Ahmedabad-based Cadila Healthcare (Zydus Cadila), which has developed the first approved DNA vaccine in the world for Covid-19, is testing a multi-variant Covid-19 vaccine on animals, a senior company official said.
“We have completed our development for almost eight strains of the Sars-Cov-2 virus. We are now doing animal studies to see which of these constructs work the best to neutralise more mutations of Sars-CoV-2. It can be a vaccine construct using one strain or may be two strains,” said Sharvil Patel, MD, Zydus Cadila.
Patel said the vaccine was in the product development stage and animal studies would show which combination was most effective. Tweaking the DNA-plasmid platform is relatively easy, and takes less time. All one needs to do is to change the sequence of the strains, and the whole construct of the vaccine, the whole model, and the process remain the same. “It is like plug-and-play technology, where all you have to do is to change the strain. We need not change anything that is part of the vaccine platform,” Patel said.
As such, Zydus Cadila’s ZyCoV-D, the DNA vaccine, when administered, induces production of spike protein of the Sars-CoV-2 virus. It is also stable across a wide temperature range. It is stable at 2 to 8 degrees and also at 25 degrees Celsius for around three months, unlike the stringent temperature requirement of mRNA vaccines.
Zydus has developed India’s first tetravalent influenza vaccine Vaxiflu-4, which offers protection against four influenza viruses — H1N1, H3N2, Type B (Brisbane), Type B (Phuket).
Mixing multiple strains to get what is called a multi-variant vaccine may be a way to get better immunity, scientists feel. Experts like Gagandeep Kang, microbiologist and professor at Christian Medical College, Vellore, pointed out that the scientific community feels that one needs to prepare for the future waves of the pandemic.