Three doses of Pfizer’s COVID-19 vaccine provide strong protection for children under 5 years old, the company announced Monday. This is another step towards shots for the youngest kids starting in the early summer.
Pfizer will submit its findings to the U.S. regulators this week. Moderna, a rival company, is currently being evaluated by the Food and Drug Administration. The agency has set June 15 as a tentative deadline for its independent scientific advisors to discuss publicly the data.
This news comes after months and months of anxious waiting from parents who desperately want to vaccinate their children, including toddlers, preschoolers and babies. The only group not eligible for COVID-19 vaccine in the United States is the 18 million children under 5.
Pfizer's approach has been difficult to figure out. Pfizer aims to give babies an extra low dose, just one-tenth the amount that adults get. However, it discovered that two shots weren't strong enough to be effective for preschoolers during its trial. Researchers gave a third shot during the winter surge to over 1,600 children, ranging in age from 6 months to 4 year old.
Pfizer and BioNTech released a press release stating that the extra shot worked, revving up children's levels virus-fighting antibodies to the point where they could meet FDA requirements for an emergency vaccine.
The companies stated that preliminary data suggests the three-dose series is effective in preventing symptoms of COVID-19. However, they cautioned that the calculation was based only on 10 cases among the study participants as of April. According to study rules, at least 21 cases must be present in order to determine the effectiveness of the treatment. Pfizer promises an update when more data becomes available.
Although the effectiveness of vaccines could be affected, Dr. William Moss of Johns Hopkins Bloomberg School of Public Health said that "all of these are very positive for parents who are looking forward having a vaccine to treat their younger children in coming months." He was not part of this study.
The vaccine could be "an important tool to help parents safeguard their children," said Dr. Jesse Goodman, Georgetown University's former FDA vaccine chief. He cautioned, however, that it is important to monitor how long protection lasts. This is especially true for serious diseases.
What's next? Dr. Peter Marks, FDA's chief vaccine officer, has promised that the agency would "move quickly but not sacrifice our standards" when evaluating small doses of Pfizer or Moderna.
It will be difficult to compare the approaches of the two companies to vaccinating the youngest children.
Moderna requested FDA approval for two shots, each with a quarter of what was given to adults. Moderna's study showed that the effectiveness against symptoms of COVID-19 was only 40% to 50% in adults who had received two doses of vaccines.
