A US government advisory panel met Friday to decide whether to approve administering booster shots of Pfizer-BioNTech’s coronavirus vaccine, with Israeli health officials presenting figures indicating waning immunity against infection among all age groups around six months after vaccination.
The panel, made up of outside experts who advise the Food and Drug Administration, were scheduled to vote on one basic question: Does the evidence show that a Pfizer booster would be safe and effective for people 16 and older? In the event of a yes vote, the FDA is expected to quickly approve boosters for Pfizer’s shot.
Israeli experts presented the FDA with the findings of an Israeli study uploaded last month to online journal medRxiv ahead of peer review, comparing rates of infection and severe COVID during a several week period in July among people vaccinated at different times.
The study said people over 60 who received a second dose of the Pfizer vaccine in March were 1.6 times more protected against infection and 1.7 times more protected against severe morbidity than those who got a second shot in January. It added that similar figures were recorded in other age groups.
“These results indicate a strong effect of waning immunity in all age groups after six months. Quantifying the effect of waning immunity on vaccine effectiveness is critical for policymakers worldwide facing the dilemma of administering booster vaccinations,” the study says.
The figures were also included in a presentation Thursday by researchers from the Health Ministry, Gertner Institute, Hebrew University of Jerusalem, Technion University and Weizmann Institute of Science on vaccine effectiveness over time.
On Wednesday, a study conducted in Israel was published that shows individuals given a third vaccine dose are nearly 20 times more protected against serious illness and more than 10 times more protected against infection, compared with those who received their second dose at least five months previously.
If the FDA panel gives the go-ahead for an extra dose of the Pfizer vaccine, the more thorny question of who should get the shots and when will be debated next week by advisers to the Centers for Disease Control and Prevention. The CDC generally adopts the group’s recommendations, which set policy for US vaccination campaigns.
Some group members have made clear they favor giving third doses to older people, nursing home residents and front-line health care workers, rather than all adults.
Separate FDA and CDC decisions will be needed for people who received the Moderna or J&J shots can get boosters.
Friday’s meeting came as the Delta variant continues to drive US “cases” and deaths back to levels not seen since last winter. That has given urgency to efforts by top health officials to shore up Americans’ protection against the virus.
Dr. Peter Marks, FDA’s top vaccine regulator, acknowledged the intense disagreements in opening remarks to the agency’s advisory panel.
“We know there may be differing opinions in interpreting the data,” he said. “We strongly encourage all the different viewpoints to be voiced and discussed regarding the data which is complex and evolving.”
US President Joe Biden’s top health advisers, including the heads of the FDA and CDC, first announced plans for widespread booster shots a month ago, targeting the week of September 20 as an all-but-certain start date. It said boosters would be dispensed eight months after the second dose of the Pfizer and Moderna vaccines.
But that was before FDA staff scientists had completed their own assessments of the data. Some experts questioned whether Biden was breaking his own pledge to “follow the science” on COVID-19 by getting out ahead of government scientists.
Earlier this week, two top FDA vaccine reviewers joined a group of international scientists in publishing an editorial rejecting the need for boosters in healthy people.
The scientists said continuing studies show the shots are working well despite the Delta variant.
Pfizer was expected Friday to present data suggesting immunity from its vaccine begins to wane somewhere around six to eight months after the second dose.