In September, a new version of the COVID-19 boosters became available to the public without any clinical testing. They are called bivalent vaccines and are being offered by Pfizer-BioNTech and Moderna.
Bivalent means they contain not just one mRNA that codes for a protein from a viral strain, but two types. The first mRNA makes cells manufacture a toxic protein from the ancestral strain of the SARS-COV-2 virus, the original virus from Wuhan. The second mRNA forces cells to make a protein that comes from Omicron and its BA.4/5 subvariants.
The logic here is to give people a well-rounded protection from existing variants as well as any upcoming mutations. Some immunologists believe that future mutations can still be closely related to the original Wuhan strain and that’s why its mRNA is kept in the new booster. But others disagree. Dr. Sean Lin, a former vaccine developer at the Walter Reed Army Institute, says it’s not in favor of the virus to maintain its similarity to the original strain, which questions the whole logic of these boosters being effective….