Since the onset of the COVID-19 pandemic, vaccination has been one of the most powerful tools in reducing the spread of the virus and protecting people from severe illness. Over the years, vaccines have been updated, booster shots introduced, and public health recommendations refined. Today, a pressing question remains: are booster vaccinations still effective?
In Singapore, where the government has consistently prioritised public health through vaccination campaigns, many people are evaluating whether booster shots continue to offer protection. This article explores the role of booster vaccinations, their effectiveness, and why they remain an essential part of the COVID vaccination strategy.
Understanding Booster Vaccinations
A booster vaccination is an additional dose given after the initial primary series of a vaccine. Its purpose is to “boost” the body’s immune response, which may wane over time.
COVID-19 vaccines, like many others, do not offer lifetime immunity. This is not unusual — vaccines against influenza, tetanus, and hepatitis also require repeat doses or boosters to maintain effectiveness.
When it comes to COVID-19, booster doses play two key roles:
- Restoring immunity: Immunity tends to decline several months after the initial vaccination series. Boosters refresh the body’s defence, ensuring continued protection.
- Improving protection against variants: Viruses mutate, and COVID-19 has produced several variants of concern. Boosters are often updated to match these evolving strains.
How Effective Are Booster Vaccinations?
Restoring Protection Against Severe Illness
Clinical data from Singapore and around the world has shown that COVID vaccination with boosters significantly reduces the risk of severe illness, hospitalisation, and death. This is especially important for older adults and those with underlying health conditions.
While protection against infection may decline over time, the ability of boosters to prevent serious outcomes remains strong. This means that even if a vaccinated individual contracts COVID-19, they are far less likely to experience severe symptoms.
Strengthening Immunity Against Variants
One of the biggest challenges in the pandemic has been the emergence of new variants such as Delta, Omicron, and their subvariants. Booster vaccinations are often reformulated to provide better protection against these strains.
For example, bivalent boosters introduced in recent years were designed to target both the original COVID-19 strain and newer variants, enhancing overall coverage.
Evidence From Singapore
Singapore’s Ministry of Health (MOH) has consistently monitored vaccine performance. Studies show that residents who received their booster shots had stronger and more durable protection compared to those who only completed their primary series. This evidence underpins the country’s continued emphasis on booster uptake.
Why Immunity Wanes Over Time
It is natural for vaccine-induced immunity to decline over months or years. This is due to the way the immune system functions.
- Initial peak, gradual decline: After vaccination, antibody levels rise sharply, but they slowly decrease over time.
- Memory response: While antibody levels may drop, the immune system retains “memory cells” that can respond more effectively if the virus is encountered again.
- Booster effect: Receiving a booster dose stimulates these memory cells, causing a renewed antibody surge and strengthening long-term protection.
This is why boosters are not a sign of vaccine failure but rather a normal and expected part of maintaining immunity.
Who Should Prioritise Booster Vaccinations?
While booster doses are beneficial for all eligible individuals, certain groups should prioritise them due to higher risk.
- Older adults (60 years and above): Age naturally weakens the immune system, making seniors more vulnerable.
- People with chronic medical conditions such as diabetes, heart disease, or weakened immune systems.
- Healthcare workers and frontline staff who face regular exposure to the virus.
- Pregnant women who need protection for both themselves and their unborn child.
In Singapore, MOH provides clear guidelines on COVID booster jab eligibility, often recommending that higher-risk groups receive updated boosters more frequently.
Common Misconceptions About Booster Vaccinations
“If I’ve had COVID-19, I don’t need a booster.”
Natural infection does provide some immunity, but it may not be long-lasting or strong enough against variants. A COVID vaccination with a booster offers more consistent and reliable protection.
“Boosters are not effective because people still get infected.”
Boosters may not always prevent infection entirely, especially with highly transmissible variants. However, their main purpose is to prevent severe illness, hospitalisation, and death — and they continue to do this effectively.
“Young and healthy people don’t need boosters.”
While younger adults may face lower risks, boosters still help reduce the spread of the virus, protect vulnerable populations, and decrease the chances of long-term complications like Long COVID.
Global and Local Perspectives
Globally, health authorities like the World Health Organization (WHO) and the U.S. Centers for Disease Control and Prevention (CDC) have recommended booster doses as part of COVID-19 vaccination programs.
In Singapore, boosters remain a central part of public health strategy. The government offers free or subsidised booster vaccinations and strongly encourages eligible residents to stay up to date. This policy reflects an evidence-based approach that balances individual health with broader community protection.
The Future of Booster Vaccinations
Transitioning to Endemic COVID-19
Singapore has moved into a stage where COVID-19 is treated as an endemic disease — something managed over the long term rather than eradicated. In this context, booster vaccinations will likely remain a recurring part of healthcare, similar to annual flu shots.
Development of Updated Vaccines
Pharmaceutical companies continue to refine vaccines to target emerging variants more effectively. In the future, booster shots may be combined with seasonal flu vaccines for convenience.
Focus on Personal Responsibility
As policies evolve, individual responsibility becomes more important. Staying up to date with COVID vaccination is not just about personal protection but also about protecting loved ones and reducing strain on healthcare systems.
Taking Care of Your Health in Singapore
The success of Singapore’s COVID vaccination campaigns lies not only in government initiatives but also in the proactive role of residents. Keeping up with booster recommendations ensures that individuals contribute to the collective resilience of the nation. Healthcare providers across the country, including private clinics, offer updated boosters, consultations, and guidance on vaccination schedules.
Call to Action for Keystone Clinic & Surgery
At Keystone Clinic & Surgery, we are committed to supporting Singapore’s fight against COVID-19 by providing accessible and professional vaccination services. Our team ensures that every patient receives the latest guidance on booster shots, tailored to their age, health status, and risk profile.
If it has been some time since your last shot, now is the right time to check your eligibility for a booster. Protect yourself, your family, and the wider community. Book your COVID vaccination booster at Keystone Clinic & Surgery today and take the next step in safeguarding your health.
References
Cdc.gov. Staying Up To Date with COVID-19 Vaccines. https://www.cdc.gov/covid/vaccines/stay-up-to-date.html
Osfhealthcare.org. What is a Booster Shot and Why Do I Need It?. https://www.osfhealthcare.org/blog/covid-19-booster-shots
Pmc.ncbi.nlm.nih.gov. mRNA-Based COVID-19 Vaccines Dose: Benefits, Risks, and Coverage. https://pmc.ncbi.nlm.nih.gov/articles/PMC9335425/