NEW DELHI: Amid the Covidpandemic, doctors and experts are advising people of all age groups to take a flu shot as a primary protection against other respiratory viral illnesses like common seasonal flu and H1N1 – some of which can cause pneumonia and make people vulnerable to coronavirus.
Influenza or flu is a viral disease caused by the influenza viruses. The disease affects the respiratory system and causes symptoms like cough, fever, sore throat, tiredness, muscle pain and a runny nose. Pneumonia is one of the complications of the flu, along with sinus and ear infections which are common among infants and elderly. A flu shot, emphasise experts, is no protection against Covid, but will work to reduce illnesses that often have similar symptoms.
“Covid-19 has brought to fore the importance of preventing other respiratory viral illnesses. Unfortunately, vaccination against flu has not been a common practice or popular in our country. Now is the time to relook at and popularize this vaccine against the flu virus especially in the vulnerable population,” says Dr Sudarshan Ballal, Chairman, Manipal Hospitals.
Flu vaccines – very common in western countries – usually do not have a very high level of efficacy as it needs to match particular strains which keep changing almost every year. The shots have to be taken yearly since the flu virus changes its genetic material. A new or updated vaccine that targets the new strains of the virus is needed to provide continued protection from the disease.
“WHO holds a meeting every year where experts predict three important strains based on the patterns of virus seen through the year. The vaccine manufacturers then start making vaccines based on these predictions,” says Gagandeep Kang, a clinical scientist who played a key role in development of India’s first local vaccine Rotavac against rotavirus.
Some feel the latest version of the flu shot should be awaited. “The new vaccine should become available in the next couple of weeks and it would be prudent to wait for this vaccine. Seasonal flu can produce significant morbidity in certain individuals – the elderly, those with compromised immune systems and chronic lung conditions. With Covidpandemic, it is important not to forget to protect these selected sub groups of individuals from influenza,” says Anupam Sibal, Medical Director and Senior Pediatric Gastroenterologist at Apollo Hospitals.
While the efficacy of a flu vaccine ranges anywhere between 20-70% depending on how close or accurate the predictions are to the actual mutation of the virus, experts say in the current scenario it is worth it because it can reduce hospitalization and deaths among vulnerable population from severe pneumonia and other respiratory illnesses. “If you were to be in a situation to prevent 30% hospitalization by using a vaccine, why would you not do it. It will save lives and resources that can be used for Covidpatients,” says Kang.
In the Unlock-3 phase, when people have increasingly started coming out with activities picking up fast, flu vaccine is seen as a major protection against seasonal influenza that picks up with the onset of monsoon and winters.
There were some initial studies that suggested that flu vaccine may protect one from getting a severe Covid-19 infection by improving innate immunity. Researchers in Brazil found that a flu shot can reduce mortality by 20% when taken before the onset of Covid-19 and about 27% when the vaccine was given after.
This article was published in TOI on 11 Aug 2020