Will baker’s yeast yield a vaccine against COVID-19 ? Premas Biotech, a Gurugram-based biotechnology company is set to find out and has signed a licensing deal with Aker Biosciences, a United States-based biotechnology company, to develop a vaccine.
Interactive map of confirmed coronavirus cases in India
Given the present pandemic, several companies around the world are hastening to fast track vaccine development and drug development to counter the novel coronavirus that has so far infected at least 4,00,000 persons around the world. To accelerate development, drug regulators around the world — including in India — have announced plans to fast track regulatory process for COVID-19 related vaccine and drug development efforts.
By April
By April, Premas hopes to be ready with a 'proof-of-concept' recombinant vaccine candidate made out of proprietary manufacturing process that involves the use of the yeast species, S cerevisae, a well understood system and used to make vaccines. If the results are promising, the company hopes to present to the United States FDA and simultaneously the Drug Controller General of India and await instructions on the kind of trials they would have to undertake.
In commonly used vaccines, ‘live attenuated’ — a weakened strain — of a live virus, is injected into people to have their immune systems recognise and produce antibodies. In recent decades, biotechnology has moved on to trying to eliminate viruses altogether in vaccines as they may be ineffective, elicit unpleasant side-effects or be unusable in certain groups of patients.
Recombinant vaccines consist of synthetic proteins that mimic the ones that make up the virus’ exterior. Genes that make these proteins are put in bacterial or fungal factories — in this case yeast — and the resulting purified protein is used in the vaccine. The challenges lie in identifying the right proteins, making enough of it quickly and ensuring that the resulting mix of proteins is good quality and enough to stimulate the immune system to produce antibodies.
In the context of Sars-Cov-2, which is responsible for the ongoing pandemic, researchers have so far focussed maximum attention on the ‘spike proteins’.
Coronaviruses are all typified by a spiky outer facade. However subtle changes to the Sars-Cov-2 spikes have made them better able to infiltrate the cells of the airways — and more dangerously the lung cells where they commandeer resources needed by normal cells to survive. The most serious Sars-Cov-2 infection results when a pulmonary infection is caused by this invasion.
Wider spectrum
While some firms — including the Pune-based Serum Institute of India and U.S.-based Codagenix — have announced plans to try a live attenuated vaccine, Premas and Aker hope to be able to make a vaccine that doesn't just look at the ‘spike proteins’. The others, of interest to Premas, are envelope and membrane proteins all of which make up layers of the virus.
Using more of these proteins — or antigens — to make the vaccine improves the odds of the immune system detecting them and producing antibodies and protecting the body from a future viral attack. While several research groups work and biotechnology firms race to solve this problems, Premas says it has already synthesised two of the three proteins — thanks to its platform technology called D-Crypt.
“Through the years we have made over 30 difficult-to-express proteins. We are able to make large quantities of them and can be scaled up to industrial levels for trials. That is where we think we have an edge,” Prabuddha Kundu, Co-founder and Managing Director, Premas, told The Hindu . Experts have said it will be at least a year-and-a-half before a potential vaccine for COVID-19 can make it to the market.
