Four Things to Know Before Taking Your Parents for Influenza Vaccination

As the weather turns cooler, messages like “It’s time for the flu shot” start circulating in WeChat groups and family chats. Yet when people actually arrive at vaccination clinics, many immediately ask: Should we get the trivalent or quadrivalent vaccine this year? Can my dad get vaccinated given his high blood pressure? What’s the latest month to get the shot? Here are clear answers to these questions to read before taking your parents to get vaccinated.

Question 1: How to choose between trivalent and quadrivalent vaccines?

Conclusion first: Trivalent vaccines are the main recommendation in China this year. Quadrivalent vaccines are also acceptable. Under current influenza epidemiological conditions, both offer largely comparable real‑world protection.

There is an update this year. On February 27, 2026, the World Health Organization released its recommended influenza‑vaccine composition for the Northern Hemisphere 2026‑2027 season. All three components (A(H1N1), A(H3N2), and B/Victoria) have been updated. Furthermore, as the B/Yamagata lineage has not been naturally detected globally since March 2020, it has been removed from the vaccine composition.

The national vaccination guidance, Chinese Technical Guidelines for Influenza Vaccination (2026‑2027), was issued by the Chinese Center for Disease Control and Prevention on September 2, 2026. It only recommends trivalent vaccines, in two formulations: one is the inactivated trivalent influenza vaccine (IIV3) for people aged 6 months and older; the other is the live‑attenuated trivalent influenza vaccine (LAIV3) for children aged 3‑17 years.

What about quadrivalent vaccines? Simply put, a trivalent vaccine contains two influenza A subtypes plus one influenza B lineage. A quadrivalent vaccine adds an extra influenza B lineage on that basis. Zhang Zhujiazi, Deputy Director of the Immunization Program Institute at Beijing Center for Disease Prevention and Control, has stated that under current influenza epidemic conditions, trivalent and quadrivalent vaccines deliver broadly equivalent real‑world protective effects. Do not assume quadrivalent vaccines are inherently superior. Get whichever is available. Quadrivalent vaccines have not been banned, nor are trivalent vaccines a “downgraded version”.

Question 2: When should we get vaccinated? Is it too late if we miss September‑October?

September‑October is generally recommended as the optimal vaccination window. The reasoning is straightforward: it usually takes 2‑4 weeks after vaccination for the body to develop protective antibody levels. Influenza season in China typically begins around November. Early vaccination ensures antibodies are ready in time.

Do not worry if you miss this window. Vaccination remains valid throughout the entire flu season; late vaccination is still far better than no vaccination. Once a full course is completed within one flu season, revaccination is unnecessary for that same season.

Question 3: Are my parents eligible for vaccination? Under which circumstances should vaccination be postponed?

Who can receive the vaccine: All persons aged 6 months and above without contraindications may be vaccinated. Eight priority groups are defined, including adults aged 60 years and older and people with chronic medical conditions — most elderly family members fall into these two categories.

True absolute contraindications are limited: first, known severe allergy to any vaccine component including excipients, formaldehyde, splitting agents or antibiotics; second, history of severe allergic reaction following previous influenza vaccination. Note that egg allergy is not an absolute contraindication. You may select vaccines whose package insert does not list egg allergy as a contraindication (per the 2025 edition of Chinese Pharmacopoeia, the ovalbumin upper limit per dose of split‑virus vaccine is 200 ng). Pregnant women likewise may receive vaccines that do not list pregnancy as a contraindication in their instructions.

Some conditions warrant postponement rather than outright prohibition: people with fever, acute illness, severe chronic disease, or acute exacerbation of chronic illness should wait until recovery or stable disease status before vaccination. Disclose these conditions truthfully to clinicians at the vaccination site. Final eligibility is subject to clinical assessment at the clinic and vaccine package inserts. You may also refer to Chinese Technical Guidelines for Influenza Vaccination (2025‑2026).

Question 4: Where to get vaccinated? How many doses are needed?

Vaccination sites are usually community health service centers, township health centers, or general hospitals. Local health authorities or centers for disease control publish lists of authorized vaccination clinics. Check their official websites, WeChat official accounts or mini‑programs to make nearby appointments.

Dose schedules depend on age: persons aged 9 years and older require one dose per year. For children 6 months to 8 years old receiving inactivated influenza vaccine for the first time, two doses are required with an interval of at least four weeks between doses.

One final reminder: influenza vaccines cannot guarantee complete protection against influenza. Nevertheless, they reduce the probability of infection and substantially lower risks of severe illness and death. Protection typically lasts 6‑8 months. Since influenza viruses mutate annually, annual revaccination is advisable.

Clarify these four points before taking your parents out for vaccination, and you will be well‑prepared.