Coronavirus disease 2019 (COVID-19) vaccines are available to children in the U.S. Here’s what parents need to know about the safety and effectiveness of the vaccine, the possible side effects, and the benefits of getting vaccinated.

If children don’t frequently experience severe illness with COVID-19, why do they need a COVID-19 vaccine?

While rare, some children can become seriously ill with COVID-19 after getting the virus that causes COVID-19.

A COVID-19 vaccine, updated to the most common strain of the virus that causes COVID-19, might prevent your child from getting the virus that causes COVID-19. It also may prevent your child from becoming seriously ill or having to stay in the hospital due to COVID-19.

What COVID-19 vaccines are available to kids in the U.S.?

In the U.S., COVID-19 vaccines are available to children based on their age. The number of shots, also called doses, depends on the vaccine and the child’s vaccine history.

  • Pfizer-BioNTech COVID-19 vaccine. For children between ages 6 months and 4 years, three shots of the vaccine brings them up to date. The three shots may be a mix of the original, called monovalent, vaccine and the currently available vaccine called an updated or bivalent vaccine.

    After the first dose, the second shot is given at least 3 to 8 weeks later. The third shot is given at least 8 weeks after that.

    If a child has had three shots of the monovalent Pfizer-BioNTech COVID-19 vaccine, the child is eligible for one additional dose of the bivalent vaccine at least eight weeks after their last monovalent shot.

    People age 5 years and older who are unvaccinated need one shot to be considered up to date. Those who already had one dose of monovalent vaccine can get a bivalent shot at least eight weeks after the original dose.

    For people age 5 and older who have already had one dose of the bivalent vaccine, the CDC hasn’t recommended more shots.

  • Moderna COVID-19 vaccine. For children between ages 6 months and 5 years, the series is two doses. After the first dose, the second is given at least 4 to 8 weeks later.

    For kids between ages 6 months and 5 years who previously got two shots of the monovalent Moderna COVID-19 vaccine, an additional dose of the currently available bivalent vaccine is recommended. That shot can be given at least eight weeks after the second monovalent vaccine.

    For people age 6 and older one shot will bring them up to date. For people in this age group who had one shot of the monovalent vaccine, an additional dose of the bivalent vaccine is recommended. This can be given at least eight weeks after the first shot.

  • Novavax vaccine. For people age 12 and older the series is two shots of the vaccine. The second shot is recommended 3 to 8 weeks after the first shot. The CDC recommends that people who get a Novavax vaccine series also get one shot of either Moderna or Pfizer-BioNTech COVID-19 bivalent vaccine at least eight weeks after their second Novavax shot.

    • An eight-week interval between the first and second doses might be best for some people, especially males ages 12 to 39. A longer interval might give more protection against COVID-19 and lower the risk of rare heart problems, such as myocarditis and pericarditis. Also, if your child recently had COVID-19, you may talk to a health care professional about delaying vaccination by up to three months.

How did the FDA determine the safety and effectiveness of the COVID-19 vaccines for use in kids?

For children ages 5 through 11, the FDA reviewed a vaccine study of more than 4,600 children in this age range. Of this group, about 3,100 were given the Pfizer-BioNTech COVID-19 vaccine. The other children were given an inactive (placebo) shot. Children who were given the vaccine were monitored for side effects for at least two months after the second dose. Side effects were generally mild to moderate.

The FDA also took an early look at cases of COVID-19 that occurred one week after children were given a second dose of the vaccine. None of the children in this analysis had been previously diagnosed with COVID-19. Among 1,305 children given the vaccine, there were three cases of COVID-19. Among 663 children given the placebo, there were 16 cases of COVID-19. The results suggest that the vaccine is about 91% effective in preventing COVID-19 in this age group.

For children ages 12 through 15, the FDA reviewed a vaccine study of more than 2,200 U.S. children in this age range. Of this group, about half were given the Pfizer-BioNTech COVID-19 vaccine. The other children were given a placebo shot. A week after the second dose was given, there were no cases of COVID-19 in the 1,005 children given the Pfizer-BioNTech vaccine.

Among 978 children given the placebo, there were 16 cases of COVID-19. None of the children had previously been diagnosed with COVID-19. The results suggest that the vaccine is 100% effective at preventing the COVID-19 virus in this age group. Also, a portion of the children in each age group were monitored for safety for at least two months after being given the second dose of the COVID-19 vaccine.

To find out the effectiveness of the Pfizer-BioNTech vaccine for children ages 6 months through 4 and the Moderna COVID-19 vaccine for children ages 6 months through 17 years old, the FDA looked at the immune responses of children in these age groups after they were fully vaccinated.

The FDA compared those responses to the immune responses of young adults who’d been given higher doses of the same mRNA vaccine.

As with the other vaccines, side effects were recorded. Some of the children were monitored for safety for at least two months after being fully vaccinated.

To find out how well the Novavax COVID-19 vaccine worked, the FDA reviewed data on 2,232 people ages 12 to 17. The research suggests that the vaccine was about 78% effective at preventing COVID-19 disease in this age group.

What are the side effects of the COVID-19 vaccines for kids?

Children given COVID-19 vaccines have side effects similar to those faced by adults. The most commonly reported side effects include:

  • Pain, redness or swelling where the shot was given.
  • Tiredness.
  • Headache.
  • Chills.
  • Muscle pain.
  • Joint pain.
  • Swollen lymph nodes.

Children ages 6 months through 3 years old also might cry, feel sleepy or lose their appetite after vaccination.

Similar to adults, children have side effects within two days after vaccination that typically last 1 to 3 days. More children reported these side effects, except for injection site pain, after the second dose of the vaccine. However, some people have no side effects.

