COVID-19: Protection offered by two doses of vaccine wanes within six months, says study

As the COVID-19 situation continues to be fragile and the threat still far from over, countries across the world have ramped up the vaccination drive for the safety of their citizens. However, a recent study by researchers in the United Kingdom found that protection against COVID-19 offered by two jabs of the Pfizer-BioNTech and the Oxford/AstraZeneca vaccines start to wane within six months. An analysis of data collected in Britain’s ZOE COVID study showed that after five to six months of vaccination, the effectiveness of the Pfizer jab at preventing COVID-19 infection fell from 88% to 74%, whereas, for the AstraZeneca vaccine, effectiveness fell from 77% to 67%. The researchers stated that the study was based on data from more than 1.2 million test results.  

'Protection could fall even below 50% under the worst-case scenario' 

Speaking to BBC television, Tim Spector, principal investigator for the ZOE COVID study, said that protection could fall even below 50% under the worst-case scenario for older people and healthcare workers by winter, which makes taking the booster shots all the more important. He further stated that people concerned need to tackle the issue as the number of cases and the chance of infection are still high. It should be mentioned here that Britain is mulling to plan for a COVID-19 vaccine booster campaign later this year. This comes after it was analysed that it might be necessary to give third shots to the elderly and most vulnerable from September. 

Earlier, a study by the researchers at the University of Oxford had found that the effectiveness of the Pfizer-BioNTech vaccine against Covid-19 declines faster than that of the AstraZeneca jab. The study revealed that two jabs of Pfizer-BioNTech have higher initial effectiveness against the virus but this declines at a greater rate compared with two doses of Oxford-AstraZeneca. The study's result has come at a time when Israel is already administering booster shots after inoculating at least 58% of its population with two hots of the Pfizer jab. The study based its result upon examining two groups of more than 3,00,000 people over the age of 18 years.

Image Credit: Pixabay/Representative