Influenza vaccine: Benefits, who should get a flu shot, and vaccination schedule

A clear guide to the influenza vaccine in India: who needs it, how often to get it, what the benefits are for seniors, and how to get vaccinated at home.

The influenza vaccine is an annually updated inactivated vaccine that stimulates the immune system to produce protective antibodies against the predominant circulating strains of the influenza virus, including H1N1 and H3N2, reducing the risk of flu illness, hospitalisation, and serious complications, particularly in high-risk groups including elderly adults, young children, pregnant women, and those with chronic health conditions.

Influenza is not a bad cold. It's a respiratory infection that spreads rapidly, can worsen quickly in vulnerable individuals, and causes hundreds of thousands of hospitalisations globally every year. Most people who get seriously ill from influenza didn't think they were at particular risk. The flu vaccine doesn't eliminate that risk, but it significantly reduces it, and for high-risk groups, the difference between vaccinated and unvaccinated outcomes is clinically meaningful.

This guide covers who should get the flu vaccine, how often, what the benefits are particularly for seniors, and how to get vaccinated at home through Apollo Homecare.

What is the influenza vaccine and how does it work?

The influenza virus mutates rapidly. This season's circulating strains are not identical to last year's, which is why the flu vaccine is reformulated annually to match the strains expected to be most prevalent. Once administered, it typically takes about two weeks for the immune system to produce the antibodies needed to fight the virus.

Apollo Homecare offers the Influvac Tetra, a quadrivalent influenza vaccine that protects against four strains of the influenza virus, including H1N1 and H3N2. It costs Rs. 2,499, including home visit and administration charges.

According to the World Health Organisation, seasonal influenza causes 3 to 5 million cases of severe illness and 290,000 to 650,000 respiratory deaths globally every year. Annual vaccination is the most effective preventive measure available.

Who should get the influenza vaccine?

The WHO recommends that everyone aged 6 months and older should be vaccinated against influenza annually. In practice, vaccination is particularly important for:

1. Adults over 60: Older adults are at higher risk of severe influenza complications including pneumonia, secondary bacterial infections, and hospitalisation. The immune system's reduced response to infection with age makes both the disease and its complications more dangerous.

2. People with chronic health conditions: Adults managing diabetes, heart disease, COPD, kidney disease, or conditions that affect immunity are at significantly higher risk of severe influenza and should be vaccinated regardless of age.

3. Pregnant women: Influenza during pregnancy carries risks for both the mother and the unborn child. Vaccination is safe during pregnancy and provides the newborn with some passive immunity during their first months of life.

4. Young children: Children under five, particularly those under two, are at high risk of severe influenza complications. Vaccination is recommended annually from six months of age.

5. Healthcare workers and caregivers: Those who work with or care for high-risk individuals reduce the risk of transmission by staying vaccinated themselves.

6. Adults with no specific risk factors: Even for healthy adults, influenza causes significant illness, missed work, and disruption. Annual vaccination is a practical preventive step for anyone who wants to reduce that risk.

What are the benefits of the influenza vaccine?

1. Reduces the risk of flu illness: Vaccination significantly reduces the likelihood of contracting influenza during the season, particularly against the strains the vaccine targets.

2. Reduces severity if you do get flu: Even partial immunity means that vaccinated individuals who do contract influenza experience milder symptoms, recover faster, and are less likely to develop serious complications.

3. Reduces hospitalisation risk: For elderly adults, people with chronic conditions, and pregnant women, the reduction in hospitalisation risk is one of the most clinically significant benefits. Flu-related hospital admissions in these groups are common and preventable.

4. Protects those around you: Vaccination reduces transmission. Getting vaccinated is not just a personal health decision. It reduces the risk of infecting elderly family members, young children, and immunocompromised individuals who may be more vulnerable.

5. Safe during pregnancy: The influenza vaccine protects the mother during pregnancy and provides passive immunity to the newborn in their first months of life, before they are old enough to be vaccinated themselves.

For a more detailed look at the influenza vaccine and how it works, read Apollo Homecare's guide: Understanding the influenza vaccine and why it matters.

How often should the flu shot be taken?

