Do you really need a vaccine booster? An expert explains why they still matter

Vaccination is not a guarantee that one will maintain immunity throughout life. In fact, some vaccines require more than one application at various points in time. For those vaccines, a booster will be necessary. The booster is the dose of vaccine given after finishing the primary course of vaccination with the objective of achieving protection against the infection again.

What is the mission of a booster?

Upon vaccination, the immune system learns about the pathogen and begins developing an immune response. Depending on the vaccine applied, the primary course might guarantee a relatively good level of immunity, while the subsequent shots will help with the enhancement or preservation. The booster is a chance for the immune system to reconnect with the pathogen and increase the amount of antibodies.

What causes immunity to weaken?

The immunity given by vaccines will change over time. Antibody levels in the body can fall naturally, despite the fact that the body keeps its immune memory. In some cases, a drop in circulating antibodies means that it might be advantageous to get vaccinated again. The duration of immunity can differ from one vaccine to another. Some vaccines provide immunity for a long time after the primary series of vaccination, while others require vaccines more often.

Boosters are not only for kids

There is a belief that boosters are required mostly for children, but this is not completely true. Certain vaccines are recommended later in life as well. Adults need to receive booster doses depending on their vaccination history, age, occupation, travel plans, pregnancy status, health conditions, or exposure risk. This means that some vaccines that contain tetanus must be administered later. Additionally, certain vaccines might be administered to a group of people who face a higher risk in certain situations.

Why are boosters important for older adults?

The immune system changes as we get older, a process called immunosenescence. Older adults sometimes have weaker immune systems to fight off diseases, leading to increased chances of having complications. Therefore, when people get older, vaccinations and booster doses become even more important, since they reduce the chances of infection, so that severe disease, hospitalisation, and complications are avoided.

What is the effect of a delayed booster on a vaccination record?

As the interval between the last vaccination and the booster increases, the vaccination record does not become invalid. In many situations, the vaccine will be given when the patient can receive it. However, the strategy that should be employed in such cases depends on the type of vaccine being used, along with the age and previous vaccination history of the patient. People should use caution in taking any extra doses without help from a doctor.

Are booster doses needed always?

Not necessarily. It does not mean that every vaccine requires a booster shot every few years. For some vaccines, protection is long and persistent after the entire required course is completed. However, certain vaccines might require subsequent doses to maintain protection as immunity decreases over time, or due to the need for additional protection caused by epidemiologic and disease-related issues. Booster recommendations may also change as new data becomes available. Booster recommendations undergo periodic reviews by public health authorities based on data on vaccine effectiveness, disease patterns, and safety.

Why do you need to keep the vaccination record?

After receiving their childhood vaccines, most people tend to forget about keeping track of their immunization records. While they might recall childhood vaccinations, they might not remember when they received their last booster. Keeping vaccination records can enable medical professionals to establish whether people need additional doses. It is especially important before travelling internationally, becoming pregnant, entering a particular profession, going to medical facilities, or if someone has a health condition.

Booster doses constitute part of a bigger scheme for ensuring protection throughout one's life. Booster doses do not mean that the primary vaccine “did not work,” but merely point out the functioning of the immune system and infectious diseases over time. The key thing is that people should stick to the provided vaccination schedule and not think that protection lasts forever. If you don’t know if you or your child needs a booster shot, check the vaccination records and contact your doctor. Keeping vaccination information updated not only helps with individual protection against infections but also helps in protecting the community, as the risk of receiving a vaccine-preventable disease is lower.

The author is a Consultant - Pediatric Gastroenterology and Hepatology at Madhukar Rainbow Children’s Hospital.

The opinions expressed in this article are those of the author and do not purport to reflect the opinions or views of THE WEEK.