Immunity acquired from natural COVID-19 infection or vaccines is not absolute according to emerging evidence, Minister of State for Health Bharati Pravin Pawar told the Lok Sabha on Friday.
Reinfections following natural coronavirus infections as well as vaccine breakthrough infections are not uncommon, the minister added in a written reply.
Breakthrough infections were observed in 7.91 per cent of the sample population in a study involving 1,112 vaccinated people who had at least one dose of either Covaxin or Covishield, she said. The study was published in the Journal of Medical Virology in March 2022.
Out of 88 post-vaccination SARS-CoV-2 breakthrough infections, 90.91 per cent were symptomatic cases and the remaining 9.09 per cent were asymptomatic. Among symptomatic breakthrough infections, 31.25 per cent were mild, 43.75 per cent moderate and 25 per cent severe, Pawar said.
According to the World Health Organization, a vast majority of infections are observed in unvaccinated populations, and if breakthrough infections occur in vaccinated persons, they are in most cases less severe than those seen in unvaccinated persons.
(With PTI inputs)