COVID-19 booster dose more than 90% effective against Delta & Omicron variants: US' CDC

In its latest three researches on COVID-19, the US Centers for Disease Control and Prevention (CDC) found that the booster is more than 90% effective against both the Delta and Omicron variants. As per the findings of the latest studies, the Pfizer and Moderna's vaccines third dose offer improved protection against hospitalisations due to COVID-19 variants. The data reveals that vaccine effectiveness against hospitalisation after two doses of vaccine was 90% for next six months but reduced to 81% later.  

The findings, which were announced on Friday, pose the question of whether individuals who have received only two COVID-19 vaccine doses are still adequately immunised, CNN reported. Previous research, which includes studies from Germany, South Africa, as well as the United Kingdom, have discovered that the available vaccines are considered to be less efficient against the highly contagious Omicron than earlier variants of the coronavirus, however, it also showed that booster doses enhance virus-fighting antibodies, increasing the likelihood of avoiding symptomatic infection. But now, the recent research has revealed that a third dose of the BioNTech-Pfizer and Moderna COVID-19 vaccines have the most effective strategy to guard against the newest variants.  

CDC conducted 3 new studies  

The first research has looked into the hospitalisation, emergency department, and urgent care centre visits in ten states from August 2021 until this month. It has been discovered that three doses of the Pfizer or Moderna vaccines were most beneficial in avoiding COVID-19-related emergency department as well as urgent care visits. 

Further, During the Delta wave, protection declined to 94%, while, in the case of Omicron, it showed 82%. Only two doses provided less protection, particularly if six months had gone since the second dosage, AP reported. On that front, the study discovered that a third dosage was nearly 90% effective in reducing COVID-19 hospitalisations during a period of December and January when Omicron was dominant. The CDC study found this while they evaluated nearly 88,000 hospitalisations across 10 states, as per CNN.  

From the starting of April through the end of December, the second research looked at COVID-19 instances and mortality rates in 25 states. People who had their immune systems strengthened had the best protection against coronavirus disease, both while Delta was prevalent and after Omicron took over.  

The second research, which was published in the CDC's Morbidity and Mortality Weekly Report on Friday, found that those who had booster shots were less likely to contract Omicron. The CDC researchers discovered that among individuals who were boosted, there were 149 instances per 100,000 individuals on average each week, based on the statistics from 25 state and local health agencies. It was 255 instances per 100,000 individuals for those who only received two doses. 

The third study, which was also headed by CDC experts, was published in the Journal of the American Medical Association. It monitored individuals who tested positive for COVID-19 between December 10 and January 1.

When compared to unprotected persons, booster shots of the Pfizer and Moderna vaccines were roughly 67% efficient against Omicron-related symptomatic illness. The researchers discovered that two doses provided no meaningful protection against Omicron when assessed many months after the first series was completed, AP reported.

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