The European Medicines Agency’s (EMA) Emergency Task Force (ETF) has concluded that adapted mRNA bivalent COVID-19 vaccines targeting the original strain and the Omicron BA.4/BA.5 subvariants may be used for primary vaccination in children and adults.
In its decision, the ETF reviewed non-clinical studies and data on the immune response following natural infection with Omicron BA.4/BA.5 in unvaccinated people who had not been previously infected with SARS-CoV-2.
The data suggested that primary vaccination with adapted bivalent vaccines, which are currently only authorised as boosters, should induce a broad immune response in those who have not yet been exposed to, or vaccinated against, SARS-CoV-2.
It was also noted that the safety profile of the bivalent vaccines when used as boosters is comparable to that of the original mRNA vaccines, for which the safety profile is well established.
National authorities may now decide to use these adapted bivalent vaccines for primary vaccination in national vaccination campaigns, based on the ETF’s recommendations.
Further clinical research and observational studies are expected to provide additional information on the safety and effectiveness of the bivalent vaccines for primary vaccination, especially in children.
‘Although there are limitations to the available data, it is reasonably expected that the bivalent
original/Omicron BA4-5 mRNA vaccines can elicit priming against SARS-CoV-2 and that they would have a similar safety profile as the originally approved mRNA vaccines in previously unvaccinated persons,’ the ETF said in a statement.
Since the declaration of the COVID-19 pandemic in early 2020, the virus has continuously evolved, resulting in a series of variants of concern. Currently, the viruses circulating worldwide are of the Omicron lineage, with several subvariants recognised, including the emerging BQ.1 and BQ.1.1 subvariants. In response, some vaccine manufacturers have adapted their approved vaccines.
Two adapted bivalent vaccines targeting the Omicron BA.4/BA.5 subvariants and the original strain of SARS-CoV-2 are currently authorised for use in the EU as booster doses.
This includes Pfizer and BioNTech’s jointly developed Omicron BA.4/BA.5 bivalent COVID-19 vaccine, recently approved by the EMA for booster doses in children and adults, as well as Moderna’s Omicron BA.4/BA.5 vaccine, approved as a booster for adults and adolescents.