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It’s been a busy week in the world of official action on COVID-19 boosters, culminating today with federal officials highlighting the details and importance of recent announcements from federal regulators during a White House media briefing.
White House COVID-19 Response Team members Rochelle Walensky, MD, MPH, Anthony Fauci, MD, and Jeffrey Zients updated pandemic numbers, shared some promising booster data out of Israel, and answered questions about expanding booster eligibility and administering boosters during pregnancy.
They also said whether people yet to receive a booster shot are still considered “fully vaccinated.”
“This week marks another important step in our vaccination program,” said Centers for Disease Control and Prevention (CDC) Director Walensky. She endorsed the CDC’s Advisory Committee on Immunization Practices’ unanimous support of Moderna and Johnson and Johnson boosters for select groups yesterday.
The additional booster authorizations come as overall COVID-19 case numbers, hospitalizations, and deaths continue to fall in the United States.
As of October 21, the 7-day daily average number of cases fell to about 73,000 — a 15% drop compared with the previous week. At the same time, 7-day average daily hospital admissions decreased to 6000 — a drop of 10%, and deaths were down about 4% to 1250 per day, Walensky said.
While she is “very encouraged” by the falling numbers, Walensky added that work remains — 93% of US counties still have substantial or high levels of community transmission.
Scientific and Clinical Evidence
A National Institutes of Health-backed mix-and-match booster study — released as a preprint on October 15 — provided “the fundamental scientific basis for the deliberations of the [US Food and Drug Administration] and ultimately the CDC on boosters,” said Fauci, chief medical advisor to the president.
“The bottom line is that boosters worked very well for increasing the titer of neutralizing antibodies in this study,” Fauci said. People who received the same brand of COVID-19 vaccine for their primary vaccination and booster showed a 4- to 24-fold jump in their antibody titers. For people who switched vaccine products when they received a booster, the increase was 6.2 to 76-fold greater.
The clinical picture can be seen in data out of Israel that shows a “striking” decrease in number of confirmed infections among people who received a booster shot, Fauci said.
The numbers show that a third shot was associated with “almost a 19-fold lower incidence of severe disease in people older than 60 years old and more than a 22-fold lower incidence of severe disease in younger people from 40 to 60 year old,” he said.
Fauci also highlighted booster efficacy data announced Thursday by Pfizer/BioNTech from their randomized controlled trial of more than 10,000 people who received two doses of their COVID-19 vaccine and then a 30-microgram booster.
“They had a relative vaccine efficacy of close to 96% compared to individuals who were not boosted,” he said.
The data revealed five COVID-19 cases in the booster group versus 109 infections in the nonbooster group, Fauci said, and a “very favorable safety profile.”
Ready for Rollout
“We are ready to execute on boosters.” Zients, COVID-19 Response Team counselor to the president, said during the briefing.
“We are ready to get booster shots in the arms of tens of millions of newly eligible Americans,” he said, given an ample supply of all three vaccines now available.
“The bottom line is that our booster program is off to a very strong start,” Zients said.
Pregnancy and Other Considerations
In response to a reporter’s question about whether boosters are recommended for pregnant or breastfeeding women, Walensky first addressed a bigger-picture concern.
“First and foremost, I want to really emphasize how important it is to get a primary series if you’re pregnant. We have relatively low rates of vaccination for pregnant women in general,” she said.
In terms of getting a booster immunization, Walensky said, “Yes. If you are eligible for a boost and you’re pregnant, you should also get your boost during that period of time.” She said the same recommendation applies to women who are nursing as well.
Another journalist asked about the likely timeline for expanding boosters to those currently ineligible.
“We are following the data in real time and we are looking at its ongoing efficacy as well as its potential for waning in our other age groups,” Walensky said. “And we will update our recommendations as soon as we have more data.”
Now that boosters are rolling out in earnest, the experts were asked if immunization with one shot of Johnson and Johnson or two doses of the Moderna or Pfizer vaccine still count as “fully vaccinated.”
“It’s a really great question,” Walensky said. “Right now we don’t have booster eligibility for all people. So we have not yet changed the definition of fully vaccinated and we will continue to look at this.
“We may need to update our definition of fully vaccinated in the future,” she added.
Based on a White House COVID-19 Response Team media briefing October 22, 2021.
Damian McNamara is a staff journalist based in Miami. He covers a wide range of medical specialties, including infectious diseases, gastroenterology, and critical care. Follow Damian on Twitter: @MedReporter.