Swine flu's tendency to mutate leads to rise in cases

After the H1N1 virus mutation last year, experts had confirmed that the disease was not seasonal anymore. The 'California' strain of the disease has existed since 2009, while the 'Michigan' strain was discovered in early 2017.

A total of 38,811 people across in the country while 2,835 in the national Capital had fallen prey to the swine flu last year, which claimed 2,266 and 12 lives, respectively. There was a 21 fold increase in the number of cases as compared 2016 when only 1,786 cases were reported countrywide.

"The biggest problem with the Swine Influenza virus is its tendency to mutate. This is the survival mechanism of the virus to escape the human immune system and surpass the antibodies created by a human body. So, medicines and treatments for it are not long-lasting and need to be updated almost every year," said Dr Soumya Swaminathan, Director General, Indian Council of Medical Research (ICMR).

Keeping the mutations in mind, the government had changed the swine flu drug category from Schedule 'X' to Schedule H1, which means that the drug is now available at any registered chemist shop and can be procured with a doctor's prescription.

"The internationally available vaccines contain three inactivated viral strains, the composition of which is reviewed every six months to ensure protection against the strains prevailing in each influenza season. The composition of vaccines is adjusted for the hemisphere in which it will be used," the WHO website states.

Initially recorded in 2009 in Mexico, the disease was declared a pandemic by the World Health Organisation (WHO) in 2010. India had already witnessed 42,592 cases and 3,000 deaths by the end of 2010, as recorded. The death toll has gone up to 8,000 now.

"Most of those who succumbed are children, elderly, pregnant women or people with chronic lung disease. I strongly recommend that at least the vulnerable population, especially the healthcare workers, must take these vaccines to prevent the infection from spreading further," Dr Swaminathan added.

Earlier, the virus attacked mostly in winters. The WHO has been modifying vaccines separately for Northern and Southern Hemisphere. But in India, due to its position along the equator and after the recent mutations, both types of vaccines are made available at different times.