A new study published in the scientific journal Nature communications indicates that when a Covid vaccine combines different variants of the virus, it can offer greater protection against those currently in circulation, but also against those that may appear in the future.
Exposure to different variants causes the neutralizing (infection fighting) antibody response to be different, greater “robust”.
Since when the virus was identified in 2020, New variants have been discovered as the genetic code of this pathogen evolves. Some spread more easily, are more virulent, or evade vaccines more effectively. These are known as “variants of concern”.
Antonia Netzl, A PhD student at the University of Cambridge, he collaborated with scientists from that center and from the University of Innsbruck (Austria), analyzed data on the immune response to different variants and vaccines. With this data, they created ‘antigenic maps’ and ‘antibody landscapes’ to explore their differences.
Since it appeared in December 2021, the omicron variant has been one of those of concern to the authorities. This variant in turn has several lineages (BA.1, BA.2, BA.4, BA.5 and BA.2.12.1), among which the BA.5 ended up being the dominant one in many countries, only to be supplanted by others.
Netzl and his collaborators observed, in their “maps,” that omicron is not only immunologically different from the alpha and delta variants, but that their subvariants, or lineages, also exhibit important differences from each other. Antibody landscapes, a way to illustrate the immunological profile of patients, allowed the researchers to see how the vaccine or infection with different variants increased the ability to neutralize viruses.
The researcher said: ‘We found that people exposed to BA.1 were better protected against BA.2, but this mechanism didn’t work in reverse.’ The good news, in his words, is that “we have also seen that there are two types of exposure – for example, vaccination and infection with a different variant – which increase the levels of antibodies against all variants. As a result, people who received a vaccine and became infected with the delta variant, for example, were better protected against omicron than those who were only vaccinated or only infected.
For the expert, this suggests that an update of the vaccine, with a different variant, would be beneficial in terms of greater protection against all circulating variants, and also for the unknown ones. “The bivalent vaccines with the original prototype and an omicron variant in a single dose, protect more,” he said.
These results have been confirmed by clinical studies with bivalent vaccines. Although infection with multiple variants has similar effects, Netzl points out that vaccines offer effective protection and reduce the severity of the disease caused by the coronavirus.
“The population should be vaccinated, even if they have overcome the disease; Vaccination is important to strengthen the immune response, reduce the risk of infection and the severity of symptoms,” she recalled. Their work, together with the results of trials of combination vaccines and information gathered in clinical practice, provides a ‘robust’ foundation for the development and design of future vaccines.
