A previous infection with Covid provided protection more “durable” against infection with the Omicron variant than two or three doses of Pfizer or Moderna vaccines, but the protection was stronger after vaccination and a previous infection, according to a study published in New England Journal of Medicine Wednesday (15), highlighting the benefits of vaccination for all amid a further increase in cases.
A previous Covid infection halved the risk of symptomatic reinfection with Ômicron, according to the peer-reviewed study, which analyzed health data for the entire population of Qatar (2.9 million people) between December 2021 and February 2022.
Reinfection protection was “moderate and long-lasting,” the researchers said, and the result was roughly the same for Omicron BA.1 and BA.2 subvariants. Protection after vaccination disappeared “quickly,” the researchers said, and was “negligible” after the primary vaccination (two doses of the Pfizer or Moderna mRNA vaccine) and about 60% after the vaccination. reinforcement, although the researchers noted that most of the people studied had taken the second dose more than six months ago and the third dose in the last 45 days.
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Hybrid immunity after vaccination and infection offered the best protection against reinfection, approximately 50% after primary vaccination and almost 80% after reinforcement. The findings highlight the “benefit of vaccination” even for those with a previous infection. Although protection varied significantly, the researchers emphasized that prior infection, vaccination, and hybrid immunity transmitted an equally high degree of protection (about 70 percent) against serious or fatal disease.
The finding is in line with a growing body of research that sheds light on the strong protective benefits that occur after vaccination and infection. Highlight the benefits of getting vaccinated even if you have already had Covid-19. It also highlights the transient nature of some aspects of vaccine protection, which has become especially notable as the highly infectious Omicron variant has emerged worldwide, regardless of vaccine coverage.
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Experts do not fully understand why natural infection provides more lasting immunity, and this may change depending on the variant with which a person becomes infected. This study would also cover infected people with predominant variants before the Omicron wave hit Qatar.
Scientists and public health officials are now trying to understand how to reproduce this more lasting natural immunity as they prepare the next generation of vaccines for early booster campaigns and face a new wave of Omicron subvariants (BA.4 and BA.5 ) who are winning. land, in the United States and in Europe. Evidence suggests that, unlike previous variants, Omicron infection may not provide much protection against subsequent infections.
The researchers noted that the degree of protection of hybrid immunity after reinforcement it appeared to have two separate layers, as if protection against infection and vaccination acted independently rather than synergistically or through a similar mechanism. This was also observed among people who had been previously infected and vaccinated but had not been given a booster dose, and who had a similar level of protection to people who had just had a past infection (suggesting that protection from primary vaccination decreased over time). The “impressive” finding “needs more research” to better understand how the two forms of immunity interact, the researchers added.