How well does the adapted Covid-19 vaccine protect?

Divided:

06.12.2022 12:59

How well does the adapted Covid-19 vaccine protect?

BA.5 Adapted Vaccine Enhances Antibody Response, New Omicron Subvariants Still Show Strong Immune Escape

Should I get boosters again? And if so, with which vaccine? Many citizens who have received the basic immunization, which usually consists of three individual vaccinations, ask themselves these questions. A team of researchers from the German Primate Center – Leibniz Institute for Primate Research in Göttingen and the Hannover Medical School examined the antibody-mediated neutralization of the SARS-CoV-2 variants after the fourth vaccination (booster) and compared the vaccine variants. Their results showed that revaccination enhances the neutralization of SARS-CoV-2. Comparison of samples from those vaccinated with a vaccine matching BA.5 and those who received an incompatible vaccine showed that the vaccine matching BA.5 produced slightly better neutralization. However, the currently circulating variants BA.2.75.2 and BQ.1.1 showed pronounced antibody flight and were only weakly inhibited after booster vaccination. These results clarify that a booster vaccination is generally helpful, but only reduced protection against BA.2.75.2 and BQ.1.1 (The Lancet Infectious Diseases) can be expected.

SARS-CoV-2 infections still lead to many hospital admissions worldwide. Vaccinations protect against serious illnesses, among other things by triggering the formation of neutralizing antibodies. However, some SARS-CoV-2 variants can partially evade antibody-mediated neutralization. This is called the flight of antibodies. In particular, the omicron variant carries numerous mutations in the spike protein that reduce the inhibition of the virus by neutralizing the antibodies. Therefore, vaccines have been adapted to provide better protection against omicron subvariants. However, the question of whether adapted vaccines actually work better than non-adapted “classical” vaccines was open. Furthermore, information was previously lacking on how strongly the recently emerged omicron subvariants BA.2.75.2 and BQ.1.1 evade neutralizing antibodies. Researchers from the German Primate Center’s Department of Infection Biology, together with researchers from Hannover Medical School, measured the ability of antibodies present in the blood of vaccinated people to neutralize various subvariants of omicrons.

The results show that blood from primed individuals who received an additional booster vaccination (i.e. fourth vaccination) has higher neutralizing activity against omicron subvariants than blood from primed individuals without a booster vaccination. Neutralization of the omicron subvariant after using a vaccine adapted to the omicron subvariant BA.5 for booster vaccination was slightly better than after using the non-adapted classical vaccine. “In our study, although increased neutralizing activity was observed after immunization with the BA.5-adapted booster vaccine, the difference compared to the non-adapted classic vaccine was minimal. In this context, however, it should be noted that we considered a period immediately after booster immunisation. It is therefore possible that more significant differences occur at a later point in time, for example due to advanced antibody maturation,” says Markus Hoffmann, first author of the study.

In their investigations, the researchers also found that nearly all people who received a booster vaccination had neutralizing antibodies against the SARS-CoV-2 BA.5 variant that circulated in the summer. Conversely, neutralizing antibodies against BA.2.75.2 and BQ.1.1 were not detected in some of the vaccinated subjects. “The omicron subvariants BA.2.75.2 and BQ.1.1 show strong antibody escape and it can be assumed that these variants can cause infections with a symptomatic course in some patients despite booster vaccination,” says Stefan Pöhlmann, Head of the Department of Infection Biology at the German Primate Center, and adds: “Samples from core immunized individuals with breakthrough infection during the first omicron wave in spring 2022 and additional booster vaccination with the BA.5-adapted vaccine showed antibodies that each of the tested variants neutralized efficiently and should therefore provide strong protection against further infection with omicron subvariants.”

“Our study shows that a booster vaccination generally makes sense to increase neutralizing activity against new virus variants. Even though BA.2.75.2 and BQ.1.1 can largely evade inhibition by neutralizing antibodies, one can still expect partial protection against these variants, including through the T-cell-mediated immune response, which our study did not explicitly address, says Markus Hoffmann.

Scientific contacts:

Prof. Dr. Stefan Pöhlmann
Telephone: +49 551 3851-150
Email: [email protected]

Dr Markus Hoffman
Telephone: +49 551 3851-338
Email: [email protected]

Original publication:

Hoffmann M, Behrens GMN, Arora P, Kempf A, Nehlmeier I, Cossmann A, Manthey L, Dopfer-Jablonka A, Pöhlmann S (online): Effect of hybrid immunity and bivalent booster vaccination on omicron sublineage neutralization . The Lancet Infectious Diseases doi.org/10.1016/S1473-3099(22)00792-7