Avian Flu Diary: ACIP: Framework for Booster Doses of COVID-19 Vaccines

#16,155

Although the big news to come out of yesterday's CDC ACIP (Advisory Committee for Immunization Practices) meeting was their endorsement of the Pfizer-BioNTech’s licensed COVID vaccine for people 16 and older (see CDC statement below), they also spent much of the day going over the latest data on Vaccine Effectiveness (VE) and safety, and the growing call for booster shots.

CDC Media Statement: CDC Statement Following ACIP Pfizer-BioNTech Vote
Media Statement
For Immediate Release: Monday, August 30, 2021
Contact: Media Relations
(404) 639-3286
Today, CDC Director Rochelle P. Walensky, M.D., M.P.H., endorsed the CDC Advisory Committee on Immunization Practices’ (ACIP) recommendation for use of the Pfizer-BioNTech’s licensed vaccine for people 16 and older.
This recommendation follows FDA’s decision to fully approve Pfizer’s COVID-19 vaccine.
The ACIP recommendation comes 9 months after the committee’s interim recommendation and after an exhaustive review of the scientific evidence demonstrating safety and effectiveness, and supporting continued use of the vaccine.
“We now have a fully approved COVID-19 vaccine and ACIP has added its recommendation. If you have been waiting for this approval before getting the vaccine, now is the time to get vaccinated and join the more than 173 million Americans who are already fully vaccinated,” said CDC Director Dr. Rochelle Walensky.

As we've been noting for months, the high-flying VE rates reported very early (both in clinical trials and the opening months of 2021) - suggesting a > 90% protection by mRNA vaccines against SARS-CoV-2 infection - have begun to decline (see MMWR: Two Early Release COVID VE (Vaccine Effectiveness) Studies).

Protection against severe illness, hospitalization, and death remain reassuringly high, however.

For now, it isn't clear whether this drop is simply due to the time elapsed since the the initial shot, the introduction of a much more transmissible Delta variant, or both. Either way, since mid-July the debate has escalated over the need for, and the best timing of, booster shots (see Joint Statement from HHS Public Health and Medical Experts on COVID-19 Booster Shots).

While partially a political decision, it is one that must be guided by both logistical concerns and the best medical evidence available at the time.

ACIP is currently deliberating the scientific evidence for their need, the likelihood of benefit from a booster shot, and the practicalities of promoting a booster when a large portion of the United States - and the world - has yet to receive their first shot.

We've a series of slides (Framework for COVID-19 booster doses pdf [53 pages]) from yesterday's ACIP meeting that outline the questions on the table, the evidence to date, and what more we need to know before embarking down this road.

I highly recommend downloading and reviewing the entire 53-slide set. But a few highlights include:

This presentation presents a series of slides (#11- #27) illustrating the significant decline in vaccine protection against infection, along with a far more modest reduction in protection against hospitalization, particularly in those over the age of 75.

It should be noted that if last year (see A COVID Vaccine Reality Check), had we been promised a vaccine that would be 80% protective against hospitalization in the most vulnerable ( age > 75) population, we'd have considered it a `win'.

There are concerns, however, that the VE against severe illness, hospitalization, and death may continue to erode over time. Hence the growing calls for offering booster shots.

Although plans have been announced to begin offering booster shots as soon as September 20th, it is unlikely that we'll have much robust data by then on the (short-term) effectiveness of booster shots against the Delta Variant (or other VOCs), or how long any enhanced protection might last.

Yesterday's presentation by ACIP offers no decision on booster shots, but suggests they may be leaning towards a more limited roll-out of booster shots to begin with, and they continue to stress the need to get unvaccinated individuals their initial doses.

Slide #46 (below) illustrates a possible recommendation by the Committee, which would target the highest risk individuals (LTCF residents, HCW, Adults > 65/75 years of age) for booster shots initially.

The report concludes with:

You'll find the entire day's list of slide presentations available at the following link:

ACIP Presentation Slides: August 30, 2021 Meeting

Note: These files are not yet 508

Slides will be added as they become available.
August 30, 2021