Health experts advising US regulators will vote Wednesday on whether Covid-19 vaccines from Pfizer Inc., BioNTech SE, and Moderna Inc. should be approved for use in children as young as six months.

A positive recommendation would almost certainly result in the expansion of the Covid-19 vaccination campaign in the United States to the 19.6 million children aged 6 months to under 5 years old, the last group of people in the country waiting for shots.

Moderna’s two-dose vaccine is being considered for FDA approval in children aged 6 months to 5 years, while Pfizer’s three-dose shot is being considered for children aged 6 months to 4 years.

The FDA reviewed data from the companies’ clinical trials and determined that the vaccines were generally safe and effective. The Advisory Committee on Vaccines and Related Biological Products is made up of physicians, infectious-disease scientists, and other health professionals. The panel meets on a regular basis to discuss vaccines and medicines under FDA review.

Following a day-long meeting, the committee will vote on whether the FDA should approve the Pfizer-BioNTech and Moderna vaccines for young children.

Before the vaccines can be used outside of clinical trials, the FDA, which regulates medical products, must approve them. Following the FDA’s action, the Centers for Disease Control and Prevention, which provides guidance to doctors, pharmacies, and vaccination sites, would establish the policy for the children to receive the shots.

Many states and vaccination sites wait for the CDC’s approval before beginning to administer shots. According to the, vaccinations could begin as early as June 21. Although hospitalizations increased during the Omicron wave last winter, children are generally at lower risk of developing severe Covid-19. Health officials have encouraged vaccinations for children who are eligible in order to protect not only children but also adults.

The FDA’s vaccines division chief, Peter Marks, opened the meeting by saying that the Omicron surge this winter resulted in more hospitalized children than even a bad flu season, and that it was critical that people “don’t become numb” to pediatric Covid-19 deaths, even if they occur less frequently than in older people.

While some parents of children under the age of five are eagerly awaiting vaccinations for their children, surveys show that the majority of parents are less enthusiastic.

According to a Kaiser Family Foundation poll conducted in April, about 18 percent of parents surveyed wanted to get their child vaccinated right away, while 38 percent plan to wait and see.

According to the survey, approximately 27% of parents do not intend to vaccinate their child at all, and 11% will do so only if required.

Pfizer’s application is based on a 4,526-child study that tested three doses of either a vaccine or a placebo, with all third doses administered between February and April, when the Omicron variant was prevalent in the United States.

The vaccine was found to be about 80% effective in preventing symptomatic Covid-19 in children, according to the study. However, the FDA stated in its staff review that the small number of children who became ill during the trial made it too early to draw “definitive conclusions” on the vaccine’s efficacy.

Irritability and drowsiness were among the side effects experienced by the youngest children. According to the FDA, side effects in children aged 2 to 4 years old included pain at the injection site and fatigue.

The FDA’s review of Moderna’s vaccine was based on studies involving over 6,300 young children who received two doses of either the vaccine or a placebo.

In a study conducted when the Omicron variant was predominant, Moderna’s two-dose vaccine was 37% effective for 2- to 5-year-olds and 51% effective for children 6 to 23 months. With the exception of fever, which was reported more frequently in the younger age groups, children 6 months to 11 years old had lower rates of side effects than adolescents and young adults, according to the FDA.

While the Pfizer-BioNTech and Moderna vaccine studies found no cases of heart-inflammation conditions such as myocarditis, the FDA panel is expected to discuss the issue.

The FDA has identified an increased risk of the conditions in certain people, particularly young men aged 12 to 17.

The first two Pfizer doses are administered three weeks apart, with a third dose administered at least eight weeks later. The two Moderna doses are separated by four weeks.