MedPageToday The FDA and CDC recently announced that previously unvaccinated Americans can now receive only a single dose of the bivalent Moderna or Pfizer mRNA vaccines. To be clear, this is not saying they can choose to have one or two doses and be considered fully vaccinated either way — only one dose is available to them. The CDC made a related decision in respect to international travelers who fly into the U.S. They “will now be considered fully vaccinated 2 weeks after getting a single dose of either the Pfizer or Moderna mRNA vaccine any time after August 16, 2022, when bivalent formulations first became available.” However, a more recent decision from the White House made this announcement moot by eliminating any vaccination requirements for arriving travelers.
In practice, these policy changes will probably not affect many people. The approximately 30% of Americans who have refused all COVID-19 vaccines for over 2 years — often for political reasons and because of widespread misinformation — are unlikely to change their attitudes merely because they are now limited to receiving only a single bivalent vaccine dose. And there would have been few international travelers, particularly foreigners, whose only vaccine experience would have been a single bivalent mRNA vaccine. Even so, it’s worth exploring what lies behind what just happened.
Since the mRNA vaccines were first rolled out in late 2020, the standard primary series always has been two doses, which remains the legal definition of “fully vaccinated.” Indeed, CDC recommends that Americans receive multiple mRNA vaccine doses, either three or four depending on age and health status . Why, then, do FDA and CDC suddenly consider one dose of the bivalent vaccines to be sufficient for unvaccinated people? What data underlie the decisions, and how were those decisions made? The simplest answers are: None and who really knows?
Continue reading