New Delhi: SinoVac Biotech’s CoronaVac can effectively prevent Covid-19, including severe disease and death, a study by researchers in Chile has found.
According to the researchers, including from the Chilean Ministry of Health and some institutes in the country, CoronaVac was found to prevent laboratory-confirmed Covid-19 in 65.9 per cent of the people who were fully vaccinated (two-dose regimen), prevent hospitalisation in 87.5 per cent, prevent ICU admission in 90.3 per cent, and death in 86.3 per cent.
The study was published Thursday in the peer-reviewed The New England Journal of Medicine.
Developed by Chinese company Sinovac Biotech, CoronaVac is based on an inactivated virus. The majority of vaccinations in Chile have been carried out with CoronaVac.
Sinovac has been approved by 39 countries, and validated by the WHO for emergency use.
“Our results suggest that the inactivated SARS-CoV-2 vaccine effectively prevented Covid-19, including severe disease and death, a finding that is consistent with results of phase 2 trials of the vaccine,” the researchers say.
The study altogether involved approximately 10.2 million (1.02 crore people), and was conducted from 2 February through 1 May 2021.
The participant cohort, aged 16 years or above, was affiliated with the national public health insurance programme, Fondo Nacional de Salud, which includes 80 per cent of the Chilean population.
“We classified participants into three groups: Those who were not vaccinated, those who were partially immunised (≥14 days after receipt of the first vaccine dose and before receipt of the second dose), and those who were fully immunised (≥14 days after receipt of the second dose),” the researchers said.
Of the 1,01,87,720 participants, 41 per cent or 41,73,574 had received both doses of the vaccine, 5.3 per cent or 5,42,418 had received one dose, and 53.7 per cent or 54,71,728 were unvaccinated.
The researchers focused on various outcomes, including laboratory-confirmed Covid-19, hospitalisation, admission to the ICU for Covid-19, and death from the disease.
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What the researchers found
The researchers found that the incidence rate — number of new cases occurring within a time period — of a person contracting the infection was lowest in the fully immunised group (0.1340 vs 0.2990 in partially immunised and 0.3019 in unvaccinated).
The incidence rate of hospitalisation was 0.0158 among the fully immunised group, 0.0477 among the partially immunised, and 0.0290 among the unvaccinated.
Meanwhile, very few people — 360 — in the fully immunised group had been admitted to the ICU. This figure was 1,154 for the partially immunised group, and 18,034 in the unvaccinated group.
The incidence rate of deaths in the cohort was 0.0044 among those who were fully immunised, 0.0120 in those who had received one dose, and 0.0045 in the unvaccinated group.
(Edited by Sunanda Ranjan)
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