It isn’t recommended that you give your child a pain relief medicine before vaccination to prevent side effects. Ask your health care team about giving pain relief medicine that doesn’t contain aspirin after your child gets a COVID-19 vaccine.

Can COVID-19 vaccines affect the heart?

In some people, COVID-19 vaccines can lead to heart complications called myocarditis and pericarditis. Myocarditis is the swelling, also called inflammation, of the heart muscle. Pericarditis is the swelling, also called inflammation, of the lining outside the heart.

It’s still rare, but in the U.S., there has been an increase in reported cases of myocarditis and pericarditis after mRNA COVID-19 vaccination, particularly in males ages 12 to 39. Research also suggests that there’s a higher risk for these conditions after the Novavax COVID-19 vaccine is given.

Of the cases reported, the problem happened more often after the second dose of the COVID-19 vaccine and typically within one week of COVID-19 vaccination. Most of the people who got care felt better after receiving medicine and resting.

Symptoms to watch for include:

  • Chest pain.
  • Shortness of breath.
  • Feelings of having a fast-beating, fluttering or pounding heart.

If you or your child has any of these symptoms within a week of getting a COVID-19 vaccine, seek medical care.

If you or your child develops myocarditis or pericarditis after a dose of an mRNA COVID-19 vaccine, the CDC recommends avoiding getting another dose of any COVID-19 vaccine.

Is there any research on the long-term effects of the COVID-19 vaccines?

Because COVID-19 vaccine clinical trials only started in the summer of 2020, it’s not yet clear if the vaccines will have long-term effects. However, vaccines rarely cause long-term effects.

Some of the children in each age group were monitored for safety for at least two months after being fully vaccinated.

If you’re concerned, in the U.S., safety data on COVID-19 vaccines will be reported to a national program called the Vaccine Adverse Event Reporting System. This data is available to the public. The CDC has also created v-safe, a smartphone-based tool that allows users to report COVID-19 vaccine side effects.

If you have additional questions or concerns about your symptoms, talk to your doctor.

How do the mRNA COVID-19 vaccines work?

The Pfizer-BioNTech and the Moderna COVID-19 vaccines use messenger RNA, also called mRNA. Researchers have been studying mRNA vaccines for decades.

This type of vaccine gives your cells instructions for how to make the S protein found on the surface of the COVID-19 virus. After vaccination, your muscle cells begin making the S protein pieces and displaying them on cell surfaces. This causes your body to create antibodies. If you later become infected with the COVID-19 virus, these antibodies will fight the virus.

Once the protein pieces are made, the cells break down the instructions and get rid of them. The mRNA in the vaccine doesn’t enter the nucleus of the cell, where DNA is kept.

Is there any difference in the COVID-19 vaccines for children and adults?

Yes. The Pfizer-BioNTech COVID-19 vaccine for children ages 6 months to 4 years old and the Moderna COVID-19 vaccine for children ages 6 months through 5 years old have lower amounts of mRNA than the Pfizer-BioNTech and Moderna COVID-19 vaccines for people age 12 and older.

Are there any children who shouldn’t get a COVID-19 vaccine?

COVID-19 vaccines shouldn’t be given to a child with a known history of a severe allergic reaction to any of the vaccine’s ingredients. If this is the case, your child might be able to get different COVID-19 vaccine in the future.

Can a COVID-19 vaccine give a child COVID-19?

No. The COVID-19 vaccines currently available and being developed in the U.S. don’t use the live virus that causes COVID-19.

Can a COVID-19 vaccine affect fertility or menstruation?

There is no evidence that any vaccines, including COVID-19 vaccines, cause fertility problems in men or women.

COVID-19 vaccines might affect menstrual cycles. A survey of more than 39,000 people between ages 18 and 80 showed that 42% of people with regular menstrual cycles had heavier bleeding than usual after vaccination.

In contrast, 44% reported no change and 14% had lighter periods than usual. In addition, 71% of people using long-acting reversible contraceptives, 39% of people using gender-affirming hormones and 66% of post-menopausal people reported breakthrough bleeding. All of the people surveyed were fully vaccinated against COVID-19 and, to their knowledge, hadn’t gotten COVID-19 before being vaccinated.

Keep in mind that many things can affect menstrual cycles, including infections, stress, sleep problems, and changes in diet or exercise.

Can children who get COVID-19 experience long-term effects?

Anyone who has had COVID-19 can develop a post-COVID-19 condition. Children and teens are less likely to have a post-COVID-19 condition. But long-term health issues can affect younger people. People with post-COVID-19 conditions report a wide range of symptoms.

When people younger than 18 who had COVID-19 were compared with those who didn’t, researchers found higher rates of some health issues. Compared with those who never had COVID-19, young people who did have the disease were more likely to report:

  • Blood clot in the lung.
  • Blood clot in a vein.
  • Heart infection called myocarditis.
  • Thickening of the heart wall called cardiomyopathy.
  • Kidney failure.
  • Type 1 diabetes.

How can children get a COVID-19 vaccine?

Talk to your local health department, pharmacy or your child’s health professional for information on where your child can get a COVID-19 vaccine.

How soon can a child get a COVID-19 vaccine before or after getting another vaccine?

A COVID-19 vaccine and other vaccines can be given at the same visit. COVID-19 vaccinations are now part of the immunization schedule for children age 6 months and older. Kids can get a COVID-19 vaccine during their well-child visit or anytime they become eligible based on the vaccination schedule.

If you have questions or concerns about your child getting a COVID-19 vaccine, talk to your child’s health care team. The health professional can help you weigh the risks and benefits of vaccination.

 

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