US FDA advisers unanimously back second shot of J&J COVID-19 vaccine

Outside advisers to the US Food and Drug Administration on Friday voted unanimously to recommend regulators authorize a second shot of Johnson & Johnson's COVID-19 vaccine to better protect Americans who received the one-dose vaccine.

The FDA's Vaccines and Related Biological Products Advisory Committee backed the shots for all J&J recipients aged 18 and older at least two months after their first dose.

The FDA is not bound to follow the advisory panel recommendations, but typically does.

After hearing presentations from J&J and FDA scientists, many members of the advisory panel asked if J&J's single-dose vaccine should actually be considered a two-dose shot for everyone.

They pointed to the lower levels of virus neutralizing antibodies it provokes compared to vaccines using messenger RNA (mRNA) technology from Moderna Inc and Pfizer Inc /BioNTech SE.

"There is a public health imperative. What we're seeing is this is a group with overall lower efficacy than we have seen with the mRNA vaccine, and so there is some urgency to do something," said Dr. Arnold Monto, an epidemiologist at the University of Michigan's School of Public Health who chaired the meeting. Dr. Peter Marks, director of the FDA's Center for Biologics Evaluation and Research, raised concerns that the data presented by J&J did not reflect all of the information on the vaccine's performance.

"There are some real challenges here. All of the data do not fully align with this being a vaccine that retains excellent activity over time, against all forms of disease or even against severe forms of disease," Marks said.

J&J scientists said their vaccine was more durable than the mRNA vaccines.

Dr. Dan Barouch, a Harvard vaccine researcher who helped design J&J's COVID-19 vaccine, presented data from a study published on Friday in the New England Journal of Medicine. It found antibody levels from the J&J vaccine were "substantially lower" than the two mRNA vaccines, but that the immune responses remained durable, "with little evidence of decline for over eight months."

Dr. Eric Rubin, an infectious disease expert at the Harvard Chan School of Public Health, said, "If the vaccine isn't adequate, it should be boosted and everybody should get it."

After the vote, Rubin said he expects that getting the second dose later than two months after the first should be safe. While the data are scarce, he said, "there isn't much to suspect that it's wrong," adding, "I certainly am supportive of those individuals getting another dose."

Marks said the agency would consider the panel's request to call the second shot an additional dose rather than a booster, reflecting many of the panel members' view that it should have been a two-shot vaccine from the beginning.

Once the FDA signs off on the second dose, the US Centers for Disease Control and Prevention will make specific recommendations on who should get the shots. CDC advisers are scheduled to meet to discuss the boosters next week.

On Thursday, the panel unanimously backed booster shots of Moderna's COVID-19 vaccine for Americans aged 65 and older and those at high risk of severe illness or occupational exposure to the virus.

The US health agencies authorized boosters of the Pfizer/BioNTech vaccine last month.

US health officials have been under pressure to authorize the additional shots after the White House announced plans in August for a widespread booster campaign pending approvals from the FDA and the CDC. -- Reuters