Hyderabad-based pharmaceutical company Bharat Biotech recently shared the findings of an animal study conducted to test its indigenous COVID-19 vaccine candidate Covaxin.
The experimental vaccine was administered on monkeys, and induced a strong immune response in them, protecting them from the viral infection. According to an Indian Express report, a reduction in the replication of the virus in the nasal cavity, throat and lung tissues of the monkeys was observed.
Bharat Biotech said in a recent tweet that the results of this trial demonstrated the protective efficacy in a live viral challenge model.
The findings of the study were posted on Research Square, an academic pre-print server. They are yet to be peer reviewed.
For the study, scientists from ICMR-National Institute of Virology and other institutions evaluated the protective efficacy and immunogenicity of the inactivated SARS-CoV-2 vaccine (BBV152) in rhesus macaques (Macaca mulata).
Twenty monkeys were divided into four groups of five animals each. Participant macaques in one of the groups received a placebo, while those in the other groups received three different versions of the inactivated vaccine - slightly varying in their composition or dose.
All monkeys received either two doses of the placebo injection or of the experimental vaccine.
Two weeks after the second dose was administered, the monkeys were exposed to the SARS-CoV-2 virus. The researchers transferred large amounts of the virus into the animals’ windpipes and both their nostrils.
A week after the exposure, SARS-CoV-2 RNA could be detected in the monkeys belonging to the placebo group, but no viral genetic material was observed in the vaccinated monkeys.
Viral genetic material was also absent in fluid samples procured from the lungs of the vaccinated monkeys, indicating that the vaccine candidate had obstructed virus replication and enabled its expulsion from the lower respiratory tract. For the placebo group, the lung examinations revealed moderate to severe disease in three, and mild disease in two monkeys.
Covaxin has been jointly developed by Bharat Biotech, ICMR-National Institute of Virology.
(With inputs from The Indian Express)
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