Flu Season: Is It Too Late to Get Vaccinated?

As the flu season sweeps across Asia, you may wonder whether it's too late to get vaccinated. The short answer is: no, it’s not too late. Health experts emphasize that flu vaccination remains beneficial throughout the season, as influenza viruses continue to circulate for several months, sometimes into late spring. Dr. Sze-Man Wong, from Marina Medical in Hong Kong, breaks down everything for you.

Why Flu Vaccination Matters

Influenza, commonly known as the flu, is a contagious respiratory illness caused by influenza viruses. It can lead to mild to severe symptoms, and in some cases, serious complications. These complications might happen to any part of the body: pneumonia in the lungs, myocarditis in the heart or encephalitis in the brain. Hospitalization is required for these conditions as sequelae and death might happen—especially for high-risk groups like young children, pregnant women, the elderly, and individuals with underlying medical conditions.

“Seasonal influenza is usually self-limiting with recovery from a few days to 2 weeks. Patients complain of fever, cough, sore throat, runny nose and muscle pain. Flu viruses spread through droplets from infected people when they sneeze, cough or simply talk. The incubation is around 2 to 4 days.“ says Dr. Wong.

Vaccination is the most effective way to prevent flu infection, reduce symptom severity, and lower the risk of flu-related complications. The flu shot is designed to stimulate the immune system to develop protective antibodies that help fight the virus if exposed later.

What Do Flu Vaccines Do During Flu Season?

Flu vaccines work by:

• Training the Immune System: The vaccine introduces inactive or weakened virus components, helping the body recognize and fight the real virus if encountered.
• Reducing Infection Risk: The vaccine lowers the likelihood of contracting the flu, minimizing the spread within communities.
• Lessening Symptom Severity: Even if vaccinated individuals contract the flu, symptoms tend to be milder and shorter in duration compared to those who are unvaccinated.
• Protecting Vulnerable Populations: Widespread vaccination helps protect high-risk individuals through herd immunity.

Dr. Sze-Man Wong explains: “Despite the proven benefits of the flu vaccine, there is still a chance of getting flu after vaccination but the infection will likely last shorter and be milder. The effectiveness of the flu vaccine can vary from season to season as it depends on the “match” between the vaccine and the virus in the circulation.”

According to the World Health Organization (WHO), the recommended flu vaccine strains for the 2024–2025 season have been updated to provide maximum protection against circulating strains, ensuring effectiveness throughout the flu season.

Is It Too Late to Get a Flu Shot?

No, flu vaccination remains beneficial even later in the season. The Centers for Disease Control and Prevention (CDC) advises getting vaccinated as long as flu viruses are circulating, which in many parts of Asia can extend until April or May. Since it takes about two weeks for immunity to develop after vaccination, getting the shot in January or February can still provide significant protection.

According to Dr. Wong, “Winter influenza in Hong Kong usually starts in January. In 2024, it started in mid-January and ended in late July, lasting 28 weeks. It lasted longer due to several changes of the circulating virus strains. It is still worth receiving the vaccine in February.”

Who Should Get Vaccinated Now?

While flu vaccination is recommended for everyone over six months old, it’s especially important for:

• Seniors (persons aged 50 years old or above in Hong Kong are eligible to receive the vaccination)
• Pregnant women
• Children under five
• Individuals with weakened immune systems or chronic illnesses (e.g. diabetes, asthma, heart disease)
• Healthcare workers and caregivers

Flu Vaccines Available in Asia

Different flu vaccines are available across Asia, including:

1. Quadrivalent Influenza Vaccine (QIV): Covers four flu strains (two A and two B types), providing broader protection. The injection is an inactivated vaccine, it does not contain live influenza virus.
2. Trivalent Influenza Vaccine (TIV): Protects against three strains, commonly available in public health programs. Nasal spray influenza vaccines are trivalent and contain a live attenuated virus.
3. Cell-Based and Recombinant Vaccines: More advanced vaccines offering improved protection without the use of egg-based manufacturing, ideal for those with allergies.

Vaccines are available through hospitals, private clinics, and government health programs in countries such as China, Hong Kong, and Singapore. Some regions offer free or subsidized vaccines for high-risk individuals under national immunization programs.

Dr. Wong explains that “some people may have some concerns about the flu vaccine and have postponed it due to fears of side effects. I understand their worries but the flu vaccine does really help. Thanks to it, admission to hospital can be avoided and we see a reduction in hospitalisations by about 50%. Absenteeism decreases as well. The benefits outweigh the inconvenience of the flu vaccine.”

Health Insurance Coverage for Flu Vaccines

When considering flu vaccination, it's important to check whether your health insurance plan covers it. Coverage varies depending on the insurer and type of policy.

1. Public Health Insurance:

   • In some countries, government health programs provide free or subsidized flu shots for at-risk groups.
   • Coverage may vary depending on residency status and eligibility.

2. Private Health Insurance:

   • Many comprehensive plans include coverage for preventive care, including flu vaccinations.
   • Some plans may reimburse vaccination costs if administered at approved clinics.

3. Employer-Sponsored Plans:

   • Some companies offer flu vaccination programs as part of employee health benefits.
   • Employees should check if their corporate health insurance covers annual flu shots.

4. Out-of-Pocket Costs:

   • If not covered by insurance, flu vaccines are relatively affordable in most countries, with costs typically ranging between $20 to $50 USD depending on the type and location of vaccination.

How to Check Your Flu Vaccine Coverage

If you're unsure whether your health insurance covers flu shots, consider the following steps:

• Contact your insurance provider or your HR to ask about preventive care coverage.
• Check your policy details online or in your plan documents for flu vaccine coverage information.

Take Action Now: Protect Yourself and Others

Even if flu season has already started, getting vaccinated now can still help reduce your chances of getting sick and spreading the virus to others. In addition to vaccination, practicing good hygiene—such as frequent handwashing, wearing masks in crowded places, and avoiding close contact with sick individuals—can further lower your risk of infection.

This article was independently written by Alea and is not sponsored. It is informative only and not intended to be a substitute for professional advice and should never be relied upon for specific advice.