Adult vaccination: which vaccines adults need, and why

Why does adult vaccination get overlooked in India?

India runs one of the largest childhood immunisation programmes in the world, and it works. Adult vaccination has no equivalent public programme, so it falls to individual consultations, and in practice it rarely comes up: the patient does not ask, and a busy outpatient visit is spent on the complaint that brought them in. The result is that a person with twenty years of type 2 diabetes will have had their HbA1c checked sixty times and never once been asked whether they have had a pneumococcal vaccine.

A word on a statistic you may encounter. It is frequently claimed that 95% of vaccine-preventable deaths in India occur in adults. That figure has been repeated across review articles for years, and when traced backwards it terminates in a 2008 newspaper report; the citation chain does not lead to any Indian dataset. It is not used on this page. The case for adult vaccination is strong enough on properly sourced evidence, which is what follows.

Which vaccines do adults in India actually need?

Six vaccines account for the great majority of adult vaccination. The table below is a summary, not a prescription — the right schedule for any individual depends on their conditions, medicines, pregnancy status and what they have already received.

Why is the influenza vaccine given every year?

Two separate reasons, often confused. The first is that influenza viruses drift: the surface proteins the immune system recognises change enough from season to season that last year's antibodies match this year's virus imperfectly, and the vaccine composition is reformulated accordingly. The second is that protection from a single dose wanes measurably over the course of one season. Neither means the previous dose failed.

The vaccine is a moderate performer, and it is worth being straightforward about that. In well-matched seasons, influenza vaccination reduces the risk of a flu-related medical visit by 40–60% in the general population.^[1] Against hospitalisation in adults aged 65 and over, a systematic review across five European seasons found effectiveness of about 40%,^[2] and US surveillance for the 2023–24 season put it at 42%.^[3] A vaccine that halves your chance of a bad outcome is not a wall; it is a substantial shift in the odds, repeated annually.

When is the influenza season in North Bengal?

This matters more in Cooch Behar than most people assume. India does not have the single sharp winter influenza peak seen in Europe and North America. In the tropical and sub-tropical belt, transmission tracks the monsoon, and much of the country sees a substantial rainy-season peak between roughly June and September, with a smaller winter wave in some northern regions.^[4] The practical implication is that timing a flu shot to a northern-hemisphere October calendar may miss the local peak entirely. Timing is discussed at the consultation rather than fixed by a rule.

What does influenza vaccination do for someone with diabetes?

This is the strongest single argument for adult vaccination in an Indian general medicine practice, because India has an estimated 101 million adults with diabetes.^[5] Two large cohort studies are worth quoting precisely.

In a Danish nationwide cohort of 241,551 adults on glucose-lowering medication, followed across nine influenza seasons, vaccination was associated with 17% lower all-cause mortality (hazard ratio 0.83, 95% CI 0.78–0.88) and 16% lower cardiovascular mortality.^[6] In an English primary-care cohort of 124,503 adults with type 2 diabetes, vaccination was associated with fewer hospital admissions for stroke (30% lower), heart failure (22% lower) and pneumonia or influenza (15% lower), and with 24% lower all-cause mortality.^[7]

Two caveats belong with those numbers rather than in a footnote. Both are observational studies, so they show association, not proof of cause; people who accept vaccination differ systematically from those who do not, and no statistical adjustment fully removes that. And in the English study the reduction in myocardial infarction admissions did not reach statistical significance (IRR 0.81, 95% CI 0.62–1.04) — you will see “19% fewer heart attacks” quoted from this paper, and that specific claim is not supported by it.

Is there a real link between influenza and heart attacks?

Yes, and it is one of the more striking findings in the field. A self-controlled case-series study in Ontario linked laboratory-confirmed influenza infections to hospital admissions for acute myocardial infarction, and found the risk of a heart attack was 6.05 times higher in the seven days following confirmed influenza than in the comparison period (95% CI 3.86–9.50).^[8] The design is elegant because each patient is their own control, which removes confounding by individual risk factors. The caveats are that it applies to laboratory-confirmed influenza rather than any winter illness, and that only 20 events fell inside the seven-day window — a large relative risk built on small absolute numbers.

On the other side of the equation, a meta-analysis of five randomised trials in 9,059 patients with established cardiovascular disease found influenza vaccination associated with 26% fewer myocardial infarctions (RR 0.74, 95% CI 0.56–0.97).^[9] The same analysis found no significant effect on stroke in this population — a figure of “30% fewer strokes” circulates widely and belongs to the diabetes cohort above, not to cardiac patients.

Which pneumococcal vaccine, and how many doses?

Lower respiratory infection remains the leading infectious cause of death worldwide, with an estimated 2.50 million deaths in 2023, and the burden falls disproportionately on children under five and adults over 70.^[10] Pneumococcus is the commonest bacterial cause in adults.

