EMA’s Emergency Task Force (ETF) considers that adapted mRNA bivalent vaccines targeting the original strain and Omicron BA.4-5 subvariants of SARS-CoV-2 may be used for primary (initial) vaccination. These vaccines are currently only authorised as boosters.
In reaching this conclusion, the ETF reviewed laboratory (non-clinical) studies and data on the immune response following natural infection with Omicron BA.4-5 in unvaccinated people who had not been previously infected with SARS-CoV-2.
The data suggest that primary vaccination with these adapted bivalent vaccines should give rise to a broad immune response in people who have not yet been exposed to, or vaccinated against, SARS-CoV-2.
The ETF further noted that the safety profile of the adapted vaccines when used as boosters is comparable to that of the original mRNA vaccines, for which the safety profile is well established…
