Two new vaccines targeting the Omicron variant of Covid have been validated by the European Medicines Agency for use from this fall. One from Pfizer. The other from Moderna. For whom in France? When ? What do they contain? Discovery.
Two new vaccines targeting the Omicron variant of Covid have been validated by the European Medicines Agency (EMA) on September 1, 2022 for a use from autumn 2022. One of Pfizer. The other of Moderna. Both are to be used as reminders or “boosters”, not in primary vaccination. France has not yet communicated on the modalities of vaccination with these vaccines. “Exposing the immune system to contemporary versions of the virus so that it learns and recognizes later variants is essential for developing a broader immune response“ explains the EMA in a communicated of September 6. The EMA is also evaluating a vaccine adapted to the original strain and to the Omicron BA.4 and BA.5 subvariants. She also initiates the idea of a “booster vaccination at the start of the winter season as for the flu”.
What are the new Covid vaccines against Omicron?
These vaccines are adapted versions of the original Comirnaty vaccines (Pfizer/BioNTech) and Spikevax (Moderna) to target the Omicron BA.1 subvariant in addition to the original SARS-CoV-2 strain. They work the same way. Each vaccine contains mRNA molecules (messenger RNA) who have instructions for make the spike proteins of SARS-CoV-2 original and the Omicron BA.1 subvariant. The spike protein is a protein on the surface of the virus that the virus needs to enter body cells and may differ between variants of the virus. 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 then recognizes these proteins as foreign and activates natural defenses – antibodies and T lymphocytes – against them. If the vaccinated person later comes into contact with the virus, the immune system recognizes the spike protein on its surface and prepares 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.
What is the name of the new Covid vaccines?
For now, in press releases, Pfizer has referred to its new vaccine as “Comirnaty® Original/Omicron BA.1” and Moderna by “Spikevax® Bivalent Original/Omicron BA.1 (mRNA-1273.214)“.
What is Pfizer’s new Omicron Covid vaccine?
The new vaccine developed by the American laboratory Pfizer-BioNTech targets the BA.1 Omicron sub-lineage. It is based on its original Covid vaccine, Comirnaty. He contains 15 µg of mRNA coding for the SARS-CoV-2 spike protein, which is present in the original Pfizer vaccine and 15 µg of mRNA encoding the Omicron BA.1 subvariant protein spike. Apart from the addition of the BA.1 spike protein mRNA sequence, all other components of the vaccine remain unchanged. Two studies have enabled its validation :
► a study conducted in 1,800 adults over 55 who had previously received 3 doses of Comirnaty (primary and booster) of which approximately 300 received Comirnaty Original/Omicron BA.1 revealed 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.
► a study covering more than 600 people aged 18 to 55 who had previously received 3 doses of Comirnaty showed that the immune response to Omicron BA.1 was higher in people who had received a booster with a vaccine containing only Omicron BA. 1 than in those who received a booster with the original Comirnaty vaccine.
What is Moderna’s new Covid Omicron vaccine?
The new vaccine developed by the American laboratory Moderna targets the BA.1 Omicron sub-lineage. It contains 25 µg of the currently authorized booster (Spikevax/mRNA-1273) and 25 µg of an Omicron subvariant. A study has enabled its validation. She wore on more than 800 adults aged 18 and over. The study revealed 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.
Who should make the new Covid vaccine?
These two new Covid vaccines are authorized in people aged 12 and over who have received at least one primary vaccination course against Covid-19, regardless of the vaccines used at the time. However, the European Center for Disease Prevention and Control (ECDC) and the European Medicines Agency recommend addressing “Priority to those most at risk of developing a serious illness”. Concretely :
- people aged 60 and over,
- immunocompromised and other vulnerable people (from 12 years old) with underlying conditions putting them at higher risk of severe Covid-19,
- pregnant women
- residents and staff of long-term care homes
- health professionals.
“As these new vaccines are approved for use only as booster doses, the original vaccines remain essential to increase vaccination coverage with a primary series among unvaccinated people to fill the vaccination gap” said ECDC Director Dr Andrea Ammon.
When to do this new vaccine booster?
According to the EMA, it will take wait 3 to 4 months after their last dose of vaccine or Covid infection to receive this new reminder.
They also cover protection against BA.5 and the Centaur variant.
How effective are these vaccines against Omicron?
Pfizer and Moderna have updated their primary vaccines to deploy these boosters against Omicron. They target the BA.1 sub-lineage (present at the beginning of 2022 above all) but “preliminary data indicate that the immune response induced by vaccines adapted to BA.1 goes beyond the selected strains and covers other Omicron sub-variants such as BA.2, BA.2.75 (centaur variant, editor’s note ) and BA.5, more effectively than current vaccines”.
What side effects?
Side effects observed with vaccines targeting Omicron were “comparable to those seen with the original vaccines and were generally mild and short-lived” indicates the EMA.
Sources
ECDC-EMA statement on booster vaccination with Omicron adapted bivalent COVID-19 vaccines. EMA. September 6, 2022.
Pfizer and BioNTech Receive Positive CHMP Opinion for Omicron BA.1-Adapted Bivalent COVID-19 Vaccine Booster in European Union. Pfizer, September 1, 2022
EMA CHMP adopts positive opinion recommending authorization for the use of Moderna’s Omicron-Targeting Bivalent Booster in the European Union, Moderna, September 1, 2022.