Single dose sufficient for those already infected by Covid: Study

Asingle dose of vaccine is sufficient for those already infected by Covid-19,revealed a study by Hyderabad's AIG Hospitals.

Thehospital announced on Monday that it conducted a study on 260 healthcareworkers who got vaccinated between January 16 and February 5 to assess theimmunological memory response in all those patients. All patients were giventhe Covishield vaccine.

Twosignificant observations came out of the study, which has been published in theInternational Journal of Infectious Diseases, a peer-reviewed journal.

Thepreviously infected group (people who got infected with Covid-19) showed agreater antibody response to a single dose of vaccine compared with those whohad no prior infection.

Italso revealed that Memory T-cell responses elicited by a single dose of vaccinewere significantly higher in the previously infected group compared with thosewho had no prior infection.

Itwas concluded that higher memory T and B-cell responses in addition to higherantibody response with a single dose of vaccine given at 3-6 months afterrecovery from Covid-19 may be considered at par with two doses of vaccine forindividuals already infected with Covid-19.

"Theresults show that people who got infected with COVID-19 need not take two dosesof vaccine yet with a single dose can develop robust antibody and memory cellresponse at par with two-doses for those who didn't get the infection. Thiswill significantly help at a time when there's a shortage of vaccine in thecountry and more people can be covered using the saved doses," said Dr. DNageshwar Reddy, Chairman, AIG Hospitals, and one of the co-authors in thestudy.

"Oncewe attain the requisite number of people vaccinated for achieving herdimmunity, these patients who got infected and received only one dose can takethe second dose of the vaccine. At this point, all our strategies should bedirected at the widespread distribution of available vaccines and to includethe maximum number of people at least with a single dose," he added.

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Duringthe second Covid wave when cases were growing exponentially; the vaccinationrate took a downturn. As of April 27, when the growth rate of active infectionwas 5%, the growth of vaccinated people was just 1.4 per cent.

"Weneed to modify vaccination strategy based on scientific evidence and with theobjective that a larger set of the population can be covered in the shortestduration," he said.