Ministry of Health releases more information on tailored COVID-19 vaccine recalls

The EMA’s Committee for Medicinal Products for Human Use (CHMP) has recommended licensing two suitable vaccines to provide broader protection against COVID-19. Comirnaty Original/Omicron BA.1 and Spikevax Bivalent Original/Omicron BA.1 are intended for people aged 12 years and over who have received at least one primary vaccination against COVID-19. These vaccines are adapted versions of the original Comirnaty (Pfizer/BioNTech) and Spikevax (Moderna) vaccines to target the Omicron BA.1 subvariant in addition to the original SARS-CoV-2 strain.

Vaccines are adapted (i.e. updated) to better match circulating variants of SARS-CoV-2. Adapted vaccines can broaden protection against different variants and should therefore help maintain optimal protection against COVID-19 as the virus evolves.

Studies have shown that Comirnaty Original/Omicron BA.1 and Spikevax Bivalent Original/Omicron BA.1 can elicit strong immune responses against Omicron BA.1 and the original SARS-CoV-2 strain in previously vaccinated individuals. In particular, they were more effective in eliciting immune responses against the BA.1 subvariant than the original vaccines.

The side effects observed with the adapted vaccines were comparable to those observed with the original vaccines and were generally mild and of short duration.

The two CHMP opinions will now be forwarded to the European Commission, which will adopt a final decision.

As the pandemic evolves, the EU strategy is to have a wide range of suitable vaccines that target different variants of SARS-CoV-2 so that Member States have a plurality of options to respond to their needs when designing their vaccination strategies. This is a key part of the overall pandemic strategy because it is not possible to predict how the virus will evolve in the future and which variants will circulate this winter. Other suitable vaccines incorporating different variants, such as the Omicron BA.4 and BA.5 subvariants, are currently under review by the EMA or will be submitted soon and, if approved, will further expand the arsenal of available vaccines. The clinical data generated with the original/BA.1 bivalent vaccines recommended today will support the evaluation and authorization of other suitable vaccines.

The original vaccines, Comirnaty and Spikevax, are still effective in preventing serious illness, hospitalizations and deaths associated with COVID-19 and will continue to be used in vaccination campaigns in the EU, particularly for vaccinations primaries.

National authorities in EU Member States will determine who should receive which vaccines and when, taking into account factors such as infection and hospitalization rates, risk to vulnerable populations, vaccination coverage and availability of vaccines.

Evidence supporting the use of Comirnaty Original/Omicron BA.1

Comirnaty Original/Omicron BA.1 can be used in people aged 12 years and over, at least 3 months after the last dose of a COVID-19 vaccine.

The CHMP opinion on Comirnaty Original/Omicron BA.1 is based on 2 studies. A study in adults over the age of 55 who had previously received 3 doses of Comirnaty (primary and booster) found that the immune response to the Omicron BA.1 subvariant was higher after a second booster dose of Comirnaty Original/ Omicron BA.1 only after a second dose of the original Comirnaty vaccine (as measured by the level of antibodies against Omicron BA.1). Moreover, the immune response to the original SARS-CoV-2 strain was comparable for both vaccines. The study involved more than 1,800 people, of which approximately 300 received Comirnaty Original/Omicron BA.1 in its final composition.

Further data from a study of over 600 people aged 18-55 who had previously received 3 doses of Comirnaty showed that the immune response to Omicron BA.1 was higher in those who received a booster with a vaccine containing only Omicron BA. 1 component than in those who received a booster with the original Comirnaty vaccine.

Based on these data, it was concluded that the immune response to Omicron BA.1 after a booster with Comirnaty Original/Omicron BA.1 in people aged 18-55 would be at least equal to that in people aged over 55 years old. based on previous data in younger people, it was also concluded that the immune response to a booster dose with Comirnaty Original/Omicron BA.1 in adolescents would be at least equal to that in adults.

Evidence supporting the use of Spikevax Bivalent Original/Omicron BA.1

Bivalent Spikevax Original/Omicron BA.1 can be used in adults and adolescents from 12 years of age, at least 3 months after the primary vaccination or a booster dose with a COVID-19 vaccine.

The CHMP opinion on Spikevax Bivalent Original/Omicron BA.1 is based on data from a study involving over 800 adults aged 18 years and over. The study found that a booster dose of bivalent Spikevax Original/Omicron BA.1 induced a stronger immune response against SARS-CoV-2 strain and Omicron BA.1 subvariant compared to a booster dose of the original Spikevax vaccine. The study compared the level of antibodies in people previously vaccinated with a primary series and a booster dose of Spikevax, and who received a second booster dose of Spikevax or bivalent Spikevax Original/Omicron BA.1. It was also concluded that Spikevax Bivalent Original/Omicron BA.1 could be used as a first booster after primary vaccination and that the immune response induced by a booster dose of Spikevax Bivalent Original/Omicron in adolescents aged 12-17 years would be at least equal to that of adults, since previous data with Spikevax showed a comparable effect.

How Adapted Vaccines Work

Adapted vaccines work in the same way as original vaccines.

Both suitable vaccines work by preparing the body to defend itself against COVID-19. Each vaccine contains molecules called mRNAs that have instructions for making the spike proteins of the original SARS-CoV-2 and the Omicron BA.1 subvariant. The spike protein is a protein on the surface of the virus that the virus needs to enter cells in the body and can differ between virus variants. By adapting the vaccines, the objective is to broaden the protection against the different variants.

When a person receives one of these vaccines, some of their cells read the mRNA instructions and temporarily produce the spike proteins. The person’s immune system will then recognize these proteins as foreign and activate the natural defenses – antibodies and T cells – against them.

If the vaccinated person later comes into contact with the virus, the immune system will recognize the spike protein on its surface and prepare to attack it. Antibodies and immune cells can protect against COVID-19 by working together to kill the virus, preventing its entry into body cells and destroying infected cells.

Vaccine mRNA molecules do not remain in the body but are degraded soon after vaccination.

Find out more about the procedures

The companies marketing Spikevax and Comirnaty have filed applications (known as variation applications) to modify the current marketing authorizations for the licensed vaccines Comirnaty and Spikevax to include the use of adapted vaccines. These applications included data on the quality and safety of suitable vaccines, and their ability to elicit immune responses against various strains of SARS-CoV-2.

The review was carried out by the EMA’s Committee for Medicinal Products for Human Use (CHMP), which is responsible for questions concerning medicinal products for human use. The CHMP opinion has been forwarded to the European Commission, which will make a final legally binding decision applicable in all EU member states.