Why bother with testing? Just take Pfizer at its word that the new Omicron boosters will work.
Until now, COVID-19 vaccines have targeted the original coronavirus strain, even as wildly different mutants emerged. The new U.S. boosters are combination, or "bivalent," shots. They contain half that original vaccine recipe and half protection against the newest omicron versions, BA.4 and BA.5, that are considered the most contagious yet.
These new shots have not been tested at all on humans, but the FDA is approving them anyway.
What could possibly go wrong?