Quick Take:

Public health officials have said that the vaccine is safe for children and that getting them inoculated would help speed up herd immunity. California’s mandate for those 12 and over could take effect as early as January.

California is again on the leading edge of vaccine mandates, requiring all eligible public and private schoolchildren to be vaccinated against COVID-19.

The mandate could take effect for students 12 and older as early as January if there is full federal approval for a COVID-19 vaccine for that age range. Once it’s in effect, students will not be allowed to attend classes in person without being vaccinated, just as with any other required childhood vaccine. Medical and religious exemptions would be available.

Public health officials have said that the vaccine is perfectly safe for children and that getting them inoculated would help bring regions closer to herd immunity.

Here is a breakdown of what we know:

How long has the COVID-19 vaccine been available for children?

The Pfizer-BioNTech COVID-19 vaccine was authorized for emergency use in December for everyone 16 and older and began to be widely available in the spring.

Full approval from the U.S. Food and Drug Administration was granted for people 16 and older in late August.

The Pfizer shot was authorized for emergency use among adolescents 12 to 15 years old in May. Full approval is widely anticipated by November for this age group.

Vaccines for children ages 5 to 11 are not that far off. Pfizer is expected to apply for authorization imminently, citing evidence from trials indicating that the shots are safe and effective for children in that range. The shots could be available for this age group around Thanksgiving, according to the Associated Press.

What’s the safety record of the Pfizer vaccine?

Experts call the Pfizer vaccine safe and effective for children.

Among all age groups, there have been 226 million administrations of the Pfizer-BioNTech vaccination in the U.S. since December, an astonishing mass rollout of vaccinations in a short time that has no parallel in U.S. history.

In that period, 54% of adolescents 12 to 15 have received at least one dose of vaccine, as have 62% of 16- and 17-year-olds. If there were a safety problem with the vaccine for adolescents, it likely would have surfaced by now, experts say.

What about reports of heart inflammation as a Pfizer side effect?

There were some early concerns about myocarditis — inflammation of the heart muscle — being a side effect following administration of the Pfizer-BioNTech vaccine, mostly among young males after getting a second dose.

But further study revealed that of 8.9 million adolescents in the U.S. aged 12 to 17 who had received the Pfizer-BioNTech vaccine through mid-July, cases of myocarditis were rare. There were fewer than 400 reports of myocarditis, the symptoms were generally mild and there were no related reports of death.

Even if myocarditis did occur following vaccination, usually aspirin or another common anti-inflammatory drug would resolve the symptoms, said Dr. Monica Gandhi, a UC San Francisco infectious diseases expert. After reviewing the data, she had her 13-year-old son get his second dose, and he was fine, she said.

The most common adverse pediatric events reported to officials were dizziness, headache and fainting, some of which is likely related to a history of anxiety around needles, according to a report published by the Centers for Disease Control and Prevention. Fainting is common among adolescents after any vaccination, the CDC said.

Why is there a push to vaccinate children when hospitalization rates are so low in this group?

Children, indeed, have low rates of hospitalization and death from COVID-19.

Still, “the risk is not zero,” UCLA medical epidemiologist and infectious diseases expert Dr. Robert Kim-Farley said. More than 600 children under 18 in the U.S. have died after contracting COVID-19. Nearly 300 of them were between 12 and 17.

“This vaccine is safe and effective and will prevent needless suffering, disability and death in children. Any death in a child is to be regretted,” Kim-Farley said.

Children exposed to the coronavirus are also at risk of developing a rare but serious condition known as Multisystem Inflammatory Syndrome in Children, or MIS-C. The condition can cause the heart, lungs, kidneys, brain, skin, eyes or gastrointestinal organs to become inflamed, and is potentially deadly.

Nationally, there have been more than 4,600 cases of MIS-C, and 41 related deaths.

What is the risk to others when teens aren’t vaccinated?

Failing to vaccinate adolescents will only prolong the pandemic, putting other people at risk, epidemiologists say. In Los Angeles County, for example, unvaccinated children 12 to 17 have the highest coronavirus case rate in the past month — 19% worse than among unvaccinated adults under 50 and 33% worse than among unvaccinated older adults.

It’s the older adults, however, who pay the price when coronavirus circulates at high levels in a community. Fully vaccinated grandparents, for example, are at higher risk for coming into contact with the virus, which in turn poses a greater risk of severe illness should they get a breakthrough infection from an unvaccinated grandchild.

“The Delta variant, unlike the Alpha variant, really is just so much more transmissible that children absolutely get it … and they transmit it,” Gandhi said. “If you have all this virus around you, you’re still going to get breakthroughs. And who is going to be susceptible to severe breakthrough? Older people.”

Does the government have the authority to require vaccination for schoolchildren?

Yes, state governments have long required that vaccinations be a condition of entry to classrooms.

Shots in California that are needed for K-12 education include polio, measles, mumps, rubella, varicella, hepatitis B, diphtheria, tetanus and pertussis.

What have the courts said about government mandates for vaccinations?

The courts have previously upheld laws requiring compulsory vaccination: In 1905, the U.S. Supreme Court upheld state laws that require vaccination against communicable diseases. The case stemmed from a Massachusetts law that permitted city health boards to enforce mandatory, free vaccination requirements for adults over 21.

In a 7-2 decision, Justice John Marshall Harlan wrote that “the rights of the individual … may at times, under the pressure of great dangers, be subjected to such restraint, to be enforced by reasonable regulations, as the safety of the general public may demand.”

Are schoolchildren eligible for exemptions from routine childhood vaccinations?

California allows only medical exemptions to vaccines. In 2016, California ended the practice of allowing parents of schoolchildren to seek an exemption from vaccinations due to the family’s personal beliefs.

Schools do not need to be immunized if they attend a home-based private school or learn through an independent study program and do not receive instruction based in a classroom.

Why did California end the practice of ‘personal belief exemptions’?

A Disneyland measles outbreak in late 2014 and early 2015 spread to seven other states, as well as Canada and Mexico, which revealed the risks of declining childhood vaccination rates in California.

Vaccination rates had been declining as a result of a proliferation of myths that vaccines were unsafe, the result of misinformation that officials said endangered public health.

How did people respond to strengthened vaccine requirements in schools?

Two-thirds of California adults responding to a Public Policy Institute of California survey said unvaccinated children should not attend public school. Parents opposed to the law took part in large impassioned protests.

Times staff writer Maura Dolan contributed to this report.

This story originally appeared in Los Angeles Times.