Annually. The influenza virus mutates quickly enough that last year's vaccine provides little to no protection against this year's circulating strains. A new vaccine is formulated each year based on WHO surveillance of which strains are most likely to dominate the coming season.

The best time to get vaccinated is before the flu season peaks, ideally before or during October. That said, vaccination at any point during the season still provides meaningful protection. If you missed the optimal window, getting vaccinated later is still worthwhile.

What are the benefits of the influenza vaccine specifically for seniors?

For adults over 60, the influenza vaccine is one of the most impactful preventive steps available. The immune system weakens with age, so older adults are more likely to contract influenza and more likely to develop serious complications when they do.

Complications in elderly patients include pneumonia, secondary bacterial infections, exacerbation of chronic conditions like COPD and heart failure, and hospitalisation that can trigger a prolonged period of functional decline. Vaccination meaningfully reduces all of these risks. For elderly patients who already find clinic travel difficult, Apollo Homecare's at-home flu vaccine service removes the last logistical barrier to getting vaccinated.

What are the common side effects of the flu vaccine?

Most people tolerate the influenza vaccine well. Common side effects are mild and localised to the injection site: soreness, redness, or mild swelling that typically resolves within a day or two. Some people experience temporary fatigue, a mild headache, or a low-grade fever. These are normal immune responses and are not a cause for concern.

A common myth is that the flu vaccine can give you the flu. This is not true. The Influvac Tetra is an inactivated vaccine containing killed viral components that cannot cause influenza infection.

Severe allergic reactions are rare. Inform your healthcare professional before vaccination if you have a known allergy to any vaccine component or are currently unwell.

Can the influenza vaccine be administered at home?

Yes. Apollo Homecare's flu vaccine at home service brings a trained healthcare professional to your residence to administer the Influvac Tetra vaccine, including home visit and administration charges, for Rs. 2,499. The vaccine is transported under cold-chain conditions with temperatures maintained between 2°C and 8°C from dispatch to doorstep administration.

This is particularly suited to elderly patients, those with mobility limitations, families with young children, or anyone who prefers not to visit a clinic for a routine annual vaccination. For a complete overview of all vaccines available at home, read our guide: Vaccination at home: how it works, benefits, and how to book.

Book your flu vaccination at home today. Visit apollohomecare.com or call 1800 108 8586. Available across Hyderabad, Bangalore, Chennai, Delhi NCR, Kolkata, Mumbai, Pune, Madurai, Mysore, Indore, and Guwahati.

Frequently asked questions

1. Who should get the influenza vaccine?

The WHO recommends annual flu vaccination for everyone aged 6 months and older. The groups where it matters most are adults over 60, people with chronic conditions, pregnant women, young children, and anyone who lives with or cares for someone in a high-risk group. For healthy adults, it's a practical step to avoid a week of significant illness every year.

2. How often should the flu shot be taken?

Every year, without exception. Last year's vaccine doesn't cover this year's strains. The reformulation cycle exists precisely because the virus mutates fast enough that annual protection is the only reliable approach. Missing a year means going unprotected for an entire season.

3. What are the benefits of the influenza vaccine for seniors?

Beyond the obvious reduction in flu risk, the vaccine reduces the risk of complications that disproportionately affect older adults: pneumonia, exacerbation of existing chronic conditions, and the hospitalisation that often follows. For elderly patients already managing multiple conditions, a flu infection can destabilise a carefully managed health picture in ways that take months to recover from.

4. Can the influenza vaccine be administered at home?

Yes. Apollo Homecare offers the Influvac Tetra flu vaccine at home at Rs. 2,499, inclusive of the home visit and administration. A trained healthcare professional arrives at your residence, administers the vaccine under cold-chain protocol, and provides post-vaccination guidance before leaving.

5. What are the common side effects of the flu vaccine?

Soreness at the injection site, mild fatigue, and occasionally a low-grade fever for a day or two. These signs show your immune system is responding, not that something is wrong. The vaccine cannot cause influenza. That's a persistent myth with no clinical basis.

Disclaimer: This article is for general informational purposes only and does not constitute medical advice. Vaccine suitability varies by individual health history. Please consult a qualified healthcare professional before getting vaccinated.