Virendra Pandit
New Delhi: Amid a new Indian Council of Medical Research (ICMR) study’s findings that most Covid-19 positive patients, who got at least one vaccine shot before catching the virus, were infected by the Delta variant, a heat-tolerant vaccine formulation developed by the Indian Institute of Science (IISc) has proven effective against all Variants of Concern (VOCs).
The ICMR study is the first such analysis on breakthrough infections post-vaccination. It showed that most of the post-vaccination patients were infected by the Delta variant in India, which was found for the first time in October 2020.
Meanwhile, a heat-tolerant Covid-19 vaccine formulation developed by the IISc, Bengaluru, has been found effective against all current SARS-CoV-2 VOCs, according to a study conducted on animals.
The research, published in the ACS Infectious Diseases journal on Thursday, showed that vaccine formulations by the IISc-incubated biotech start-up Mynvax triggered a strong immune response in mice.
The researchers, including those from Australia’s Commonwealth Scientific and Industrial Research Organisation (CSIRO), found that most vaccines require refrigeration to remain effective. But the IISc’s formulation remained stable at 37 degrees Celsius for up to a month, and at 100 degrees Celsius for up to 90 minutes.
In contrast, the Oxford-AstraZeneca vaccine, called Covishield in India, must be stored at a temperature of between 2 and 8 degrees Celsius and the Pfizer preventive requires specialized sub-zero cold storage at minus 70 degrees Celsius.
S S Vasan, CSIRO’s Covid-19 project leader and co-author of the study, said the Mynvax-vaccinated mice sera show a strong response to all variants of the live virus.
“Our data show that all formulations of Mynvax tested result in antibodies capable of consistent and effective neutralization of the Alpha, Beta, Gamma and Delta SARS-CoV-2 VOCs,” Vasan said.
CSIRO’s evaluation of the different Mynvax formulations will support the selection of the most suitable candidate for planned human clinical trials in India later this year.
Earlier, the IISc had conducted a preclinical evaluation of two Covid-19 vaccines including the Oxford-AstraZeneca preventive, said CSIRO’s Health and Biosecurity Director, Rob Grenfell.
“A thermo-stable or ‘warm vaccine’ is critical for remote or resource-limited locations with extremely hot climates which lack reliable cold storage supply chains, including regional communities in Australia’s outback and the Indo-Pacific region,” Grenfell said.
In addition to the IISc and CSIRO, the study included researchers from the University of York in the UK, CSIR-Institute of Genomics and Integrative Biology (CSIR-IGIB), New Delhi, Translational Health Science, and Technology Institute, Faridabad, and CSIR-Institute of Microbial Technology, Chandigarh.
