1 / 9Former AIIMS-Delhi Director Dr Randeep Guleria spoke on the rise in influenza cases caused by the H3N2 virus.2 / 9The Chairman of the Institute of Internal Medicine and Respiratory and Sleep Medicine and Director of Medical Education said that with the festive season just around the corner, people should be careful, especially especially the elderly and those who have underlying comorbid conditions. 3 / 9Talking to news agency ANI, Dr Randeep Guleria said the influenza cases present as fever accompanied by sore throat, cough, body aches and runny nose. He added there is a rise in cases because the virus mutated and people's immunity against it has become reduced.4 / 9'We had a pandemic many years ago because of H1N1. The circulating strain of that virus is now H3N2 and, therefore, it is a normal influenza strain. But we are seeing more cases because as the virus mutates a little bit, the immunity that we had against the virus becomes a little less and therefore people who are susceptible tend to get infection more easily,' Dr Guleria told ANI.5 / 9Dr Guleria further said that the virus changes slightly every year. He explained that the H3N2 virus comes from a family of influenza viruses which mutates depending upon its various subtypes. The virus mutates or changes slightly every year, in what is known as antigenic drift, he added.6 / 9The former AIIMS chief said he does not think there is that much of a cause of concern because the rise in cases has not been accompanied by increased hospitalisation to a large extent.7 / 9Dr Randeep Guleria said the rise in cases can be attributed to two things - there is a higher chance of getting influenza when the weather changes during this time of the year and people not wearing masks in crowded places post Covid.8 / 9The way to prevent ourselves from catching the virus is wearing masks in crowded places, said Dr Randeep Guleria. 'We also need to wash our hands frequently and also have physical distancing,' he added. According to Dr Randeep Guleria, there is also a vaccine for high-risk groups and the elderly.9 / 9He said it is okay to celebrate Holi but people should be careful, 'especially the elderly and those who have underlying comorbid conditions like chronic respiratory diseases, heart problems, kidney problems or undergoing dialysis'.