Vaccine tracker: Updates on booster shots and timelines for children

From left: Pfizer/BioNTech, Moderna, and Johnson & Johnson's COVID-19 vaccines.

The nation’s COVID-19 booster shot campaign is underway, with additional doses available for certain vaccines and groups of people, and more on the way.

On Thursday an advisory panel to the US Food and Drug Administration voted to recommend the Moderna booster for people over 65 and adults at high risk of severe COVID-19 or with increased risk at their workplace, at least six months after their second dose. On Friday, the same panel voted to recommend a Johnson & Johnson booster for all adults at least two months after their primary shot of the J&J vaccine.

The FDA is expected to announce its decision on both booster shots by next week.

The Pfizer-BioNTech vaccine currently has the widest booster clearance in the US; it is already available to the groups proposed for the Moderna booster.

The FDA is also reviewing a request from Pfizer to authorize its vaccine for children ages 5 to 11 years old, who still have no access to a COVID-19 vaccine in the US.

Cambridge, Mass. • mRNA-1273    

The basics

Efficacy: greater than 90 percent

Dose: 2 shots, 4 weeks apart

FDA emergency use approval: Dec. 18, 2020

Moderna said it completed its rolling application for full FDA approval on Aug. 25.

Boosters

An advisory panel to the US Food and Drug Administration voted Thursday to recommend the Moderna booster for people 65 and older, adults at high risk of severe COVID-19, and adults who experience risk at their workplace, such as health care, school, and grocery store workers. Moderna now awaits a decision from the FDA and guidance from the Centers for Disease Control and Prevention.

Moderna asked the FDA to authorize a booster shot that contains half the active ingredient of its already authorized vaccine. The booster would have 50 micrograms of messenger RNA, whereas each dose in the primary series has 100 micrograms.

On Aug. 12 the FDA expanded the emergency use authorization for the Moderna vaccine to allow certain immunocompromised individuals to receive a booster shot.

Adolescents and children

Moderna’s vaccine can only be administered to adults in the US at this time. On June 10, the company announced that it requested FDA emergency use authorization for its vaccine in adolescents, following non-peer-reviewed data that suggested it worked in a 3,700-person study of 12 to 17-year-olds. The company is still awaiting a decision, and a separate study in children between 6 months and 11 years old is ongoing.

Updated Oct. 14

New York City | Germany • BNT162b2    

The basics

Efficacy: 91 percent

Dose: 2 shots, 3 weeks apart

FDA Emergency Use Approval: Dec. 11, 2020

The FDA granted the Pfizer-BioNTech vaccine full approval on Aug. 23 for individuals 16 years of age and older. It has been available through emergency use authorization for adolescents ages 12-15 since May 10.

Boosters

The FDA authorized Pfizer-BioNTech booster shots on Sept. 22 for individuals:

• 65 and older
• 18-64 years old and at high risk of severe COVID-19
• 18-64 years old whose job puts them at high risk of serious complications of COVID-19, including health care, school, and grocery store workers

The clearance, which makes booster doses available to millions of Americans, was narrow compared to Pfizer’s original request, which would have covered any American 16 years of age and older who already received the two-dose vaccine.

On Aug. 12 the FDA expanded the emergency use authorization for the Pfizer-BioNTech vaccine to allow certain immunocompromised individuals to receive a third dose.

Adolescents and children

Pfizer asked the FDA on Oct. 7 to clear a version of its COVID-19 vaccine made for children ages 5 to 11. The FDA expects its advisory committee to issue a recommendation during a meeting on Oct. 26.

Pfizer said kids would receive a two-shot vaccine series, but that it would be a smaller dose than what is used in adolescents and adults.

The FDA expanded Pfizer and BioNTech’s emergency use approval to cover adolescents 12 to 15 years old on May 10.

Pfizer is studying different doses of its vaccine in children 6 months to 11 years old. The study breaks out participants into three cohorts: a 5- to 11-year-old age group; a 2- to 5-year-old age group; and a 6-month to 2-year-old age group. Early data readouts for the lower-age-group trials are expected as soon as the fourth quarter of this year, Pfizer said.

Updated Oct. 12

New Brunswick, N.J. • Ad26.COV2.S    

The basics

Efficacy: 72 percent

Dose: One shot

FDA Emergency Use Approval: Feb. 27, 2020

Boosters

A panel FDA experts voted on Oct. 15 to recommend a Johnson & Johnson booster for all adults at least two months after their primary shot. The FDA is expected to announce its decision on the Johnson & Johnson booster shot by the week of Oct. 18. Although the FDA isn’t required to follow its panel’s recommendation, it typically does.

Adolescents and children

The company said in an e-mail to the Globe that it expects to begin a study in 12- to 17-year-olds in the fall.

Based on the results of that trial, additional studies to test the vaccine in children as young as a few months old would begin. In April, the company expanded its ongoing vaccine trial to include adolescents, beginning with those 16 and older. Johnson & Johnson has not released data from that study.

Updated Oct. 15