Child-size doses of Pfizer’s Covid-19 vaccine appear safe and nearly 91% effective at preventing symptomatic infections in five to 11-year-olds, according to newly released study details.
The information was made public as the US considers opening vaccinations to this age group.
The jabs could begin in early November – with the first children in line fully protected by Christmas – if regulators give the go-ahead.
Details of Pfizer’s study were posted online on Friday, with the country’s Food and Drug Administration (FDA) expected to post its independent review of the company’s safety and effectiveness data later in the day.
Advisers to the FDA will publicly debate the evidence next week. If the agency ultimately authorises the jabs, the Centres for Disease Control and Prevention (CDC) will make the final decision about who should receive them.
Full-strength Pfizer shots are already authorised for anyone aged 12 or above, but paediatricians and many parents are awaiting protection for younger children to stem rising infections from the more contagious Delta variant and help keep children in school.
More than 25,000 paediatricians and primary care providers have already signed up to deliver the jabs to this age group.
The Biden administration has purchased enough child-size doses for the nation’s roughly 28 million five to 11-year-olds. If the vaccine is cleared, millions of doses will be shipped around the country, along with child-size needles.
A Pfizer study tracked 2,268 children in this age group who received two doses, three weeks apart of either a placebo or the low-dose vaccine. Each dose was one-third the amount given to teenagers and adults.
Researchers calculated the low-dose vaccine was nearly 91% effective, based on 16 Covid-19 cases in youngsters given dummy shots versus three cases among vaccinated children. There were no severe illnesses reported among any of the youngsters, but the vaccinated ones had much milder symptoms than their unvaccinated counterparts.
In addition, young children given the low-dose shots developed antibody levels that were just as strong as teenagers and young adults who received regular-strength vaccinations.
This was important information considering that hospitalisations of mostly unvaccinated children reached record levels last month.
The CDC reported earlier this week that even as the Delta variant surged between June and September, Pfizer vaccinations were 93% effective at preventing hospitalisations among 12 to 18-year-olds.
Pfizer’s study of younger children found the low-dose jabs proved safe, with similar or fewer temporary side effects such as sore arms, fever or achiness that teenagers experience.
The study was not large enough to detect any extremely rare side effects, such as the heart inflammation that occasionally occurs after the second dose, mostly in young men.
While children run a lower risk of severe illness or death than older people, Covid-19 has killed more than 630 Americans aged 18 and under, according to the CDC.
Nearly 6.2 million children have been infected with coronavirus, more than 1.1 million in the last six weeks as the Delta variant surged, the American Academy of Paediatrics said.
Moderna was also studying its Covid-19 vaccine in primary school-age children. Pfizer and Moderna were studying even younger children as well, down to six-month-olds. Results are expected later in the year.