A prospective vaccine against SarsCov2 being developed in India, that doesn’t need to be stored in refrigerators or cold-chain storage, generated a significant number of antibodies in mouse trials against prevalent variants of the virus, according to a study in the peer-reviewed journal Viruses.
The ‘warm’ vaccine developed by the Bengaluru-based Mynvax laboratories, a company incubated at the Indian Institute of Science Bangalore, is unique among existing vaccines in that it can be stored at 37 degree Celsius for four weeks and at 100 degree Celsius for upto 90 minutes.
Most other vaccines require to be stored in refrigerators and can be kept at room temperature for no more than a few hours.
However the test of a vaccine is whether it can elicit a sufficiently high antibody response out of the immune system and whether the vaccine was effective against variants: Alpha, Delta and Omicron.
Existing vaccines have been developed on the template of the Wuhan strain whereas the prevailing variants have significant structural differences that improve their chances of evading the immune system-generated antibodies.
Joint studies by scientists at Mynvax and Australia’s Commonwealth Scientific and Industrial Organisation (CSIRO) reported a 14.4-fold reduction in neutralisation against BA.1.1 for the three monomeric antigen-adjuvant combinations and a 16.5-fold reduction for the three trimeric antigen-adjuvant combinations compared to the antibodies generated against the wild type of the virus.
When tested against the Delta variants, the reduction was 3-5 times.
Monomeric and trimeric refer to different shapes that can be used to construct the vaccines.
The COVID-19 vaccine candidate contains a part of the spike protein of the novel coronavirus called the receptor binding domain (RBD) ‒ the region that helps the virus stick to the host’s cell and is being developed by Raghavan Varadarajan, Professor at the Molecular Biophysics Unit, Indian Institute of Science (IISc) in collaboration with Mynvax, a startup co-founded by him and incubated at IISc, as well as several other institutes. The company was founded in 2017 to develop flu vaccines.
“The 14.4- or 16.5-fold reduction in neutralisation against Omicron BA.1.1 for the monomeric and trimeric formulations, respectively, compares favourably with equivalent reductions observed with leading COVID-19 vaccines,” the authors note in their study.
The results, they add, attest to the vaccine being fit to proceed to trials in people. Two years into the pandemic, close to 10 billion doses of COVID-19 vaccines have been administered to date, indicating that 4.4 billion of the world’s population has been fully vaccinated. However, nearly half the world’s population, predominantly in low-income countries (LICs) and lower middle-income countries (LMICs), is still receiving its first dose of COVID-19 vaccines. These countries are also poorly equipped with cold storage facilities and it’s here, the Mynvax vaccine, could be efficiently deployed, they add.