Europe has endorsed an updated protein-based COVID-19 booster that targets the globally dominant LP.8.1 variant and extends eligibility to adolescents aged 12 years or older.

The positive opinion came from the Committee for Medicinal Products for Human Use of the European Medicines Agency (EMA), which recommended changes to the marketing authorization of Bimervax (HIPRA Human Health). The expanded indication lowers the minimum booster age from 16 to 12 years in individuals previously vaccinated with an mRNA-based COVID-19 vaccine.

Reformulating the vaccine to cover the SARS-CoV-2 LP.8.1 variant — now the most widely circulating strain worldwide, surpassing JN.1 — is expected to play a central role in Europe’s 2025-2026 vaccination campaign strategy.

The vaccine will be administered as a single booster dose at least 6 months after a previous mRNA COVID-19 vaccine, typically administered as an injection in the upper arm.

Bimervax is a recombinant vaccine that contains laboratory-produced parts of the SARS-CoV-2 spike protein. The vaccine includes an adjuvant designed to boost the body's immune response. 

When administered, the immune system recognizes the protein-adjuvant combination as foreign and produces natural defenses, including antibodies and T cells. If a vaccinated person later encounters SARS-CoV-2, the immune system recognizes the spike protein on the virus and responds by producing antibodies and activating immune cells that work together to neutralize the virus, prevent cellular entry, and eliminate infected cells.

Clinical Evidence

The vaccine's benefits were assessed through an immunobridging study that compared immune responses between Bimervax and the authorized mRNA vaccine Comirnaty (BioNTech Manufacturing GmbH), which covers the original Wuhan SARS-CoV-2 spike protein. 

The study included 765 adults who had completed primary vaccination with two doses of Comirnaty and subsequently received a booster dose of either Bimervax or Comirnaty. While Bimervax produced lower antibody levels against the original SARS-CoV-2 strain compared with Comirnaty, it generated higher antibody levels against the Beta and Omicron variants and comparable levels against the Delta variant. 

Additional supportive data came from an ongoing study involving 36 adolescents aged 16-17 years, with immune response data available for 11 participants. This study demonstrated that Bimervax produced adequate immune responses in adolescents, with antibody production comparable to that observed in adults who received the vaccine.

The most common side effects, affecting more than 1 in 10 people, include injection site pain, headache, fatigue, and muscle pain. Less frequent adverse effects include lymphadenopathy, gastrointestinal symptoms, fever, axillary pain, and injection site reactions such as redness, hardness, or swelling.

LP.8.1 Variant Targeting

The EMA's Emergency Task Force (ETF) has recommended updating COVID-19 vaccines to target the LP.8.1 variant, which has surpassed the JN.1 variant to become the most widely circulating strain worldwide. This recommendation follows consultation with the World Health Organization, international partners, and vaccine manufacturers, considering viral evolution data and animal studies on LP.8.1-targeting candidate vaccines.

The ETF noted that vaccines targeting JN.1 or KP.2 strains could still be used in 2025 vaccination campaigns until LP.8.1-updated vaccines become available. All marketing authorization holders are expected to update their vaccine compositions according to this recommendation.

National EU authorities will make final decisions about vaccination campaigns for 2025-2026 based on their country-specific situations. 

As with all vaccines, Bimervax should be administered under close medical supervision with appropriate treatment available for potential allergic reactions.

Detailed product recommendations will be published in the updated summary of product characteristics following European Commission approval of the marketing authorization changes.