Inactivated Covid19 Vaccine By CCMB Researchers
The Centre for Cellular and Molecular Biology (CCMB) researchers are set to develop an inactivated virus vaccine for the deadly Covid-19 virus. Inactivated vaccines are known for their easy production and safety.
More than 42 promising vaccine candidates for the novel coronavirus are currently under development, according to the World Health Organisation (WHO).
An active virus is killed either by heat or by a chemical after being cultured in large numbers. Various parts of the virus are intact, (for instance, the spike protein with which it enters the cells) even though the pathogen is killed or made to lose its reproduction capacity. The antigen that is recognized by the immune system is left unimpaired. Unaware that the pathogen is dud, the immune system is tricked to respond by producing antibodies against specific antigens still left intact when this dead microbe is introduced. This is how the rabies vaccines and inactivated polio vaccines are made.
The pathogen cannot cause even a mild disease nor reproduce as it is dead. Thus, even for old people and those who have co-morbidity, it is safe to administer to people with lesser immunity.
The CCMB Director, Dr. Rakesh Mishrasaid, “We can have a material for a candidate vaccine to be injected if we grow a large amount of virus and we can inactivate it. The human body will start making antibodies against the virus after recognizing its proteins even though the virus will not be active. Thus it acts as an inactivated virus vaccine.”
Culturing the virus outside of the human host is an important technological challenge. The key to this technology is locating the right source of the cell line to culture the virus outside of the human body as the SARS-CoV-2 has evolved to live on human cells, especially in cells with active ACE2 receptors. In order to artificially culture and harvest the deadly virus, the epithelial cell line from African green monkey grown in Petri dish is being used by CCMB.
To find the right one on which the novel coronavirus can infect, grow and multiply, a few more cell lines options will be explored. The culture is positive if the cells show changes, such as dying of cells and the release of the virus.
Dr. Mishra said, “In order to be able to make an in-vitro system, which can be checked for its potential, we are growing the cells in the culture that will harbor the virus.” The vaccine would be developed after the novel coronavirus grown in the cell culture is harvested and then inactivated.
Identifying the right cell culture technology for the Covid-19 virus will also be useful in developing drugs. The potential drug candidate can be tested against the same, once a virus infects the cells.
He explained, “lots of viruses would be produced if we infect fresh cells with the virus, as the cells would be dead after 2-3 days. However, the cell will not die and the replication of viruses would be arrested if the drug is effective, if you administer the potential drug. One can check if a particular drug is effective as antiviral in this way.”
To test a large number of suspects harboring virus infection, CCMB will pool in samples and use its facilities, apart from this.
Inactivated Covid19 Vaccine By CCMB