India needs real time mapping of genomic surveillance to enable robust public health response

Bengaluru, June 15, 2021

India needs real time mapping of genomic surveillance that will enable a robust public health response. The chances of emergence of new variants of Covid-19 are a cause of concern due to widespread infections and taking into consideration our population.

Only if the country keeps a high level of genomic vigilante, it will be able to pick up new mutants quickly and effectively mount a public health response with test, treat, trace and isolation.

This is a genuine cause of worry. While we were aware the second wave had to do it new variants. This comes as tangible proof that majority affected are harboring new variants, Dr Vishal Rao, Dean – Centre of Academic Research, HCG Cancer Hospital told Pharmabiz.

Mapping the vaccine efficiency is essential as this virus is rapidly mutating and creating new resistant variants. The vaccine currently available has been made using original Wuhan strain. With new variants we will need to constantly map the vaccine escape mutations that may come up, thus making the current vaccines less effective.

The B.1.617.2 strain referred to Delta variant is labeled a Variant-Of-Concern (VOC) by the WHO because of its transmissibility. Results indicate majority of the patients were affected by the new delta variant 617.2. Not only this strain, have we known from Gear-19 data that there are 8,572 variants found in India. We definitely need to ascertain which one of these is capable to create new waves assessing its clinical implications, transmissibility and fatality, he added.  

We know that many of these will lead to vaccine escape mutation in leading to us either requiring a booster or may be a completely new vaccine. Some of the mutations seen in the Delta variant also indicate reduced antibody efficacy and reduced neutralization by vaccine sera. For eg the Pfizer vaccine may not very effective against the 617.2 variant, he noted.

Vaccine policy and safety measures may need re-evaluation. The recent PGI, Chandigarh study showed the 1.6% of healthcare workers were infected despite having both doses of the vaccination. This may mean that social distancing measures may need to continue even after vaccination. As more vaccines enter the Indian market, they will need to continuously be evaluated with respect to the novel mutations and strains that are expected to emerge in the coming months, said Dr Rao.

The rise in cases a day shows more number of virus replications in a given time period, and hence the higher the chances of vaccine escape mutations arise. If this pattern of case increase continues, it is inevitable that such mutations will arise within a few months.   The most important application is that of getting advance notice of shifts in disease dynamics using genomic surveillance, he said.

There is no specific proof indicating the new variant to target only children. However, the conjecture comes from the fact that currently with vaccination covering those above 18 years, the only vulnerable population would be children where virus would potentially target as host. Nonetheless, all people who haven’t been vaccinated or partially vaccinated would still be vulnerable.

National Centre for Disease Control (NCDC), India, confirmed over 24,000 mutations in SARS-CoV-2 are recorded in India and over 8,500 variants were submitted to GISAID. The Delta variant- B.1.617 is of October 16, 2020, and our preparedness should have increased from then to February 2021, to prepare for 2nd new wave based on genomic surveillance. The B.1.617 has clearly contributing significantly to the second wave. There are more than 8,000 variants yet to be categorized.

Going forward, we need to ensure that systems for real-time genomic surveillance and preparedness for further waves, need to be strengthened, with such an unpredictable progress of the pandemic, said Dr Rao. PharmaBiz