New Delhi: Vimala Rani, a 70-year-old Delhi resident, has been getting a flu vaccine every year since 2023 when her doctor recommended it because she has diabetes and had been treated for breast cancer.
Her son, Pankaj Saluja, said the decision was largely about reducing her risk of serious complications from influenza. “She is diabetic and takes insulin. Considering all these things, because immunity gets down with all these illnesses, we decided to take the flu vaccine,” Saluja told ThePrint.
Since then, Vimala has not had any major flu-like illness, including during the current surge in H1N1 cases in Delhi. “We are now considering getting annual flu vaccines for the whole family,” Saluja said.
Families like Vimala’s are not very common in India, where despite availability of flu vaccines, uptake remains low. There is also no government-funded programme in India that routinely provides seasonal influenza vaccination.
Only 1.5 per cent of adults aged 45 years or older had ever received an influenza vaccine, according to data from the Longitudinal Ageing Study in India 2017-18. The low uptake, medical experts say, is due to a combination of factors, including limited awareness, the perception that influenza is usually a mild illness, and the cost of an annual vaccine. Typically, a flu vaccine is priced at around Rs 2,000 in the private sector.
Doctors ThePrint spoke to broadly agree that influenza vaccination can reduce the risk of severe disease, although it does not prevent every infection.
“Flu vaccines can provide between 40-60 per cent protection and can reduce the severity of illness and the risk of hospitalisation,” said Dr Dhiren Gupta, senior paediatrician and co-director, Paediatric Pulmonology, Sir Ganga Ram Hospital in New Delhi.
Public health expert Dr Chandrakant Lahariya said that even around 50 per cent effectiveness can translate into meaningful protection because influenza affects a large number of people in India.
No clear flu season
India does not have one clearly defined flu season. Influenza can circulate throughout the year, with patterns varying by region and major peaks often associated with the monsoon and winter. This makes vaccination timing and surveillance more complicated.
According to Dr Tarun Kumar, Director and Head, Medanta Moolchand Heart Center in New Delhi, the variable timing of influenza activity may also contribute to low uptake. “The viral illness is very variable in India, unlike the West. Sometimes it peaks in September, sometimes in October, sometimes in August,” Dr Kumar said.
H1N1, or influenza A(H1N1), is a subtype of influenza A virus that causes seasonal flu and spreads from person to person, mainly through respiratory droplets and aerosols. It can cause symptoms ranging from fever, cough and body aches to severe respiratory illness, particularly in vulnerable people.
Delhi recorded 2,602 influenza cases by 21 August this year, dominated by 2,392 influenza A infections, including 1,777 H1N1 cases, and 210 influenza B infections.
The Indian Council of Medical Research (ICMR) confirmed the spike stems from the known A/Missouri/11/2025 strain rather than a new or unusually dangerous variant. Observed genetic changes reflect normal antigenic drift, meaning circulating viruses remain well-matched to recommended Northern Hemisphere vaccines.
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Flu vaccines in India
The influenza virus was first isolated in humans in 1933-34, although large outbreaks had been described much earlier.
One of the most devastating was the 1918-19 influenza pandemic, which caused a massive number of deaths globally and also had a particularly heavy impact on India, said Dr Raj Shankar Ghosh, senior physician and public health expert, Public Health Foundation of India (PHFI).
The isolation of the virus helped drive efforts to develop vaccines against influenza. As the virus changes over time, vaccine formulations have also evolved to target the strains expected to circulate.
Several influenza vaccines are available in India through the private sector. These include inactivated trivalent vaccines, which target three influenza strains, and quadrivalent vaccines, which target four.
The Central Drugs Standard Control Organisation’s list includes influenza vaccines from manufacturers such as Abbott, GSK, Sanofi and Zydus.
However, the preferred composition has been changing. For the 2026-27 Northern Hemisphere season, the recommended trivalent vaccine protects against influenza A(H1N1), H3N2 and influenza B/Victoria. “The move towards trivalent vaccines follows the absence of the B/Yamagata lineage from global surveillance for several years,” said Dr Lahariya.
He explained that flu vaccines are manufactured based on the World Health Organisation (WHO) recommendations about the strains expected to circulate during a particular season. The composition is selected using surveillance data, and vaccines take time to manufacture, meaning the formulation available at a particular point in the year reflects viruses identified earlier in the process.
“The vaccine needs to be taken every year because influenza viruses continually undergo genetic changes and immunity from vaccination also declines over time,” explained Dr Kumar.
