Research showed that people who received two doses of the mRNA-based Pfizer-BioNTech or Moderna vaccine enjoyed significant protection against symptomatic disease caused by BA.1 or BA.2 for several months.
The ‘stealth Omicron’, a subline of the Omicron BA.1 variant, is causing the worst Covid outbreak in China and South Korea since 2020 and prompts Indian health experts to be alert to the approaching fourth wave of the coronavirus pandemic in the country. However, too much delay, a new study says the mRNA vaccines may protect against Omicron BA.2 but its effects against symptomatic waves of disease within months of a third dose.
India’s first mRNA-based Covid vaccine is being developed by Pune-based Gennova Biopharmaceuticals, which recently submitted Phase II and Phase III study data to the regulatory agency Drugs Controller General of India (DGCI), sources said. .
Several studies have already established that BA.2 spreads faster than BA.1 Omicron variant, but it is still not clear whether the stealth variant is better at evading the immunity provided by Covid-19 vaccines . But this too-peer-reviewed study, published on the preprint server medRxiv, showed that people who received two doses of the mRNA-based Pfizer-BioNTech or Moderna vaccine enjoyed substantial protection for several months against symptomatic disease caused by BA. .1 or BA.2.
However, protection decreased to about 10 percent after 4-6 months of the third vaccination. This means that after 4-6 months of infection, the vaccine can only prevent infection in 10 percent of cases. The protection afforded by the vaccines similarly decreases for both the variant lines and with a different booster dose, 30-60 percent protection can be achieved again for both BA.1 and BA.2
Surveillance data collected in the UK also show comparable results of protection by vaccine restriction to less than 20 percent for both subvariants at 15 weeks or more from the day of the second dose and after the third dose it increases to approximately 70 percent 2 – 4 weeks after the injection.
According to Laith Abu-Raddad, an infectious disease epidemiologist at Weill Cornell Medicine-Qatar in Doha and co-author of the study, BA.2 was previously thought to be more dangerous than BA.1, but the study results now give him hope that vaccines and booster doses can prevent the worst cases of Covid even for the new stealth variants.
This post Omicron BA.2: mRNA-based vaccines provide protection that diminishes over time, says UK study was original published at “https://www.financialexpress.com/lifestyle/health/omicron-ba-2-mrna-based-vaccines-give-protection-that-wanes-with-time-says-uk-based-study/2466671/”
