Pfizer vaccine's single dose provides strong immunity to those who have had Covid-19: Study

A single dose of Pfizer-BioNTech's coronavirus vaccine is enough to provide strong protection to those people who have had the deadly virus, two studies from the UK claim. 

The studies, published late on Thursday in The Lancet, bring strong evidence to conclude that people who have had coronavirus can get robust protection from Pfizer's vaccine, but only one dose. 

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"This could potentially accelerate vaccine rollout," suggest one of the study's authors from the University College London and Public Health England, as reported by The New York Times. 

They further added that by following this strategy, dangerous mutations of the virus can be negated. 

"Wider coverage without compromising vaccine-induced immunity could help reduce variant emergence," the study said. 

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The study led by University College London and Public Health England analysed data of 51 healthcare professionals in London. 

Amongst these participants, 24 people have previously had Covid-19. 

These healthcare workers received a single dose of Pfizer's shot and then were tested for antibodies 19 to 29 days later.

The research noted that those who have previously had coronavirus, vaccination increased their antibody levels more than 140 times.  

"This increase appears to be at least one order of magnitude greater than reported after a conventional prime-boost vaccine strategy in previously uninfected individuals," their paper said. 

The second paper of researchers from Imperial College London and other UK institutions included data of 72 healthcare workers who were inoculated late in December. 

Amongst the participants, 21 have had coronavirus infection in the past. 

These participants blood samples were taken after receiving the first dose and then 21-25 days post-inoculation. 

The study concluded that people with previous Covid-19 infection appeared to generate better immune responses to one dose of Pfizer's drug as compared to those who had not been infected with the virus ever.