should parents vaccinate their children if they’ve already had COVID?

More than 13.6 million children have tested positive for the virus since the beginning of the pandemic, according to the American Academy of Pediatrics. Even though getting COVID-19 may result in some level of protection, the CDC recommends that parents vaccinate their children regardless of prior infection.

“The reason is that vaccination, in addition to recovery from infection, provides a higher and more consistent level of protection than just infection alone,” Wen said. “That hybrid immunity conveys a high level of protection,” she added.

However, the CDC says that if a child has been infected with COVID, their next dose can be delayed three months from the onset of symptoms or from the date they received a positive test if they had no symptoms.

“That’s because the chance of reinfection is low in that three-month period, and so they could choose to wait, but they should not defer the vaccine altogether,” Wen said.

How should parents decide which vaccine to give their children?

“I think that there is not a wrong choice here,” Wen said, adding that some pediatricians’ offices may not have both options and many parents will choose the vaccine that is available to them.

Some parents may prefer the Moderna shot, Wen said, because it is only two doses compared to Pfizer’s three. “If parents start getting their kids vaccinated now, they’ll be fully vaccinated by the time of the next school year,” she said. “Other parents will say that there is a record with the Pfizer vaccine. The Pfizer vaccine has been authorized for months and has been given to millions of 5-to-11-year-olds, and they might feel more comfortable with the Pfizer vaccine for that reason,” she noted.

Where can parents access the vaccine for their young children?

Earlier this month the Biden administration outlined a plan to offer the COVID-19 vaccine to children under 5 and said that they could get vaccinated at pediatricians’ offices as well as children’s hospitals, select pharmacies and public health clinics across the country. The Biden administration also said it has already made 10 million doses available to states and health providers and that roughly 85% of children younger than 5 live within 5 miles of a vaccination site.

“I would recommend for parents to call your pediatrician’s office first,” Wen said, adding that some pharmacies may not have the vaccine available for this age group.

“Other resources include your local county health department and state health department that might also have local resources and might even be setting up vaccination clinics in your community,” she said.