Washington, Jul 7: People who receive COVID-19 vaccines by Pfizer and Moderna are up to 91 per cent less likely to develop the disease, according to a US study which also suggests that the preventives reduce the severity of symptoms and duration in those who still get an infection.
The research, published in the New England Journal of Medicine on June 30, is among the first to show the benefits of mRNA vaccines even among those who experience breakthrough infections -- testing positive after immunisation.
The mRNA vaccines by Pfizer and Moderna contain genetic instructions for our cells to make the spike protein of the SARS-CoV-2, which the virus uses to infect and enter the human cells. COVID-19 Vaccine of Pfizer-BioNTech Approved for Use in Children Aged 12 to 15 in UK.
Our immune system then builds an immune response against the spike protein, and learns how to fight off the coronavirus if we encounter it in future.
"One of the unique things about this study is that it measured the secondary benefits of the vaccines," said study co-author Sarang Yoon, an assistant professor at the University of Utah, US.
The study was designed to measure the risks and rates of infection among those on the front lines of the pandemic -- doctors, nurses, and first responders.
"These are the people who are getting exposure to the virus day in and day out, and the vaccine protected them against getting the disease. Those who unfortunately got COVID-19 despite being vaccinated were still better off than those who didn't," he added.
The study found that mRNA COVID-19 vaccines were 91 per cent effective in reducing risk for infection once participants were "fully" vaccinated, two weeks after the second dose.
The researchers also found that the vaccines are 81 per cent effective in reducing risk for infection after "partial" immunisation, two weeks after the first dose was given.
The study recruited 3,975 participants at eight sites in the US. Participants submitted samples for COVID-19 testing on a weekly basis for 17 /wp-content/uploads/2024/11/1-2-6-380x214.jpg#in-large#380#214" alt="Palak Tiwari's Wardrobe is Full of Mini Dresses; 7 Stunning Outfits to Steal (View Pics)" title="Palak Tiwari's Wardrobe is Full of Mini Dresses; 7 Stunning Outfits to Steal (View Pics)" /> Palak Tiwari's Wardrobe is Full of Mini Dresses; 7 Stunning Outfits to Steal (View Pics)