Ajay Barman, a 27-yearold automobile mechanic in Matigara near Siliguri, hasn’t gone to work since 28 July. He’s determined to stop the “deadly Delta variant” from spreading among members of his family and remains indoors for most of the time along with his wife, father and two daughters.

“I heard last month that the Delta virus is very dangerous. Even vaccines don’t work against it. My friends told me on Tuesday that many patients suffering from the Delta virus have been found in our Darjeeling district. I don’t want to get infected and die along with the rest of my family,” he grimaced. Like Ajay, many residents of north Bengal and Sikkim are living in fear of the Delta variant of the coronavirus after a large number of samples from this region tested positive for the Delta strain recently.

While many people in the region are thinking that they are getting ahead of the coronavirus outbreak and could relax, the news of the detection of 97 cases of Delta variant in Sikkim on 18 July and 14 Delta strains and three UK variant cases in north Bengal on 27 July has created panic among many residents here. In many social media posts, it is being increasingly and wrongly claimed that a large number of cases of the “Delta plus variant” has been reported from north Bengal and Sikkim.

However, the medical superintendent and vice-principal of the North Bengal Medical College and Hospital, Dr Sanjoy Mallick, who regretted the confusion caused by the news of the detection of the Delta variant in north Bengal and Sikkim, told this correspondent today that the Covid-19 positive samples, in which the Delta and the UK strains of the virus were found, were collected from infected patients in April and May this year.

“Delta is the strain that was almost singularly responsible for the deadly second wave of infections this summer in India. It is also thought to have driven the deadly second wave in our region. So the detection of the variant in many of the samples, which were sent for genome sequencing earlier this month to the National Institute of Biomedical Genomics in Kalyani, is nothing surprising and should not be a cause of fear for the residents of Sikkim or north Bengal,” he said.

Dr Mallick, who is also a senior professor at the department of Microbiology in the NBMCH, said that viruses mutate all the time and most changes were inconsequential.

“All mutations are not significant. But some mutations can make the disease more infectious or threatening, and these mutations tend to dominate, as the Delta variant did during the second wave in India,” he said. The senior microbiologist noted that a mutation was elevated from a “variant of interest” to a “variant of concern,” when it shows evidence of fulfilling at least one of several criteria, including easy transmission, more severe illness, reduced neutralization by antibodies or reduced effectiveness of treatment and vaccines.

“India has classified Delta Plus, a new variant of the coronavirus first identified in the country, as a variant of concern, but it is too early to say whether it poses a significant threat. The World Health Organization has categorized the variant-also known as AY.1-as a variant of interest and no case of this variant has so far been reported from north Bengal or Sikkim,” he categorically stated. Dr Ranadhir Chakraborty, a senior professor of the Department of Biotechnology, University of North Bengal, who agreed with Dr Mallick, said that variations were a common phenomenon in the life of a virus as in the life of all living beings on earth.

“The fear about the various variants of the coronavirus is totally baseless and unwarranted. People should understand that without mutations no organ or organism can survive. It is because of mutation that no two human beings are identical and almost all human beings are born with some congenital defects,” he said. Dispelling the fear created among the masses in north Bengal regarding the detection of the Delta and the UK variants here, Dr Chakraborty said that mutations were a natural and obvious process that occurs during the replication of a virus after entering into an appropriate human cell.

“When a virus enters into a human body, a struggle begins between the body and the virus. If and when the virus overpowers the human body, the virus begins to infect the body through replication, that is, through the process of formation of biological viruses during the infection process in the target host cells. Due to errors in this replication, mutations are recruited in the genome of the virus.

Some of these mutations are advantageous to the virus because they lead to a favourable change for the virus, which confer new attributes on the virus like an increase in the propensity of infection, rate of replication and reproductive efficiency. The duration of replication in some cases may be very short and its manifestation as a disease may be quick, but it should not be a cause for confusion or panic at all as against all variants the treatment regimen remains equally effective,” he assured.