COVID-19 vaccine booster protection against Omicron fades within 10 weeks, says new study

In a more concerning development, efficacy of mRNA Pfizer’s booster shot against symptomatic COVID-19 infection from Omicron variant waned in just 10 weeks after third shot, a new study has found this week. As highly complex strain with more than 65 mutations and 32 mutations on spike protein has been spreing like wildfire, pushing cases of coronavirus to more than 100,000 for first time since pandemic hit in UK, scientists and health experts have been weighing into protection vaccines provided against this hyper transmissible variant.

Unlike COVID-19 caused by or variants, Omicron has been showing unique symptoms among patients along with usual "high temperature, a new, continuous cough, or a loss or change to a sense of smell or taste” noticed in case of Delta. Those who contracted Omicron also noted several or symptoms which aren't usually associated with coronavirus, such as nausea and a loss of appetite.

Immunity offered by boosters 'wanes more quickly'

But more worryingly, Britain’s Health Security Agency outlined surveillance analyses related to risk assessments of B.1.1.529. It stressed that immunity offered by vaccines wanes more quickly with omicron than was previously seen in any or variant including SARS-CoV-2. “ protection conferred by booster vaccines against omicron variant begins to wane within 10 weeks,” according to technical briefing released by UK Health Security Agency (UKHSA). British agency’s analysis was based on research of 147,597 Delta and 68,489 Omicron cases. Researchers shockingly found that Oxford/AstraZeneca, Pfizer/BioNTech, and Moderna COVID-19 vaccines are less effective against Omicron than Delta.

“re is evidence of waning of protection against symptomatic disease with increasing time after dose 2, and by 10 weeks after booster dose, with a 15 to 25% reduction in vaccine effectiveness after 10 weeks,” UKHSA said.

“This waning is faster for Omicron than for Delta infections. re are insufficient severe cases of Omicron as yet to analyze vaccine effectiveness against hospitalisation.” 

For those who received 2 shots of Oxford/AstraZeneca vaccine,  third booster shot of Pfizer/BioNTech or Moderna will only be 60% effective at preventing symptomatic COVID-19 infection 2 to 4 weeks after third booster dose. But this protection fes to just 35% to 45%  by 10 weeks. And those who received two initial doses of Pfizer/BioNTech, protection against Omicron falls from 70% at 2 to 4 weeks to 45% at 10 weeks after y take a Pfizer booster shot. protection however falls to 70% to 75% by 9th week after a Moderna booster shot. 

Some Omicron cases 'third' episode of reinfection

UKHSA report also estimates that those infected with B.1.1.529 variant may be 50% less likely to be mitted to hospital, while a separate study published by Imperial College London found risk was 15 to 20% lower compared to Delta. vulnerable population or those with comorbidity may however face more serious COVID-19 and refore health safety precautions are recommended.

reinfection rate has increased sharply and disproportionately with Omicron, as per UK agency. re are 69 identified cases with Omicron which are a “third” episode of infection, at least 290 cases of Omicron infection were recovered COVID-19 cases between a 60 to an 89-day interval of recovery period. 

Britain’s Health Security Agency categorically stresses that to avoid similar levels of hospital mission witnessed during Delta wave, Omicron B.1.1.529 strain will have to be 90% less severe than all strains previously detected. But rate of spre of new variant is dramatically worrying and risks overwhelming hospitals, UK government’s Scientific visory Group for Emergencies stated in study.

“What we have got now is a really fine balance between something that looks like a lower risk of hospitalization – which is great news – but equally a highly transmissible variant and one that we know eves some of our immune defenses, so it is a very balanced position,” Jenny Harris, chief executive of UKHSA, told  Today programme, BBC Rio 4.

Just yesterday, UK has recorded 119,789 new cases of COVID-19 shattering all records of previous several months. UK’s Office for National Statistics estimates that 1.4 million people have contracted COVID-19 this week. This is highest yet comparable figure that was recorded in autumn 2020 during initial pandemic waves. “Omicron has continued to increase sharply as a proportion of cases in England, it is predominant in all regions of England,” UK agency stressed. “ increase is also visible in wastewater, particularly in London and South East,” it ded. While Omicron has been behind large community transmission, relative to Delta, it is currently more concentrated in young ult age groups between 20 to 29, UKHSA warned. London, thus far as per data until Dec. 20 has seen 40% hospitalizations from Omicron variant. 

Of those hospitalized in London, 17 (12.9%) h received a booster dose, 74 (56.1%) a second dose, and 27 (20.5%) were not vaccinated (less than 10 were unlinked or h one dose). At least 14 people died within 28 days of an Omicron diagnosis, age range 52 to 96 years. risk of hospital mission for a person detected as a case of Omicron appears reduced compared to a case of Delta. But this analysis is preliminary because of small numbers of Omicron cases currently in hospital, and limited spre of Omicron worldwide as variant is in initial stages of transmission and has not reached older age groups as yet, UKHSA noted.