- It is what the scientific and medical community has called "hybrid immunity"
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| What is "hybrid immunity" against Covid and what kind of protection does it offer? / Pexels |
The new recombinant variant XE of Covid-19 has already been reported in Spain, after being detected for the first time in January in the United Kingdom. It is a mutation arising from two omicron sublineages (BA.1 and BA.2) that share the spike gene.
However, from the scientific community, they emphasize that it is "quite foreseeable" that it does not suppose a reason for alert, nor a new turn in the current epidemiological situation, due to the high rates of vaccination among the population and the high percentage of immunity against other variants.
What is it and why is it good news?
In this sense, what is the so-called "hybrid immunity"? What do people with this type of immunity have in common? Two studies have shown that those who have received the complete vaccination schedule and who had previously been infected have stronger protection against this virus.
It is what the scientific and medical community has called "hybrid immunity", which is the combination of being vaccinated and having passed the disease naturally. According to both studies, this situation could provide good long-term protection, even against new variants.
One of the two studies analyzed data from more than 200,000 people in 2020 and 2021 in Brazil. The results revealed that for people who had had the disease, the Pfizer and AstraZeneca serum was 90% effective against hospitalization and death.
Another study, using the Swedish national registry up to October 2021, found that people who recovered from Covid maintained a high level of protection against reinfection for up to 20 months. Likewise, people with hybrid immunity from two doses of vaccines had a 66% lower risk of reinfection than those with natural immunity.
Why does this happen?
"More than 35 studies have shown that hybrid immunity offers broad and complementary protection. This is because the immunity of the vaccines targets the spike protein, after which the Covid-19 vaccines were designed, and the infection-induced immunity targets the entire virus more broadly," explains Katelyn Jetelina, epidemiologist and professor in the School of Public Health at the University of Texas Health Science Center, in an article for The Conversation.
In reference to the administration of a fourth dose, the expert in epidemiology maintains that there is "strong evidence that a fourth dose or a second booster provides significant protection among vulnerable populations."