Vaccination plus disease provide better protection against mutations

People who have been infected with both coronavirus and subsequently vaccinated have better quality antibodies to the newer variants that cause Covid-19 and thus have more effective protection against those who have just been either vaccinated or infected with the virus, according to a new US scientific study.

The researchers, led by immunologist Dr. Otto Young of the University of California, Los Angeles (UCLA) School of Medicine, who published the study in the American Society for Microbiology mBio, noted that "not all antibodies are the same." For example, those who became ill at the beginning of the pandemic and later developed antibodies or those who received a vaccine months ago may not be able to prevent an infection from a new strain of the coronavirus, such as e.g. the Omicron variant. However, those who have "hybrid" immunity, because in the past they both got sick and were vaccinated, are in a comparatively better position.

"Not only the quantity but also the quality of the antibodies can improve over time," Yang said. As he said, as the pandemic develops and new strains of the coronavirus emerge, the antibodies that someone has from an older infection may not adequately protect them against a newer variant of the virus.

The new study, which analyzed blood samples from people who had previously been ill with Covid-19 (before May 2020), confirmed that their antibodies have reduced efficacy against subsequent variants. But when these people were vaccinated after one year, their antibodies were of better quality and were just as effective against the most recent coronavirus strains.

"We predicted that the antibodies would continue to evolve and get better after multiple exposures to the virus, but we did not expect this to happen so quickly," Yang said.

Source: RES - EIA