By TIOL News Service

NEW DELHI, JULY 06, 2020: WITH the announcement of COVAXIN by Bharat Biotech and ZyCov-D Vaccine by Zydus Cadila the proverbial silver line in the dark clouds of COVID19 appears at the horizon. Now the nod given by the Drug Controller General of India CDSCO (The Central Drugs Standard Control Organisation) for the conduct of the human trial for the vaccines, marks the beginning of the end.

In the past years, India has emerged as one of the significant vaccine manufacturing hubs. Indian manufacturers account for 60% of vaccine supplies made to UNICEF. The vaccine for novel coronavirus may be developed anywhere in the world, but without Indian manufacturers involved the production of required quantity is not going to be feasible.

Vaccine race

More than 140 candidate vaccines are under various stages of development. One of the leading candidates is AZD1222 developed Jenner Institute of University of Oxford and licenced to AstraZeneca British-Swedish multinational pharmaceutical and biopharmaceutical company headquartered in Cambridge, England. The MRNA-1273 vaccine developed by Kaiser Permanente Washington Health Research Institute, Washington and taken up for production by the US-based Moderna pharmaceutical is just a step behind. Both these firms have already inked an agreement with Indian manufacturers for production of the COVID vaccines.

Parallelly Indian institutions have also engaged in R&D for the development of vaccines in India. With the primary scientific inputs coming from institutions like Pune based ICMR institution National Institute of Virology and Hyderabad based CSIR institution Center for Cellular and Molecular Biology, six Indian companies are working on a vaccine for COVID-19. Along with the two Indian vaccines, COVAXIN and ZyCov-D, the world over, 11 out of 140 vaccine candidates have entered the human trials.

Immune system

Antigen from the pathogen and antibodies produced by the human immune cells can be thought of as matching the compatible pair. Every pathogen has specific molecular structures called as antigen. They are like the surface with a particular hue and design. Once infected by the germ, the human immune system develops antibodies that match the antigen.

Just as the retailer of design matching material stockpile hundreds of design pieces of riots of colours and hues, our immune system has ten thousand types of antibodies. If the pathogen is a known enemy, the immune system can pull the matching design piece from the stock. Once the match is made the pathogen is inactivated. No longer it can infect.

However, if the microorganism is unfamiliar, and mainly when it has evolved for the first time, there is no matching colour and hue in the repertoire.  Nonetheless, unlike the textile, the antibody can evolve. At first, near matches are tried. After various cycles of antibody development, the best fit matures. The time lag between the identification of the main surface colour that is an antigen, and finding a pairing design piece, that is antibodies, is what makes the infection mild or severe. If only the immune system can neutralise the germ instantly, the infection can be prevented.