ETF concludes that bivalent original/Omicron BA.4-5 mRNA vaccines may be used for primary vaccination


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 EFT 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.

The ETF therefore considered that the bivalent original/Omicron BA.4-5 vaccines may be used in previously unvaccinated children and adults.

Based on these considerations, national authorities may decide to use these adapted bivalent vaccines for primary vaccination in their national vaccination campaigns, should it become necessary. Further clinical research and observational studies are expected to provide additional information on the safety and effectiveness of the bivalent vaccines for primary vaccination.

The ETF’s statement has been issued in the context of its public health emergency response activities. It does not reflect a change to the product information of the authorised vaccines.

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