Scientists relay importance of 2nd COVID vaccine dose to safeguard against new variants

A recent study published in the journal 'Scientific Reports' stressed the importance of inoculating the second dose of the COVID vaccine. The study, led by a team of scientists, including biological anthropologist Thomas McDade and pharmacologist Alexis Demonbreun, stressed the second dose of vaccine safeguard a person from contracting the emerging variants, including the highly contagious delta variant. The study also showed that prior exposure to SARS-CoV-2 does not guarantee a high level of antibodies, nor does it guarantee a robust antibody response to the first vaccine dose.

Researchers advocate inoculating with both doses of vaccine

However, it is worth noting that the recent research published in the journal Scientific Reports contradicts the assumption that contracting COVID will naturally make someone immune to re-infection. The researcher advocated for inoculating both doses of the vaccine irrespective of contracting the deadly virus in recent days. Explaining the method of the research, McDade, professor of anthropology in the Weinberg College of Arts and Sciences and a faculty fellow with the University's Institute for Policy Research said they had collected the blood samples from adults who had tested positive for coronavirus. The samples were taken in order to measure how long the immunity benefits of Pfizer and Moderna vaccines last. The samples were also taken to figure out the protection from the latest covid variant. 

'Prior exposure to SARS-CoV-2 does not guarantee a high level of antibodies'

According to the scientists, the antibody responses declined by about 20% two months after the second dose was administered. 
"When we tested blood samples from participants collected about three weeks after their second vaccine dose, the average level of inhibition was 98 per cent, indicating a very high level of neutralising antibodies," said researcher McDade in the journal published on August 30. "Many people, and many doctors, are assuming that any prior exposure to SARS-CoV-2 will confer immunity to re-infection. Based on this logic, some people with prior exposure don't think they need to get vaccinated. Or if they do get vaccinated, they think that they only need the first dose of the two-dose Pfizer/Moderna vaccines," McDade added.

"Our study shows that prior exposure to SARS-CoV-2 does not guarantee a high level of antibodies, nor does it guarantee a robust antibody response to the first vaccine dose. For people who had mild or asymptomatic infections, their antibody response to vaccination is essentially the same as it is for people who have not been previously exposed," McDade explained.

As far as protection goes after vaccination, the story is the same for all the variants, including delta -- the vaccine provides good protection, but not as good protection as the original version of the virus for which the vaccine was designed, noted the scientist. The researcher appealed to the government to increase the production of the covid vaccine on an "urgent basis".  Also, he appealed to the developed nations to share the vaccine doses with the developing countries. "Everyone, everywhere should have the right to receive the full course. Vaccination is a right, but it is also a responsibility," said McDade.

(With inputs from ANI)

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