Adult pneumococcal vaccination has become simpler. The 20-valent conjugate vaccine, PCV20, covers twenty serotypes in a single dose and — unlike the older 13-valent and 15-valent products — does not require a follow-up polysaccharide dose in adults who have not been vaccinated before. In October 2024 the US Advisory Committee on Immunization Practices lowered the routine age for adult pneumococcal vaccination from 65 to 50.^[11] PCV20 received Indian import permission in November 2024 and became commercially available for adults in August 2025; it is a private-market vaccine and not inexpensive. Anyone who has previously received PCV13 or PPSV23 still has a place in the schedule, but the interval differs, which is why the vaccination history matters.

How well does the shingles vaccine work, and for how long?

Recombinant zoster vaccine (Shingrix) is unusually effective for a vaccine given to older adults. In the ZOE-50 trial it prevented 97.2% of shingles cases in adults aged 50 and over (95% CI 93.7–99.0);^[12] pooled ZOE-50 and ZOE-70 data gave 91.3% in adults aged 70 and over.^[13] It was licensed in India in April 2023 for adults aged 50 and above.

The figure quoted in most marketing is “over 90%”, and that is true only for the early years in people with normal immunity. Long-term follow-up shows efficacy declining to about 73% by year ten,^[14] and in immunocompromised groups it is substantially lower from the start — 68.2% after autologous stem-cell transplant, for instance.^[15] It is still a very good vaccine. It is not a permanent one.

Why is hepatitis B vaccination raised with people who have diabetes?

Because of a specific and often over-stated finding. US surveillance data showed that adults aged 23 to 59 with diabetes had about twice the odds of acute hepatitis B compared with adults without diabetes (odds ratio 2.1, 95% CI 1.6–2.8) — but in adults aged 60 and over the same analysis found no statistically significant increase (OR 1.5, 95% CI 0.9–2.5).^[16] The mechanism proposed was shared glucose-monitoring equipment. The blanket statement that “diabetics have double the hepatitis B risk” drops the age band, which is the part that changes what you do.

In any case the recommendation has since broadened past diabetes: since 2022, universal hepatitis B vaccination is advised for all adults aged 19 to 59 regardless of risk factors.^[17]

Is HPV vaccination only for girls?

No. HPV causes cancer at a minimum of six sites — cervix, oropharynx, anus, penis, vagina and vulva — and in current US data the oropharynx, a site affecting mostly men, has overtaken the cervix as the commonest HPV-associated cancer site.^[18] In India the cervical burden remains very large: cervical cancer is the second most common cancer in Indian women, with 127,526 new cases recorded in GLOBOCAN 2022.^[19]

Where care is needed is the upper age band. Vaccination is routine to age 26. Between 27 and 45 it is not a routine recommendation but a shared clinical decision — benefit is lower because many adults have already been exposed to the common types, and whether it is worthwhile depends on the individual's circumstances.^[20] The 2026 Indian consensus update takes a somewhat more permissive line for this age band than the US guidance does. Either way, it is a conversation, not a default.

Which vaccines are needed for travel, and for Hajj or Umrah?

Saudi Arabia requires a valid quadrivalent meningococcal ACWY certificate from all Hajj, Umrah and seasonal-worker arrivals aged one year and over, administered at least ten days before arrival. A conjugate vaccine certificate is valid for five years and a polysaccharide certificate for three; if the certificate does not state which type was given, it is treated as valid for three years only.^[21] That last detail catches people out, so the vaccine type is recorded explicitly on any certificate issued here.

One thing this clinic cannot do: yellow fever. In India, yellow fever vaccination and the International Certificate of Vaccination or Prophylaxis may only be issued at centres designated by the Directorate General of Health Services under the International Health Regulations, and all of the designated centres are government facilities.^[22] If you are travelling to a yellow-fever country you will be directed to the nearest designated centre. Since July 2016 a yellow fever certificate is valid for life, so an old one may still be current.

How is an adult vaccination plan actually decided?

By taking a history, which sounds obvious and is the step most often skipped. What is asked: age; existing conditions, particularly diabetes, chronic kidney disease, heart failure, COPD, liver disease and asplenia; current medicines, especially steroids, immunosuppressants and chemotherapy; pregnancy or planned pregnancy; allergy history, particularly to a previous dose; occupation and any household contact who is immunocompromised; travel plans; and every vaccine already received, with dates where they exist. Any doses given are recorded so that intervals and boosters can be tracked, since the schedule for several of these vaccines spans months or years.

A note on the Indian guidance most often cited here. The Indian Consensus Guidelines on Adult Immunization: 2026 Update was released on 5 March 2026 with 23 collaborating professional associations. It is a consensus document published by the Association of Physicians of India Maharashtra State Chapter together with IMA Mumbai West — it is not a peer-reviewed or PubMed-indexed guideline, and it is used on this page as consensus opinion rather than as primary evidence.^[23]