Researchers at the Karolinska Institutet and Danderyd Hospital have found that the latest COVID-19 vaccine against the Omicron variant significantly increases antibody levels against various SARS-CoV-2 strains. The findings, part of the COMMUNITY study, show increased protection against new variants, underscoring the importance of vaccines for high-risk groups.

A new study reveals a strong response to an updated COVID-19 vaccine against Omicron and other SARS-CoV-2 variants, suggesting the vaccine is broadly protective and underscoring its importance in susceptible populations.

Researchers at the Karolinska Institutet and Danderyd Hospital followed recipients of the new updated COVID-19 vaccine and analyzed their antibody responses to different SARS-CoV-2 variants. The results showed that the antibody response to the highly mutated Omicron variant that is currently dominant was surprisingly strong.

The ongoing "community" study was launched in spring 2020, with 2,149 staff at Dandelion Hospital being tested regularly. The study recorded a total of 24 participants, most of whom were over 64 and had been vaccinated four or five times.

Previous updates of COVID-19 vaccines included the original SARS-CoV-2 variant and Omicron. However, they elicit much stronger antibody responses to the former than to the latter. Omicron variants currently dominate the world, and the dramatic increase in OmicronXBB variants and their subvariants has prompted the development of vaccines against these strains. However, other variants have caught up, including the highly mutated BA.2.86, and scientists have been unsure whether the new vaccine can protect against these variants as well.

Now, the findings show that newer COVID-19 vaccines not only increase antibodies against XBB tenfold, but also against newer, more mutated strains like BA.2.86.

"It's great to see that the new updated vaccine induces such a broad antibody response," said Charlotte Thålin, researcher at the Department of Clinical Sciences at Karolinska Institutet, MD, Danderyd Hospital, and principal investigator of the COMMUNITY study. "Previous updates were unable to make people respond to Omicron and the new variants because they had adapted to the original virus. The broad response we are seeing now is most likely due to the fact that the new vaccine only targets Omicron that is very different from the original virus."

Ulrika Marking, first author of the paper and a doctoral student at the Department of Clinical Sciences at Karolinska Institutet, said: "We saw a larger rise in neutralizing antibodies against all the new variants we tested than we expected. This is a strong indication that the new vaccine also provides cross-protection against new variants and confirms the recommendation that older people and people at high risk from influenza and COVID-19 should be vaccinated."

Compiled from /ScitechDaily