Kids and the Covid-19 vaccine: Is it safe and when can they get it?

When will children get the Pfizer Covid-19 vaccine?

Vaccinations of adolescents have started. States are opening up appointments after the Centers for Disease Control and Prevention recommended Wednesday expanding use of the Pfizer-BioNTech vaccine to 12- to 15-year-olds. A key factor is whether a state has enough vaccine doses available to expand access. Supplies have increased considerably since Covid-19 vaccines began rolling out. However, vaccinating children younger than 12 years is months away. Pfizer, which is testing its shot in the younger children, said it expects to have data and request authorization in September.

Do we need to vaccinate children?

Yes, according to most infectious-disease experts. Children can and do get sick from Covid-19, though research shows they typically experience milder cases and are much less likely than adults and the elderly to be hospitalized or die from the virus. As of late March, more than 3.4 million children had been infected with Covid-19, according to the American Academy of Pediatrics, including nearly 14,000 hospitalizations and 279 deaths. The emergence of more-contagious variants, including the B.1.1.7 variant that was first identified in the U.K. and is now dominant in the U.S., appears to be sending younger patients to the hospital with a higher frequency, making vaccines in young adults and adolescents all the more urgent, some doctors and scientists say. In addition, scientists say children need to be vaccinated to achieve the communitywide, or herd, immunity that renders spread of the virus unlikely. “Vaccines give us the opportunity to really turn the tide on this pandemic, and children and teens really need to be a part of that strategy," said Lisa Costello, a pediatrician and president of the West Virginia chapter of the American Academy of Pediatrics.

Will vaccination be required for school?

This is a tough one, with no simple answer. Local school districts decide whether to require vaccinations, usually based on advice from the CDC and state and local health officials. Most school districts in the country already require students to have received vaccinations for mumps, measles and rubella, as well as polio, diphtheria and chickenpox, though many districts grant exemptions to students with pre-existing health problems or religious beliefs conflicting with the mandate. “If you’re in a district that has a lot of vaccine requirements already, I wouldn’t be surprised to see the Covid-19 vaccine just lumped in with those others," said Noelle Ellerson Ng, associate director of advocacy and governance for AASA, the School Superintendents Association, a national umbrella group that represents school districts. Some districts might require Covid-19 vaccinations just for a year or two, until the pandemic dies down, some other school experts say. More than 100 U.S. colleges and universities have said they would require students to be vaccinated.

What are children’s Covid-19 symptoms?

The symptoms are pretty much the same for children as they are for adults, according to the CDC. The symptoms include fever or chills, cough, loss of sense of taste or smell, and headaches. Doctors have also been probing links between Covid-19 and a rare inflammatory condition that causes stomach pain, skin rashes and a high fever. One reason why doctors and public-health experts say they hope children will get vaccinated is research indicating they can carry and transmit the virus even if they don’t show any symptoms.

Does the vaccine pose any risks to children?

Any vaccine comes with the risk of an adverse reaction, and the Covid-19 shots are no different, doctors and vaccine experts say. So far, however, researchers haven’t found evidence the vaccines pose any additional or different risks to children versus adults. The most common side effects to the vaccine, according to the CDC, are flulike symptoms such as fever, muscle aches and chills. Many recipients also experience arm soreness or bruising after receiving the shot. In extremely rare cases, people who have received a Covid-19 vaccine have experienced severe allergic reactions, including anaphylaxis related to chemicals that help package the main ingredient in the Pfizer-BioNTech and Moderna vaccines, a compound known as mRNA. Studies also indicate there aren’t safety risks for pregnant mothers or their unborn children from the vaccines, and that expectant mothers can pass on immunity-boosting antibodies to their fetuses after getting the shots. “Some parents will be skittish about the [Pfizer] vaccine because it’s a new technology, but that just means there’s a lot more educating to be done on the topic," said Peter Hotez, a pediatrician and virology expert at Baylor University. “The safety profile looks about the same for kids as it does for adults."

Write to Robbie Whelan at robbie.whelan@wsj.com