The groups most consistently prioritised by medical bodies include older adults, young children, and pregnant women. “It is also recommended for those with coronary artery disease or heart failure, diabetes, chronic lung diseases such as Chronic Obstructive Pulmonary Disease (COPD) and asthma, and people undergoing chemotherapy,” said Dr Kumar.
He explained that since flu is self-limiting in most cases, in these high-risk groups it can lead to complications that can be life-threatening. Healthcare workers are also considered a priority group by WHO because of their increased exposure to influenza and the possibility of transmitting the virus to vulnerable patients.
The Indian Academy of Pediatrics recommends annual influenza vaccination from six months of age, with routine vaccination through five years of age. For children receiving the vaccine for the first time, two doses are generally given four weeks apart, followed by one dose every year.
For adults and older people, the vaccine is generally given as a single annual dose.
If someone is already suffering from H1N1 in this season, vaccination is generally postponed until they recover. Once recovered, vaccination can be discussed with a doctor, particularly if belonging to a high-risk group.
A flu vaccine does not protect against every respiratory illness. It specifically protects against influenza viruses, not diseases such as dengue or pneumococcal disease, which requires a separate pneumococcal vaccine.
Everyone generally needs just one annual dose of the flu vaccine, except for children receiving the flu vaccine for the first time between 6 months and 8 years old. They need two doses given at least 4 weeks apart.
The timing is important because protection takes about two weeks to develop. WHO recommends vaccination before the period when influenza activity is expected to increase, although getting vaccinated later can still provide protection.
“Every individual who is eligible for these vaccines should be given information about these vaccines to make an informed choice,” Dr Lahariya said.
He added that people should understand the vaccine’s limitations, including that it does not completely prevent infection but can reduce the risk of severe disease.
Not part of Universal Immunisation Programme
India’s Universal Immunisation Programme has traditionally focused on vaccines given to pregnant women, infants and children against diseases that cause substantial morbidity and mortality. Influenza is not part of the National Immunisation Schedule.
The question, however, is whether India has enough evidence on disease burden, vaccine effectiveness and costs to justify spending public money on an annual vaccination programme for flu.
Disease burden includes not just deaths, but also illness, disability, hospitalisations and financial costs. Dr Ghosh said such evidence can justify government-funded vaccination when the burden is high enough.
He cited pneumococcal disease, an infection caused by the bacteria Streptococcus pneumoniae that can lead to pneumonia, meningitis and other serious illnesses, where evidence on fatalities and hospitalisations supports free vaccination for vulnerable groups.
For influenza, however, he said evidence to justify adding the vaccine to the adult immunisation schedule is still lacking.
“India needs much stronger evidence before introducing influenza vaccination for vulnerable populations through a government programme,” Dr Ghosh said. He said this should include better surveillance and stronger Indian data on influenza’s burden on the healthcare system, vaccine effectiveness and mortality.
“With the lack of proper evidence within India, we really should not quote any figure,” Dr Ghosh said when asked about influenza’s case-fatality rate.
This is particularly relevant because influenza deaths can be difficult to capture.
Many patients are not tested for influenza, while the virus can worsen underlying conditions such as heart disease, diabetes or chronic respiratory disease.
Dr Lahariya said not every person with a respiratory illness needs to be tested because testing often does not change treatment. Cases that are hospitalised or require specialised care are more likely to be tested.
Nevertheless, there is emerging evidence that vaccination could make economic sense.
A 2025 cost-benefit analysis found that vaccinating healthy adults and pregnant women with a quadrivalent influenza vaccine could reduce healthcare resource use and improve productive days. The researchers estimated savings of Rs 13,730 per case averted from a corporate perspective and Rs 11,211 from the Employees’ State Insurance Corporation perspective.
Another study published in April 2026 examined seasonal influenza vaccination among people aged 60 and above. It estimated that this group experienced 5.3 million influenza-associated acute respiratory infections in 2021, resulting in about 36,000 hospitalisations and 84,600 deaths. The analysis found that vaccinating older adults was cost-effective in most scenarios.
Existing research also suggests that partnerships with the private sector could help improve access to influenza vaccination.
The Unified Consensus on Adult Immunization 2026 recommends influenza vaccination for people with chronic diseases or weakened immunity, smokers and alcohol consumers, those travelling or attending mass gatherings, and adults above 50.
India’s ageing population adds another reason to examine the issue. People aged over 60 are projected to account for about 15 per cent of the population by 2036, up from 12 per cent in 2021.
Dr Lahariya, however, said the evidence does not yet support a mass government-funded vaccination programme.
“Government resources are limited and need to be directed towards interventions where the public-health benefit is strongest,” he added.
(Edited by Nardeep Singh Dahiya)