New Covid vaccines: bivalent, Omicron, what is it, for whom?

New Covid vaccines bivalent Omicron what is it for whom

NEW OMICRON COVID VACCINE. Three new bivalent vaccines targeting the Omicron variant of Covid (including BA5) are validated in France on September 20. They should be used as a priority for people at risk who need to take a booster dose.

[Mise à jour le 20 septembre 2022 à 18h35] Three new vaccines targeting the so-called “bivalent” Covid Omicron variant have been validated in France by the High Authority of Health September 20: two Pfizer vaccines (one targets the BA1 Omicron lineage, the other targets BA4 and BA5) and a Moderna vaccine targeting BA1. These three vaccines are reserved for booster use (3rd or 4th dose) for the people at risk of serious forms of Covid. They cannot be used as a first vaccination against Covid. They have been validated by the European Medicines Agency (EMA) on September 1. “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 explained theEMA. The HAS underlines, it, “the interest of link this new campaign (booster vaccination) to that of vaccination against the seasonal flu which will start on October 18.

What are the new Covid vaccines against Omicron?

The three new Covid vaccines authorized in France in September 2022 are variations of the Covid vaccines from the Pfizer and Moderna laboratories:

  • Comirnaty Original/Omicron BA.1
  • Comirnaty Original/Omicron BA.4-5
  • Bivalent Spikevax Original/ Omicron BA.1.

These vaccines are adapted versions of the original Comirnaty vaccines (Pfizer/BioNTech) and Spikevax (Modern) for target Omicron’s BA1, BA4 and BA5 sublines in addition to the original SARS-CoV-2 strain. That’s why they say “bivalent“while the vaccines used in primary vaccination are said to be “monovalent” because they only target the original strain of the virus. The new vaccines have the same principle of action: each contains mRNA (messenger RNA) molecules who have instructions for make the spike proteins of SARS-CoV-2 original and of the Omicron BA.1 or BA4-BA5 sub-variant. 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 the moment, the High Authority of Health has designated the new vaccines under the names: Comirnaty Original/Omicron BA.1, Comirnaty Original/Omicron BA.4-5, Bivalent Spikevax Original/ Omicron BA.1.

What is Pfizer’s new Covid vaccine?

Two new vaccines developed by the American laboratory Pfizer-BioNTech target for one the BA.1 Omicron sub-lineage and for the other the BA4-BA5 sub-lineages. They are based on the original Covid vaccine, Comirnaty. They contain 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 coding for the protein spike of the Omicron BA.1 subvariant or BA4/BA5. Other than the addition of the spike protein mRNA sequence, all other components of the vaccine remain unchanged.

What is Moderna’s new Covid 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 be vaccinated with the new Covid vaccines?

These 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. They are authorized for a booster dose. The two population groups to be targeted for this additional dose of vaccine according to HAS recommendations are:

  • people over 60 and adults under 60 at risk of severe disease :
  • those who have comorbidities that expose them to these severe forms,
  • pregnant women, from the 1st trimester of their pregnancy,
  • immunocompromised people regardless of age,
  • children and adolescents at high risk suffering from pathologies justifying it.
  • the entourage of these people (cocooning strategy) as well as the people who are in regular contact with them:
  • professionals in the health and medico-social sector.

For people under 30it maintains its recommendation to only use Comirnaty® vaccines (Pfizer BioNTech).

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 new vaccines against Omicron?

“The expected clinical efficacy for these new bivalent vaccines is at least equivalent or even superior to that of the original vaccines monovalent, without this probable superiority being able to be currently demonstrated in real life” indicated the HAS in its press release of September 20.

What side effects?

The tolerance of these vaccines “is identical to that of monovalent vaccines” informs the HAS. 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

Covid-19: HAS includes bivalent vaccines in the vaccination strategy for the fall. Press release, September 20, 2022

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.

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