As the COVID-19 pandemic continues to evolve, booster shots have become an essential part of public health strategy. While the initial vaccine series has provided a significant level of protection against severe illness, hospitalisation, and death, studies have shown that immunity can wane over time.
Booster shots are designed to restore and prolong this immunity, especially in the face of new and emerging variants. Understanding the purpose and benefits of booster doses, and knowing who should receive them, is key to keeping communities safe and healthy.
What Are COVID Booster Shots?
A booster shot is an additional dose of a vaccine given after the original protection has started to decline. With COVID vaccination, booster shots are formulated to enhance the body’s immune response and provide extended protection against the virus. This is especially important for respiratory viruses like SARS-CoV-2, which are constantly mutating.
COVID-19 boosters may be similar to the original vaccine or updated to target specific variants, such as Omicron. In many cases, these updated boosters—known as bivalent vaccines—offer broader protection by addressing multiple virus strains simultaneously.
Boosters are recommended at specific intervals after the last dose, depending on a person’s age, health status, and the type of vaccine they initially received.
Why Immunity Wanes Over Time
Like other vaccines, the immune response generated by the original COVID-19 vaccine series can diminish gradually. This decline doesn’t mean the vaccines aren’t effective; rather, it reflects the natural decrease in antibody levels and other immune defenses. As immunity fades, the risk of breakthrough infections can increase, particularly among vulnerable populations.
Booster doses help “remind” the immune system how to fight the virus effectively. They restore waning immunity and help the body respond more quickly and robustly if exposed again. This can significantly reduce the severity of illness, shorten the duration of symptoms, and lower the chances of transmitting the virus to others.
Who Should Get a COVID Booster Shot?
Health authorities such as the World Health Organization (WHO) and national agencies like Singapore’s Ministry of Health recommend booster shots for various groups based on risk levels.
High-priority groups include:
- Elderly individuals, especially those aged 60 and above
- People with chronic medical conditions such as diabetes, heart disease, or weakened immune systems
- Frontline healthcare workers and caregivers
- Pregnant women, to protect both mother and unborn child
- Residents of long-term care facilities, who face higher exposure and complication risks
For the general adult population, booster shots are recommended to maintain protection, particularly when new variants are circulating. In Singapore, eligible individuals are advised to receive booster doses at least five months after their last COVID-19 vaccination, and yearly booster shots may be encouraged for certain groups as the virus continues to circulate globally.
The Role of Boosters in Variant Protection
One of the most compelling reasons for booster shots is their ability to address evolving variants. The virus that causes COVID-19 changes over time, and some variants may partially escape the immune protection offered by the original vaccine formulation. Boosters, particularly those updated for newer strains, help fill this gap by increasing antibody levels and enhancing the breadth of the immune response.
In clinical studies, people who received booster doses had better protection against symptomatic infection caused by Omicron and its subvariants compared to those who had only completed the primary vaccination series. This means that while breakthrough infections may still occur, they are more likely to be mild and less likely to result in severe outcomes.
Benefits Beyond the Individual
The advantages of booster shots extend beyond personal health. When more people in the community are protected, the overall spread of the virus slows. This is particularly important in protecting those who cannot receive vaccines due to medical reasons or those who are more vulnerable despite being vaccinated.
Widespread COVID vaccination, including booster shots, helps reduce the burden on the healthcare system by preventing hospitalisations and intensive care admissions. It also supports the safe continuation of economic and social activities, such as schooling, travel, and public events.
COVID Vaccination Myths and Misconceptions
Despite the proven benefits, misinformation continues to circulate around COVID vaccination and booster doses. One common myth is that boosters are only necessary if the initial vaccines “failed.” In reality, the original vaccines did not fail—they prevented millions of deaths and severe cases. Boosters simply ensure that protection is sustained over time.
Another misconception is that frequent boosting can “overload” the immune system. Scientific evidence shows the opposite: well-spaced boosters strengthen the immune response and improve memory cells without overwhelming the body. Vaccines, including boosters, are rigorously tested for safety and efficacy before being recommended to the public.
What to Expect After a Booster Shot
Side effects from COVID booster shots are generally similar to those experienced with the initial doses. Common reactions include arm soreness, fatigue, mild fever, and muscle aches—signs that the body is building protection. These symptoms usually resolve within a couple of days.
Serious side effects are extremely rare. If you have a history of allergic reactions or concerns about pre-existing health conditions, speak to a healthcare provider before your booster appointment. In most cases, even individuals with complex medical histories can safely receive boosters under proper medical supervision.
When and Where to Get Your Booster
The timing of your booster depends on your last dose and current health guidelines. In Singapore, residents can refer to MOH’s eligibility checker or consult their family physician to determine when their next dose is due. Many clinics, including general practitioners and public health centres, offer booster appointments for eligible individuals.
Keystone Clinic & Surgery provides up-to-date COVID-19 vaccines, including bivalent boosters, in a convenient and safe environment. With professional guidance and friendly staff, your vaccination experience can be smooth and reassuring.
Staying Prepared for the Future
The fight against COVID-19 is far from over, but we are far better equipped now than in the early days of the pandemic. Booster shots play a pivotal role in ensuring that immunity remains strong and adaptable. As public health guidance continues to evolve with the emergence of new data, staying informed and proactive about your vaccinations is a smart and responsible step.
COVID-19 may become endemic, but with consistent and up-to-date COVID vaccination, we can reduce its impact significantly. Making booster shots a regular part of your healthcare routine helps protect yourself, your loved ones, and the broader community.
Protect Yourself and Your Loved Ones
At Keystone Clinic & Surgery, we are committed to helping you stay protected with timely and effective COVID vaccination services. Our team offers updated booster shots, personalised guidance based on your health profile, and a seamless vaccination experience.
Whether you’re due for your next dose or seeking advice about eligibility, we’re here to support your health journey every step of the way. Book your COVID booster appointment with us and stay one step ahead in protecting your well-being.
References
Cdc.gov. Benefits of Getting Vaccinated. https://www.cdc.gov/covid/vaccines/benefits.html#:~:text=Getting%20vaccinated%20against%20COVID%2D19,%E2%80%932025%20COVID%2D19%20vaccine.
Osfhealthcare.org. What is a Booster Shot and Why Do I Need It?. https://www.osfhealthcare.org/blog/covid-19-booster-shots/
Med.stanford.edu. Model Estimates Who Benefits Most From Frequent COVID-19 Boosters. https://med.stanford.edu/news/all-news/2024/03/covid-booster.html