When Will Kids under Five Get COVID Vaccines? and Other Questions

The shots for the youngest children in the U.S. are not available due to the Omicron wave.

The gap in vaccine access is being bridged by vaccine makers. Moderna requested an emergency use authorization from the FDA to make its vaccine available to children between the ages of six months and six years. Pfizer and BioNTech plan to follow suit by early June with a similar request geared toward children between the ages of six months and five years; the companies recently announced in a press release that their vaccine produced a good immune response in this age group. The Pfizer-BioNTech vaccine is available to children ages five to 11 and adolescents between the ages of 12 and 17. The FDA approved a booster shot for kids ages five to 11 last week. Moderna's vaccine is not available in the U.S. for children aged six years and older.

Moderna's vaccine for U.S. children may be delayed because the FDA plans to wait to review submissions from both companies at the same time.

Scientific American reached out to experts in academia, government and industry to find out why it takes so long to authorize a vaccine for young children.

When will the COVID vaccines for children under the age of five become available?

Assuming the evidence is acceptable to the FDA, sometime in June. Pfizer and Moderna have been submitting data to the agency for months. The FDA will give the data sets to the Vaccines and Related Biological Products Advisory Committee for a public evaluation after reviewing them. Independent experts in various fields will make recommendations for the FDA to consider when making decisions. The vaccine EUAs will be updated during the meetings on June 8, 21 and 22.

Arnold Monto, the acting chair and an epidemiologist at the University of Michigan School of Public Health, said that EUAs could come within one or more days. The risk-benefit equation can be changed by the fact that kids have a lower likelihood of severe COVID outcomes than adults. The vaccine risk for kids who are otherwise healthy may be less.

Why has it taken so long for the vaccine to be approved for young people?

There are many reasons for the delay. Clinical trials with older age groups took priority as initial efforts to develop a vaccine got underway since the risk of death and severe illness was greatest in adults. Testing new immunizations in adults before children is a standard convention in vaccine development.

Pfizer, BioNTech and Moderna have spent months trying to balance COVID protection against potential side effects by testing their vaccines in different dosages and varying the number of doses. Moderna decided on a two-shot regimen of 25 micrograms per dose for young kids, whereas Pfizer and BioNTech decided on a three-shot regimen. The studies have taken a long time. The Pfizer-BioNTech submission was to be evaluated by the FDA in February, but only two-shot data were available. Scientific American asked the FDA about the meeting but did not hear back.

There have been concerns about the safety of the vaccines in young children.

Messenger RNA (mRNA) vaccines are prone to inducing a number of inflammatory responses. Babies and young children are at risk of having convulsions because of the effects of tingly. The evidence so far shows that children achieve strong immunity against the virus that causes COVID, with surprisingly low vaccine doses, and this is important for reducing side effects.

There is a small but increased risk of myocarditis in adolescent boys who are 12 to 17 years old. There is no evidence of myocarditis among the eight million children who have received the vaccine. The data so far is encouraging.

What are the benefits of immunizations?

More than 1,000 children have died from Covid in the US. The effects of COVID on taste and smell in adults may be related to how the central nervous system works.

Is the FDA waiting for Pfizer's data to be in before evaluating Moderna's data?

FDA media staff directed Scientific American to a discussion between FDA commissioner Robert Califf and Andy Slavitt, who was the White House's senior adviser to the COVID response. Califf denied that the FDA was waiting to review Moderna and Pfizer-BioNTech submissions at the same time. Pfizer and BioNTech anticipate their submission will be accepted by the FDA by the time the meetings convene in June.

What data will the FDA consider when making a decision?

How well the vaccines protect against infections is a primary consideration. The Pfizer-BioNTech vaccine had 95 percent protection against severe disease, while the Moderna shot had 94.1 percent efficacy. Moderna has reported that the vaccine's efficacy rate is less than 50 percent in children younger than six. Pfizer and BioNTech announced on Monday that their vaccine was 80 percent effective in preventing disease in children under the age of five. Both vaccines target an ancestral strain of the virus that has been replaced by newer versions. Omicron and its subvariants are better at evading vaccine immunity, which explains why the current efficacy numbers are lower in the kids trial.

The FDA's strict standards remain to be seen, and whether Moderna's lower efficacy figures will satisfy them remains to be seen. Califf told Slavitt that the vaccine can be authorized based on the company's reported efficacy rates. Secondary consideration will be given to the effectiveness of the vaccines against infections. Ofer Levy, director of the Precision Vaccines Program at Boston Children's Hospital, stresses that the degree to which the antibodies correlate with disease protection remains unknown.

Why are some parents hesitant to have their kids vaccinations?

A third of parents in the U.S. are willing to give their children the vaccine right away, while a third are on the fence. Levy says that the parents may be suspicious of the technology or the drug companies.

75 percent of children and adolescents in the U.S. have been exposed to the disease, according to recent data from the CDC. Monto says that the figures should not deter parents from immunizing their children.