By Sumit Saxena

New Delhi, Feb 25 (IANS): India is fighting one of the toughest battles against the Covid-19 outbreaks. The battle turned intense after daily cases resurged following a few weeks drop from a peak of over 90,000 infections in mid-September to a little over 10,000 in early February.

It has begun to rise again in many states along with thousands SARS-CoV-2 mutations. The genetic diagnostic laboratories in India have detected over 24,000 mutations in the strains of SARS-CoV-2 in the last one year, top officials told IANS this week.

Although scientists believe these mutations do not translate into variants, but there exists an uphill task to vaccinate the country, as the virus continues to mutate.

Speaking to IANS, Mrinalini Darswal, a doctor turned IAS officer who is pursuing doctoral studies in public health with a focus on Covid-19 at Harvard University, said: "We are in a position to launch modified vaccines within weeks due to the technical know-how we have gained over the last year."

Excerpts of the interview:

Q: COVID-19 has already started mutating, and it will continue to mutate as the vaccination drive progresses. Cases infected with three main reported variants from the UK, South Africa and Brazil have been found in India. Do you think Indian vaccine platform can address these mutations and continue to provide vaccines effective against the virus?

A: The resurgence in cases of Covid-19 seen in various states in India could be due to waning of earlier immunity or reinfection with new and more contagious strains. Emergence of mutations in Coronavirus is a concern across the globe. India has also reported new and unique mutations in addition to the UK and South Africa ones.

We would know what mutations need modified measures, if they need these at all, as soon as ICMR and other research institutions come out with findings on the variants among the infected.

Fortunately, most existing vaccines seem to work against the new variants, albeit with variable potency. All prevent severe disease as per extant research. As more data comes in, we would either tweak existing vaccines or start using the new and more effective ones. Again, we are in a position to launch modified vaccines within weeks due to the technical know-how we have gained over the last year.

We also have more than 20 more candidate vaccines in various development stages, and many of these are likely to be effective against the new variants. Existing manufacturers are also working on improving existing formulas and designing boosters for the new strains. WHO also recommends going ahead with current vaccination regimens.

Q: These mutated variants spread faster. In the future, they are most likely to replace existing variants. The UK variant is deadlier for older age groups, and the South Africa variant is evasive but not lethal. In this backdrop, what is the learning for the vaccine development program in India?

A: India has emerged as a global leader in vaccine development against Covid-19. We were able to roll out our indigenous vaccines very early. Those have proved to be very safe and effective and logistically superior to those of Moderna and Pfizer. UN and WHO chiefs have thanked and appreciated India heartily for its rapid pace of vaccine development and supplying the vaccines to other countries, directly and through WHO's vaccine alliance.

This year's budget also has made provisions for new institutes for research in infectious diseases and viruses. At the global level, WHO has enhanced its genomic surveillance and information sharing on new variants. It advises countries and manufacturers to be prepared to adjust to the SARS-CoV-2 viral evolution, including potentially providing future booster shots and adapted vaccines if found to be scientifically necessary. Indian National Task Force on Covid-19 is already on the job.

A genomic surveillance consortium, INSACOG, has been formed under NCDC's (National Centre for Disease Control) leadership, New Delhi, for laboratory and epidemiological surveillance of circulating strains of SARS-CoV-2 in the Country.

Hopefully, we will be able to stay ahead of the virus by rapidly modifying existing vaccines and getting new vaccines wider in coverage of variants to stop the pandemic finally. We have been successful with influenza (flu), a similar virus that mutates every year. Being a pharma leader, India has the technical edge of developing new and improved vaccines in the required time.

Q: New strains will continue to emerge. When do you see the Indian population developing herd immunity, would it be by 2021 end?

A: Sero surveillance shows pockets of the population in Indian cities have antibodies against the novel Coronavirus. But that is at a level not sufficient for developing herd immunity. Unfortunately, there is a resurgence of infections in many states indicating new variants might be replacing the older, making earlier immunity less protective. If that is the case, we might never be able to rely on herd immunity for Covid-19, with it developing into a case similar to the common cold and annual flu. Also, vaccinating the entire population on the planet to achieve herd immunity would take many years- seven, at least if the current vaccination rate is maintained. That, too, if the virus remains unchanged for all these years. Therefore, the better strategy is to cover vulnerable groups and to keep infection rates low and manageable. Other measures like wearing masks, hygiene, and social distance will stay extremely relevant besides vaccines to achieve that aim.

Q: When do you think we will have data to determine the need and timing of booster shots for future vaccination programs?

A: As we continuously monitor and research how long the immunity will sustain for different vaccines, we might know the answer as time progresses. Moderna research says the response lasts for four months; others say longer. Since the immune response to the virus is mediated by antibodies that we measure (B cell immunity) and other fighter chemicals like cytokines and interferon (T cell immunity), we need to see what type of response lingers. Any combination may persist and provide immunity for longer or shorter periods. We will know only after more studies and more time. Whatever may be the case, we are ready to adapt our response quickly to emerging needs and new variants.

Q: In future, will booster shots sufficient to address SARS-CoV-2 viral evolution, or is there something else that the vaccine developed should focus on?

A: We do not have answers to these questions as yet. Research is continuing in parallel as the first line of vaccines is administered. One can only assess the longevity of immunity in inoculated individuals, the protection against variants, and the need for booster shots as data becomes available from people who are getting vaccinated.

Q: Do you think, after Covaxin phase 3 trial results are out, it will help in determining the need for booster dose in future?

A: It would be too early for any vaccine currently available to know the long-term effect and persistence of immunity. We must monitor the immune response in vaccinated people for a longer time to answer this question.