COVID-19 Vaccines Effective Against Omicron Subvariants [Reading Science]

Qatar Research Team Reports Study Showing Protection Lasts 4-6 Months After Second Dose Then Rapidly Declines

[Asia Economy Reporter Kim Bong-su] Research results have shown that existing COVID-19 vaccines such as Moderna and Pfizer provide a short-term defense against not only Omicron but also its subvariant, Stealth Omicron. As Stealth Omicron is replacing its sister variant Omicron worldwide, the findings that existing vaccines have some effectiveness have alleviated concerns about the acceleration of re-spread.

The research team from Weill Cornell Medicine in Doha, Qatar, analyzed the treatment status of COVID-19 Omicron and Stealth Omicron variant infections using the Qatari government's medical information system on the 13th, and published the related paper recently on the medical preprint site 'medRxiv'.

In the paper, the team stated that people who received two doses of Pfizer or Moderna vaccines were confirmed to have significant protection against both Omicron and Stealth Omicron. However, this protection rapidly decreased to around 10% after 4 to 6 months post-vaccination. The rate of decline was similar for both variants. Additionally, a third dose restored protection against the two variants to approximately 30-60%.

The mRNA vaccines' effectiveness in preventing severe illness was also demonstrated. The Qatar research team confirmed that even with only two doses, the prevention rate of severe illness was over 68% for at least seven months, and for those with a third dose, it prevented severe illness at a rate exceeding 80%.

Abu Raad from the Qatar research team said, "The existing vaccines provide hopeful results by showing high effectiveness in preventing severe illness from Stealth Omicron as well," adding, "Despite the evolution of the COVID-19 viruses, the vaccines are surprisingly working well."

Meanwhile, the UK Health Security Agency also announced a similar conclusion on the 17th based on data collected so far. They reported that protection against the two variants drops below 20% after more than 25 months following the second vaccine dose, but rises to the 70% range 2 to 4 months after the third dose.