The findings have cast a doubt on India’s decision to extend the interval of Covishield, the vaccine developed by Oxford University-AstraZeneca and manufactured by the Serum Institute of India, to 12-16 weeks given the variant’s ability to infect people who are partly vaccinated.
“Now that the Delta variant makes up a very large fraction of infections in India, I hope the government’s empowered committee on vaccinations will consider reducing the duration between two doses of Covishield,” Jameel opined.
Immunologist Dr. Vineeta Bal also believes that going by PHE’s study, the earlier people get the second dose, the better protection it will offer against the variant.
“If we have enough doses of COVID-19 vaccines, it would have been desirable to stick to 6-8 week interval for Covishield vaccine due to the higher transmissibility,” she told Moneycontrol.
Meanwhile, Hyderabad-based Bharat Biotech, the maker of Covaxin, has also stated that the vaccine works against the variant.
A study by researchers from the National Institute of Virology in Pune, the Indian Council of Medical Research and Bharat Biotech has found that Covaxin is effective against the Beta and Delta variants of COVID-19.
The study, which is pre-print and has not yet been peer-reviewed, is based on samples from 20 people who recovered from COVID-19 and 17 people who received their second dose of Covaxin at least 28 days prior to the study.
While the results are encouraging, experts believe the ‘conflict of interest’ needs to be addressed.
“Science works on independent verification by those who have no conflict of interest. All authors of this particular study have either a reputational (NIV, ICMR) or financial (Bharat Biotech) conflict of interest. By saying that none of the authors have a competing interest, the authors are misrepresenting facts. They should correct this,” Jameel said.
Moreover, a contradictory study by the All India Institute of Medical Sciences suggested that the variant has the potential to infect people who have received Covishield or Covaxin shot. AIIMS, New Delhi had conducted a small study on 63 people.
Out of these 63 people, 35 received both dose of vaccines and 27 received only one dose. All of them got breakthrough infections (infections after vaccination) and among the samples which were genome sequenced, the Delta variant was predominant.