India has seen a sharp rise in Covid-19 cases in March. Covid-19 cases registered a six-time jump in less than two months. Last week, India saw a gradual increase in active cases with 6,559 cases on March 20, 7,026 cases on March 22, 8,601 on March 25 and finally 10,300 active cases on March 27.
With an increase of 1,890 cases in a day, India's active caseload crossed the 10,000 mark, according to the Union health ministry data updated on Monday. The positivity rate also increased from 0.07% to 3.19% during this period.
The current active caseload of India stands at 10,981. As of now, Maharashtra (2212), Kerala (2662), Gujarat (1849), Karnataka (812), and Delhi (538) have seen the highest jump in daily cases, and have added significantly to the tally.
According to the experts, the rise in cases can be attributed to a new strain of Covid, known as the XBB1.16. BOOM spoke to them to know more about the latest strain of Covid-19.
What is XBB1.16?
According to the Indian SARS-CoV-2 Genomics Consortium (INSACOG), the XBB1.16 is a sub-lineage of the Omicron strain. Talking about the emergence of strain, virologist Shahid Jameel said, "The XBB and XBB.1 lineages are sub-lineages of the SARS-CoV2 Omicron Variant of Concern (VoC) that resulted from a recombination between two Omicron BA.2 lineages, BJ.1 and BA.2.75." XBB1.16 on the other hand is a new sub-lineage of XBB.1 which was first detected in India in mid-January and has since spread rapidly with over 600 confirmed cases, he added.
Narender Saini, microbiologist and chairman of the Indian Medical Association Antibiotic Resistance Committee said, "The SARS-CoV-2 or the coronavirus has undergone slight changes which led to the formation of a new strain which we call the XBB1.16. The coronavirus is very susceptible to these slight changes, or mutations, as it is an RNA virus." An RNA virus changes very frequently, unlike a DNA virus which is rather stable.
Speaking to BOOM, Manish Goel, director of Pulmonology at Fortis Hospital in Gurgaon, said the XBB1.16 strain has Omicron linkage but it does not have a fairly high transmission rate. "However, the mutations in viruses are a common thing but they eventually downscaled with time. This is a very common trend with viruses, the same happened with the Spanish flu," Goel said.
The Spanish flu was a pandemic caused by a new influenza A virus (H1N1) that spread easily and infected people throughout the world. As the virus was new, nobody had immunity to the disease. Around the world, the Spanish flu infected 500 million people between 1918 and 1919, which was roughly 33% of the entire world's population at the time.
Can it trigger a wave?
Saini explained that a wave occurs in two scenarios, if the virus transmits very fast and if the virus is new. "In this case, neither XBB1.16 has a high transmission rate, like Omicron, nor it is a new virus as it has mutated from the Omicron." Therefore it is very unlikely that it will cause another wave.
"We already have around 80% immunity against the virus, either by virtue of infection or by vaccination. The previously acquired immunity which we have is already strong enough, so the rate of transmission is rather slow," Saini added.
A large number of Indians and people globally have been infected with Omicron variants that could have given them widespread protection from disease as also infection to some extent. "Unless a drastically different variant from Omicron emerges, there is very little threat of new waves," Jameel said.
Speaking on why XBB1.16 may not cause a wave, Goel said that the new strain, though an Omicron lineage, is not a serious threat capable of causing wave like its predecessor. "We must worry only if a strain is life-threatening, it causes serious illness or leads to high hospitalisation rates. XBB1.16 is not contributing to any of these," he said.
Is Covid-19 an endemic now?
According to Saini, Covid-19 is no more a pandemic, but an endemic. Explaining the difference between the two, Saini said, "In an endemic, the virus remnants in the air are very small. As and when it gets an opportunity, it infects but in limited access. On the other hand, pandemic affects the entire world and not just a country." For a pandemic to occur there must be a new virus that has a high transmission rate which causes a sudden increase in infections, he added.
Endemics, however, can always turn into a pandemic. "We can stop the occurrence of a new wave or a pandemic if we do not allow a virus to linger for long. For this we must take the vaccines, maintain hand hygiene and wear masks," Saini said.
Endemicity is when a virus is marked by low levels of background infection and low mortality and India has achieved that. "According to the 7-day average for March 27, India accounted for 1,505 cases and 5 deaths with a mortality rate of 0.33%. If Covid mortality is approaching 0.1% in India, it's similar to seasonal flu, which is endemic," he added.
According to Goel, "Although there has been no official announcement by World Health Organisation or by the government that Covid is no more a pandemic, but we can say that it has been significantly weakened." He also suggested that adding another dose of vaccination after the third booster dose should be implemented by the government because our immunity will be decreasing over time. "Apart from this masking up helps a lot, therefore, it should be duly followed," he added.