An infection with Omicron does not offer substantial immunity against other Covid-19 types without immunisation, according to a study. Researchers from Gladstone Institutes and UC San Francisco (UCSF) in the United States found that the Omicron variant elicits just a mild immune response in mice and blood samples from infected donors.
This response, while limited, helped increase overall protection against a number of Covid strains in vaccinated people. The immune response failed to give widespread, strong protection against other strains among people who had not previously been vaccinated, according to a study published in the journal Nature. "An infection with Omicron might be roughly similar to obtaining one shot of a vaccine in the unvaccinated population," Melanie Ott, director of the Gladstone Institute of Virology, stated.
It provides some protection against Covid-19, but it isn't particularly wide," Ott explained. Despite the milder symptoms, the immune system in Omicron-infected mice nonetheless produced T cells and antibodies similar to those seen in other viruses, according to the researchers.
The researchers also collected blood samples from mice infected with the ancestral, Delta, or Omicron variants of SARS-CoV-2 and measured the ability of their immune cells and antibodies to recognise five different viral variants - ancestral (WA1), Alpha, Beta, Delta, and Omicron - to see how the immune response to Omicron changed over time.