Why did so many vaccinated people catch the omicron variant recently ?

Many people report that they have seen many of their friends and family and work colleagues have caught the COVID virus during the recent wave.

Why did so many vaccinated people catch the infection?

It’s because of two reasons. (1) the vaccines are not 100% effective and (2) there is substantial reduction in vaccines effectiveness over time.

A large U.K. study looked at vaccine effectiveness against symptomatic disease caused by the omicron and delta variants in England.

Frighteningly, No effect against the omicron variant was noted from 20 weeks after two Astra Zeneca vaccine doses, and the effectiveness of two Pfizer vaccine was only marginally better with 8.8% protection at 25 or more weeks after two Vaccine doses.

Vaccine effectiveness improved to about 65% protection at 2 to 4 weeks after a third Pfizer booster but this was not long lasting and the effectiveness decreased to about before decreasing to 44% at 10 or more weeks after Vaccination.

In summary, Vaccination with two doses of AstraZeneca or Pfizer vaccine provided limited protection against symptomatic disease caused by the omicron variant.

A third booster with Pfizer or Moderna vaccine substantially increased the protection, but even that protection gradually decreased over time.

This study, published in the Prestigious NEJM journal, was Funded by the U.K. Health Security Agency and hence highly reliable.

One has to hope that any new variants do not bypass the vaccine protection and cause much more severe disease than omicron!


Daily Mail. US Omicron surge is close to reaching its peak with infections ‘coming down as fast as they went up as variant runs out of people to infect’: Deaths remain low, rising just 10% in two weeks as daily cases rise 184%. By Mansur Shaheen U.S. Deputy Health Editor For Dailymail.Com
14:53, 12 Jan 2022 , updated 22:18, 12 Jan 2022

NEJM. Covid-19 Vaccine Effectiveness against the Omicron (B.1.1.529) Variant.

Nature magazine. Iketani, S., Liu, L., Guo, Y. et al. Antibody evasion properties of SARS-CoV-2 Omicron sublineages. Nature (2022). https://doi.org/10.1038/s41586-022-04594-4 ( substantial loss in neutralizing activity against omicron variant)

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