You might have heard a radio advertisement warning that if you’ve had Covid, you could get it again and experience even worse symptoms. The message, sponsored by the Health and Human Services Department, claims that updated bivalent vaccines will improve your protection.
This is deceptive advertising. But the public-health establishment’s praise for the bivalent shots shouldn’t come as a surprise. Federal agencies took the unprecedented step of ordering vaccine makers to produce them and recommending them without data supporting their safety or efficacy.
The idea of updating mRNA Covid shots every season originally held promise. One advantage of mRNA technology is that manufacturers can tweak the genetic sequence and rapidly produce new vaccines targeting new variants. Hence the bivalent boosters targeting the BA.4 and BA.5 Omicron variants along with the original Wuhan strain.
But three scientific problems have arisen. First, the virus is evolving much faster than the vaccines can be updated. Second, vaccines have hard-wired our immune systems to respond to the original Wuhan strain, so we churn out fewer antibodies that neutralize variants targeted by updated vaccines. Third, antibodies rapidly wane after a few months.