FDA clears Moderna and J&J boosters - including “mix and match”

CDC advisors to confirm clinical guidelines Thursday

As expected, the FDA Thursday expanded the Emergency Use Authorizations for the Moderna and Johnson & Johnson Covid-19 vaccines to allow booster doses for many people.

The Moderna boosters are authorized for those 65 and older or at high risk because of where they work or live.

Johnson & Johnson boosters are authorized for any of the approximately 15 million Americans who received the one-shot vaccine. Although the single dose has proven to be about 70% effective, well above the usual standard for vaccines, a booster dose ramps the immune response up substantially — and into the 90-100% efficacy that the Pfizer and Moderna mRNA vaccines have demonstrated.

The FDA also authorized any of the three vaccines as a booster dose, the so-called “mix and match” strategy that has shown interesting results in small trials.

The CDC’s panel of vaccination experts meets Thursday to discuss booster doses of the Moderna and J&J Covid-19 vaccines. The panel will confirm guidelines for clinicians, which then go to the CDC director for final approval. Unless there are any surprises, these additional doses could become widely available as soon as Friday.

Later in the day, the experts will consider the latest data on adverse events associated with the Covid vaccines reported to the CDC.

Adverse events are monitored via multiple channels. The largest system, known as VAERS, collects “raw” information — unverified reports of anything that might be related to a vaccination. Think of VAERS as a mound of dirt that has a couple of diamonds in it. You must go through it all in order to know whether what you have is real. And that’s exactly what CDC experts do with the VAERS data. Although most of it is irrelevant, some warrants further investigation.

The CDC also tracks tens of thousands of people in formal studies, or “active surveillance.” That data is more reliable and complete. Experts review adverse event reports from these and other systems in their effort to swiftly recognize “signals” of potential risks.