As the Delta variant mutates further, does India need to be concerned ?The current rise in cases in the United Kingdom shows traces of a sub-lineage of the Delta variant
Contd from previous issue
The findings prompted the city authorities to inform the Bombay High Court on October 4 that they do not anticipate a third wave to hit Mumbai.
Countries like China, New Zealand, which saw a fresh surge in October, and Singapore, Russia, that reported a rise in Covid-19 cases since September, attributed the spike to Delta variant. But Dr Hemant Deshmukh, Dean in KEM hospital, Mumbai, said the Delta variant is of little concern in India because a large population was exposed to it during the second wave. “We are seeing deaths only in a highly comorbid population,” he said.
However, Dr Rajesh Pandey, a scientist with CSIR Institute of Genomics and Integrative Biology expressed caution against Delta’s sub-lineages. “We don’t know at this point whether or not any of those derivatives end up being of concern,” he said.
According to the Israel Health Ministry, the AY.4.2 sub-lineage of Delta is 15% more transmissible than the Delta variant. So far, UK, US, Russia, Israel, parts of Europe and Asia have reported AY.4.2.
One of the mutations in AY.4.2 is K417N, also found in the Beta variant, which helps the virus evade immune response and infect a person. Another mutation, A1711V, helps in viral replication. Two other mutations, Y145H and A222V, are in the spike proteins of the virus, making its entry into the host cell easier.
In India, a few cases of AY.4.2 have been recorded. Out of 30 positive cases in Army cantonment in Indore, seven tested for AY.4.2 variant. Chief Medical Officer Dr BS Saitya told Scroll.in that all infected people had mild symptoms.
Maharashtra, Karnataka, Andhra Pradesh, Kerala, Telangana, Jammu and Kashmir have also reported AY.4.2 but not recorded a significant jump like UK did in the past few weeks.
Dr Anurag Agrawal, Director of the CSIR Institute of Genomics and Integrative Biology, said there is no current cause of concern with AY.4.2 and the “risk seems overstated”, at least for India. Dr Pandey of the same institute said they are closely monitoring its spread. “No red signal yet. Unless we see a substantial increase in the percentage of cases, there is no need to worry,” he said.
On October 26, addressing a press conference in New Delhi, Health Minister Mansukh Mandaviya said experts within the Government are examining the risk posed by AY.4.2, but declined to comment further.
Important to continue surveillance
Virologist Kang said India needs to continue its surveillance and closely monitor upcoming variants. Vaccination will reduce viral transmission speed thereby slowing its evolution, but not completely stop it, which means variants will keep turning up in future.
“We first saw Alpha six months before it became a problem, we also saw Delta six months before it started spreading fast,” she said. “India’s genome surveillance has improved but we need a serious effort to link epidemiological and genomic data to preempt whether an upcoming variant can spread.”
Although they are unwilling to put a timeline to this, most experts believe the virus will become endemic soon, which means there will be regular localised and seasonal outbreaks, just like H1N1 and Dengue. The future waves of Covid-19 will be localised, with small peaks. Kang said before that point is reached, drawing a constant correlation between epidemiological, genomic, and clinical data will provide a safe passage to countries.
Epidemiologist Reddy said,“Unless a major variant comes, the future will see a milder form of Covid-19 coexist with humans.”
Reddy explained that once the Delta variant hits a barrier in the form of the total vaccinated population, the virus will mutate to escape immune response in order to survive. He predicted that newer variants will be milder. “See H1N1 for instance. In 1919, it killed millions, but when it made a comeback in 2009 it didn’t kill as many people. Even coronaviruses will strive to settle down in the human population,” he said.
This reporting was supported by a grant from the Thakur Family Foundation. Thakur Family Foundation has not exercised any editorial control over the contents of this article.