Pfizer, Moderna vaccines likely to provide protection against COVID-19 for years, says study

A recent study published in the journal 'Nature' has stated that those administered the Moderna or Pfizer-BioNTech COVID-19 vaccines may remain protected against coronavirus infection for years. Scientists, who worked on the study,  had stated on Monday that these COVID-19 vaccines generate a persistent immune response that may be capable of protecting beneficiaries for years.

The scientists have found evidence that suggests that those people given the mRNA vaccines (Pfizer and Moderna jabs are both mRNA vaccines) may not need booster shots if the coronavirus variants do not evolve much beyond their current forms. The findings of the study have further noted that those who have recovered from COVID-19 infection before getting vaccinated may not need booster shots even if the virus evolves or transforms.

The study published in Nature was led by Dr Ali Ellebedy, an immunologist at Washington University in St. Louis.  "It's a good sign for how durable our immunity is from this vaccine," The New York Times quoted him as saying.

The scientists as part of this study did not examine the Johnson & Johnson COVID-19 vaccine.

How was the study conducted?

The group of scientists led by Dr Ellebedy studied 41 people have had been given two doses of the Pfizer vaccine. Eights of these individuals had been infected with COVID-19 before immunisation. The researchers took samples from the lymph nodes of 14 individuals, after the third, fourth, fifth, seventh, and 15th week of their first dose.

Study Findings

The scientists discovered that in the 14 individuals, the germinal centre was still highly active,15 weeks after vaccination.

This meant that the number of memory cells that could detect the coronavirus had not reduced in number. "The fact that the reactions continued for almost four months after vaccination - that's a very, very good sign," noted Ellebedy, according to the daily. Germinal centres usually peak in the first two weeks after vaccine administration.

"Usually by four to six weeks, there's not much left. But germinal centres stimulated by the mRNA vaccines are still going, months into it, and not a lot of decline in most people," Deepta Bhattacharya, an immunologist at the University of Arizona, as per The New York Times' report.

"Everyone always focuses on the virus evolving - this is showing that the B cells are doing the same thing. And it's going to be protective against ongoing evolution of the virus, which is really encouraging," said Marion Pepper, an immunologist at the University of Washington in Seattle.

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