- 40% of hospitalizations during BA.2 were vaccinated, boosted
- The weakening immunity and frequent mutations of Covid play their role
Nearly 40% of people hospitalized in the US with the subvariant of Covid that spread this spring were vaccinated and boosted, highlighting how new strains have mutated to more easily escape the immunity offered by current injections.
The findings of scientists from the US Centers for Disease Control and Prevention underscore the importance of Covid injections that better target the omicron subvariants.
Between late March and May, when the omikron BA.2 and BA.2.12.1 subvariants dominated the US, weekly hospitalizations increased for all adults — with those over 65 hit the hardest. Even so, the total number of hospitalizations remained much lower than when the delta variant ran rampant last fall.
The total number of hospitalizations is an important point, said Abraar Karan, an infectious disease physician at Stanford University.
"If you look at who is hospitalized, they are much more likely to be vaccinated because so many people are being vaccinated now," Karan said. "The real comparison is how many hospitalizations we have now versus in the past when people were unvaccinated or not up-to-date."
CDC researchers found that vaccines and boosters did a better job of keeping people with delta infections out of the hospital than vaccines with later variants. Efficacy decreased slightly with the BA.1 variant, then changed significantly with the BA.2 variant -- with a much higher proportion of hospitalized adults vaccinated with at least one booster.
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Immunity to vaccines begins to wane within six months, so staying up-to-date with shots is key to full protection. Less than half of Americans received a booster dose.
Adults with at least two boosters did better than other people when BA.2 was dominant. Most of those admitted to the hospital also had at least one underlying disease. Unvaccinated adults were more than three times more likely to be hospitalized, but breakthrough infections still accounted for a significant number of severe Covid cases, data shows.
U.S. regulators pressured Moderna Inc., Pfizer Inc. and BioNTech SE to accelerate the development of omicron-specific amplifiers for the September launch. Drugmakers this week submitted initial data to the US Food and Drug Administration to seek emergency approval for updated injections targeting the BA.4 and BA.5 strains of the virus. Scientists and vaccine manufacturers are already beginning to look at next-generation shots that can provide longer-lasting protection against multiple variants.
The new report's findings also suggest that along with vaccination, people at highest risk of contracting Covid should also use other pharmaceutical and non-pharmaceutical measures. This includes easy access to therapeutics such as Pfizer's antiviral drug Paxlovid and Gilead Sciences' remdesivir, as well as AstraZeneca's Evusheld for people with weakened immune systems. The researchers also note that wearing a mask may help protect the wearer from disease.
Omicron
Just when it seemed the world was finally fighting the Delta variant of the coronavirus with vaccines and vaccinations, a new strain of COVID-19 appeared — Omicron.
Omicron (B.1.1.529), named as one of the most transmissible variants of the coronavirus, was initially identified in patients in Botswana and South Africa in early December 2021.
Although it is not yet clear whether this variant is more severe than the Delta variant, the WHO Technical Advisory Group on Virus Evolution (TAG-VE) has argued that this variant has more mutations and can thus easily spread worldwide.
As cases increase worldwide, WION brings you the latest updates on Omicron variants from around the world. From lockdowns to travel restrictions to symptoms, vaccines and medicines, WION will keep you updated with Omicron updates from around the world and India.
