Singapore has recently seen a pronounced rise in influenza cases. According to a Channel NewsAsia report, some clinics have observed as much as a tenfold increase in flu cases over the past few weeks amid weather fluctuations and lapsing preventive habits. Amid that backdrop, many people ask: If I’ve taken my COVID vaccinations, does that offer any protection against influenza?
In short: no, the COVID vaccination does not protect against influenza. But understanding the reasons behind that, and how both vaccines fit into a larger respiratory health strategy, is vital, especially now. Let’s explore why COVID vaccinations don’t prevent the flu, but still play an important role, and what you should do instead to protect yourself in this spike of influenza activity.
Why COVID Vaccination Doesn’t Prevent Influenza
Distinct Viruses, Distinct Vaccines
COVID-19 is caused by the SARS-CoV-2 virus, while influenza is caused by an entirely different family of viruses (influenza A and B). These viruses differ in their structure, behavior, and immune triggers. Because of that, the COVID vaccination is specifically engineered to stimulate immunity against SARS-CoV-2 and its variants; it does nothing to confer immunity to influenza viruses.
Immune Response Specificity
The immune system produces antibodies tailored to the antigens presented by a particular pathogen (or vaccine). The antibodies and T‑cells induced by a COVID vaccination do not cross-react meaningfully with influenza viral proteins. As a result, the protection is specific to COVID-19, not respiratory viruses in general.
No General “Respiratory Immunity”
Some might assume that boosting immunity via one vaccine would give broader protection, but that is not how immunology works. Each vaccine (COVID, influenza, pneumococcal, etc.) trains your immune system against specific threats. A COVID vaccination helps reduce your risk of contracting COVID-19 or having severe disease, but it doesn’t act as a universal respiratory shield.
So, Why Is COVID Vaccination Still Important During Flu Season?
Even though the COVID vaccination doesn’t protect against influenza, it remains crucial, especially in a season when respiratory infections are surging.
1. Reduces Burden on Healthcare
Simultaneous outbreaks of COVID-19 and influenza strain hospital systems. When more people are vaccinated against COVID-19 (via COVID-19 vaccination), fewer severe COVID cases occur, which conserves medical resources (beds, staff, ICU capacity) to manage other illnesses like influenza.
2. Lowers Risk of Dual Infection
Getting infected with both COVID-19 and flu at the same time can worsen outcomes. By maintaining protection through COVID immunization, you reduce one potential infection, which helps your body focus its defenses if exposed to influenza.
3. Minimises Confusion in Symptoms
COVID-19 and influenza share many symptoms: fever, cough, fatigue, sore throat. Widespread COVID vaccination reduces the chance that a respiratory illness is COVID, which may help healthcare providers triage and manage influenza cases more effectively.
4. Supports Overall Respiratory Health Strategy
In Singapore, health authorities recommend both COVID vaccines and annual flu vaccines for many groups. COVID vaccination is one pillar of a broader respiratory protection strategy that also includes influenza vaccination, masking, hand hygiene, and early medical consultation.
What’s Contributing to the Spike in Influenza Cases?
Understanding why influenza is surging now helps clarify why relying solely on COVID vaccination is insufficient.
Weather Fluctuations and Immune Vulnerability
Sudden changes in temperature, humidity, and increased rainfall may weaken the body’s natural defenses, making it easier for influenza viruses to spread. The CNA article noted that the spike is likely tied to weather-related vulnerability as well as declining mask use.
Reduced Preventive Measures
During the height of the COVID-19 pandemic, people were more diligent with masks, hand hygiene, and avoiding crowds. As those measures relax, influenza (which spreads via droplets and close contact) gains more opportunity. The CNA report highlighted that some of the current rise may stem from “weak precautionary practices.”
Vaccine Fatigue and Lower Flu Vaccination Uptake
Some may assume that being protected from COVID means overall better immunity, leading to complacency about the influenza vaccine. Also, fewer people are getting vaccinated against flu post-COVID due to vaccine fatigue or misunderstanding. This opens the door for influenza virus spread.
Singapore’s Travel and Viral Importation
Singapore is a global travel hub, so influenza strains from both hemispheres may arrive. The CNA article mentioned that Singapore is vulnerable to international flu strain importation given its connectivity and dense human traffic.
What Can You Do to Protect Against Influenza (Even with COVID Vaccination)?
Since COVID vaccination is not sufficient alone, here’s what you should do to strengthen your protection:
1. Get an Annual Flu Vaccine
This is the most direct protection against influenza. The flu vaccine targets the most likely circulating strains for the season. Unlike COVID vaccination, which focuses on SARS‑CoV‑2, the influenza vaccine is tailored to influenza A and B viruses. Many people who question efficacy do so because they misunderstand this distinction.
2. Maintain COVID and Flu Vaccinations Together
Keep your COVID vaccination up to date (boosters as recommended) and schedule your flu vaccination. The two do not interfere with each other in most cases, and together they protect you from two potentially serious respiratory illnesses.
3. Reinstate Precautionary Measures
With influenza activity high, return to masking in crowded or poorly ventilated spaces, especially if you’re immunocompromised. Also practice frequent handwashing, coughing etiquette, avoiding close contact with sick individuals, and staying home when symptomatic.
4. Monitor for Symptoms and Seek Care Early
If you develop fever, cough, body aches, or breathing difficulties, even if you’ve had your COVID vaccination, seek medical attention early. In some cases, antiviral treatments for influenza are most effective when given early.
5. Healthy Lifestyle and Immune Support
Ensure good nutrition, enough sleep, regular exercise, and stress management. A stronger immune system complements the protection conferred by both COVID vaccination and influenza vaccination.
Common Myths and Misconceptions
Here are two myths that often arise:
Myth: “Since I got the COVID vaccination, I won’t get any respiratory illnesses.”
Reality: No. As explained above, COVID vaccination protects exclusively against SARS‑CoV‑2—not influenza or other respiratory viruses.
Myth: “Getting both vaccines is unnecessary or risky.”
Reality: In most cases, receiving both the recommended COVID vaccination boosters and annual flu vaccine is safe and advised. They target different viruses and help reduce burden from both.
Conclusion
While the COVID vaccination remains a crucial tool in combating COVID-19, it does not offer protection against influenza. With the recent spike in flu cases in Singapore, driven by weather changes, reduced preventive behaviors, and waning flu vaccination coverage, relying on COVID vaccination alone is not enough to keep respiratory infections at bay.
To be well-protected, continue your COVID vaccination schedule, get your annual flu vaccine, and embrace preventive practices such as masking and hygiene. Together, these steps create a holistic defense against the season’s respiratory threats.
Stay Protected Against All Threats
At Keystone Clinic & Surgery, we provide expert, evidence-based preventive care. Whether you’re due for your COVID vaccination booster or an annual flu shot, or both, contact us so we can guide you through a safe, efficient, and informed vaccination experience.
References
Channelnewsasia.com. Some Singapore Clinics See Spike Flu Cases Amid Weather Changes, Weak Precautionary Practices. https://www.channelnewsasia.com/singapore/flu-cases-influenza-clinics-spike-weather-precautions-mask-vaccination-5337591
Straitstimes.com. Flu Cases in Singapore are on the Rise. Here’s How to Protect Yourself. https://www.straitstimes.com/singapore/health/time-to-vaccinate-against-influenza-heres-why-you-should
Time.com. As the Flu Surges in Asia, Could Getting Sick Year-Round Be the New Normal?. https://time.com/7324877/flu-asia-japan-india-singapore-influenza-strains-climate-epidemic-pandemic/