Single jab enough for Covid-19 survivors: Study

Researchers have found that COVID-19 survivors might only need one dose of the vaccine. Two different studies published on medRxiv proposed a potential way to save vaccines for millions by administering one dose to people who recovered from the pandemic.

Researchers from Icahn School of Medicine at Mount Sinai in New York in their studies examined antibody responses to a single dose of the Pfizer-BioNTech or Moderna vaccines on previously Covid-19 infected healthcare workers (HCW). The respondents exhibited a higher antibody response with just one dose as their immune systems are familiar with the virus. They also reported unpleasant side effects such as headache, fever, and muscle or joint pain more frequently after the first dose vaccine than other respondents who did not contract the virus.

The COVID-19 vaccines that have been currently authorized in most countries require two doses. However, several other studies show that the number of doses in any vaccination series for conditions such as Hepatitis A or B, polio, influenzas, and meningitis can differ based on risk group, age and other factors. The second dose of any vaccine, also called booster shot, is usually administered because all body types may not respond satisfactorily to a single jab.

"Changing the policy to give these individuals only one dose of vaccine would not negatively impact on their antibody titers, spare them from unnecessary pain and free up many urgently needed vaccine doses," the authors of the paper said.

But University of Edinburgh specialist Professor Eleanor Riley said that 'implementing this as part of a comprehensive vaccination programme can be logistically complex and it may be safer to ensure that everyone gets two doses,' as quoted by International Business Times.

While Pfizer-BioNTech has reported its need for booster jabs, Moderna is still assessing if the second dose can bid extra protection than the first jab against COVID-19 variants. Another vaccine developed by Johnson & Johnson vaccine, if licensed, would require only a single administration.