India's ‘warm’ vaccine shows results against all variants of concern

BENGALURU: The ‘

warm

’

vaccine

formulations developed by scientists at IISc and biotech firm Mynvax result in antibodies that neutralise all current SARS-CoV-2 variants of concern, an independent evaluation of the formulations done by

CSIRO

,

Australia

, — the agency that had done animal tests for the Oxford-Covishield vaccine candidate last year — has shown.


The findings have been published (on Thursday) in the peer-reviewed

ACS Infectious Diseases

journal and will pave the way for clinical development leading to human trials. The published study was led by

Prof Raghavan Varadarajan

from IISc and TOI first reported about the vaccine in November 2020.

As per the paper, researchers have shown the formulations triggered a strong immune response in mice, protected hamsters from the virus, and remained stable at 37°C up to a month and at 100°C for up to 90 minutes — living up to its “warm vaccine” tag.

Most vaccines require refrigeration to remain effective — Oxford-AstraZeneca must be kept between 2-8°C; Pfizer requires specialised cold storage at -70°C.

The IISc-Mynvax vaccine has been designed by genetically engineering a domain of the S-Protein of the SARS-CoV-2 virus, called the Receptor Binding Domain (RBD), which attaches itself to the Ace2 receptor on the surface of target cells in the human respiratory tract. This enables the virus to enter the body and cause the infection.

S-Protein of the virus is about 1,300 amino-acids long but the vaccine focuses only on a string of 200 amino acids.

Variants of concern & human trials
Explaining about the next course of action, Varadarajan said they had applied to the Government for grants/funds for the Phase-I/II and Phase III human trials in India.

“We would require at least Rs 30 crore for the trials and at this moment, all I can say is that funding has been applied for,” Varadarajan told TOI, adding that the formulations had resulted in antibodies that neutralise SARS-CoV2 variants of concerns as shown by the pseudo-viral assays done at the CSIR-IMTech in India, and also that the results from the live virus tests by CSIRO were very encouraging.



CSIRO played a key role in evaluating the formulations against all current SARS-CoV-2 variants of concern. “CSIRO scientists at the Australian Centre for Disease Preparedness in Geelong contributed to the study by assessing vaccinated mice sera (blood samples) for efficacy against key coronavirus variants, including the Delta variant currently spreading globally including in Sydney,” CSIRO said in a statement shared with TOI.



Prof SS Vasan, CSIRO’s Covid-19 project leader and co-author, said the vaccinated mice showed a strong response to all variants of the live virus. “Our data shows that all formulations tested result in antibodies capable of consistent and effective neutralisation of the Alpha, Beta, Gamma and Delta SARS-CoV-2 variants of concern,” he said.

Vasan told TOI in an exclusive telephonic interview: “CSIRO will continue to work with the IISc to develop therapeutic applications that will complement vaccination strategies. The lack of safe, effective and affordable therapies that specifically targets this virus is an urgent and unmet need.”