(J. Harris: Note that East Texas Covid has “burned out” for now.)
(J. Harris: Good HOPKINS summary of recent Covid Vaccine decisions)
BOOSTER DOSES The US FDA’s Vaccines and Related Biological Products Advisory Committee during 2 days of meetings last week considered several questions related to booster doses for SARS-CoV-2 vaccines. The panel’s recommendations are not binding, although the FDA generally follows the advice of its committees. ModernaThe vaccine advisory panel on October 14 voted unanimously to endorse a booster dose of Moderna’s SARS-CoV-2 vaccine, administered at least 6 months after the second dose. The vote supports authorizing an additional dose of the vaccine in the same groups authorized for a booster dose of the Pfizer-BioNTech SARS-CoV-2 vaccine, including individuals aged 65 and older, those ages 18 to 64 at a higher risk for severe disease, and people at risk of exposure due to their occupation. The advisory panel also discussed when booster doses should be provided to all adults but concluded it is too soon to make that decision. The Moderna booster under consideration is 50μg, half the dose of the initial 2 shots, while the authorized booster for the Pfizer-BioNTech vaccine is the same formulation as the FDA-approved 2-dose vaccine. Moderna claims a half dose is enough to activate the immune system while still stretching the world’s supply of available vaccines. Data from Moderna show that the booster dose did not produce the 4-fold antibody increase set as a guideline by the FDA for authorizing boosters, but Moderna said it was because of existing high levels of antibodies in study participants. Some panel members expressed concern over some of the data provided by Moderna—including on how best to measure correlates of protection and durability provided by a half dose—but not enough to prevent endorsement of booster doses. Others noted that avoiding public confusion over which vaccines were approved for booster doses and why played a role in their decision. J&J-JanssenDuring a second day of meetings on October 15, the vaccine advisory panel voted unanimously to endorse a second dose of the J&J-Janssen SARS-CoV-2 vaccine for all recipients. This meeting saw more controversy than previous meetings on booster shots for the Pfizer-BioNTech and Moderna SARS-CoV-2 vaccines, with some panelists reportedly unhappy with multiple slides presented by J&J-Janssen that contained data not previously vetted by the FDA. Additionally, the companies presented data on boosters given at 6 months from a study with a sample size of only 17 volunteers. Panelists expressed frustration with and hesitancy to make a decision based on the limited data, but all the panelists agreed that anyone who received the J&J-Janssen vaccine should be eligible for a second dose, with some saying the vaccine should be considered as a 2-dose regimen. The concerns revolved around data showing that a single dose of J&J-Janssen offered lower protection than 2 doses of either the Pfizer-BioNTech or Moderna vaccines. Mix & MatchFollowing its vote on the J&J-Janssen vaccine, the panel discussed the so-called “mix & match” strategy, which could allow heterologous booster doses for certain populations. Data from an NIH study released last week showed that the antibody levels of those who initially received the J&J-Janssen shot rose 76-fold in 15 days following a booster with Moderna and 35-fold after a booster with Pfizer-BioNTech. By comparison, a second dose of J&J-Janssen only raised antibody levels 4-fold in the same timeframe. It is worth noting that there were concerns because the NIH study results were based on a small number of volunteers and only reported short-term findings. Despite these concerns, some panelists claimed the data are enough to convince them to support a mix & match strategy, something that is fairly common in other countries. The FDA is expected to authorize boosters for some Moderna and all J&J-Janssen vaccine recipients as early as this week and also could make a decision on the mix & match strategy. The US CDC’s Advisory Committee on Immunization Practices (ACIP) is scheduled to meet this week to make its own recommendations on booster doses, meaning millions more people in the US could be eligible for additional shots by the end of the week. AND LAST BUT NOT LEASED:
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