Have you taken your vaccine? In recent years, the term “vaccine” has become more familiar to our ears. With the importance of vaccination being emphasised, many have taken the initiative to take their vaccines. However, what exactly do vaccines do? And why are they so important?

Our body’s immune system

To understand the importance of vaccines, one must first learn about the body’s defense against infection. As germs invade our body, they attack and multiply. This process is known as an infection, which will lead to the development of diseases. In these scenarios, our immune system will deploy white blood cells to fight the infection. After the first infection, the immune system will remember what it learnt from the first infection, such that our body can fight off the infection more efficiently.

How do vaccines work?

Vaccines help to trigger an immune response within our body by imitating an infection. By doing so, it preps our immune system for future infections. This is also the reason why a person experiences minor symptoms such as fever, headaches, and fatigue after receiving their vaccines.

From the imitation infection, white blood cells such as B-lymphocytes and T-lymphocytes are deployed. Our vaccinated body will then contain a supply of these white blood cells.

B-lymphocytes aids in antibodies production, which are used to fight off infections, while T-lymphocytes destroy cells in our body that has been compromised by viruses, or has become cancerous. These white blood cells will retain the memory to fight off the actual disease in the future.

Why is it so important that we should be vaccinated?

The involvement of vaccines has proven to be essential in our lives. Currently, immunisation prevents 3.5 to 5 million deaths every year from a range of diseases1. Vaccines help generate a supply of B-lymphocytes and T-lymphocytes, which in turn helps our body to create antibodies to fight off infections and stay protected. There is an increased risk in complications that may arise in individuals if they are not vaccinated. Such complications may be chronic and incurable. Additionally, these unvaccinated individuals may also be more susceptible to vaccine-preventable diseases.

1Statistic source: www.who.int

Children Vaccination

What are the vaccines recommended by MOH?

There is a wide range of vaccines available for individuals to choose from. The National Adult Immunisation Schedule (NAIS) was developed to better guide individuals on which vaccines they should take. The NAIS aims to prevent infections and reduce the risk of complications, morbidity, and mortality. Here, we will highlight the most basic ones required for us to stay protected.

1. Influenza

Influenza, more commonly referred to as the flu, is caused by influenza viruses. Influenza differs from the common cold, as it can potentially cause severe illnesses and life-threatening complications. Complications varies for individuals of different age groups. The vaccine is recommended for all healthy adults, children, frequent travellers, and caregivers. It is particularly important for elderly who are over 65 years old, pregnant women, children under the age of six, and people with certain medical conditions like diabetes and asthma.

2. Pneumococcal conjugate (PCV13) and pneumococcal polysaccharide (PPSV23)

Pneumococcal disease includes the infection of the lungs, ear, brain, blood, and other serious infections. There are no serious side effects listed for either the childhood or adult versions of the vaccine, apart from an extremely rare risk of a severe allergic reaction known as anaphylaxis. This vaccine is recommended for all adults over the age of 65.

3. Tetanus, reduced diphtheria, and acellular pertussis (Tdap)

Tdap vaccine helps to prevent tetanus, diphtheria, and pertussis. Pertussis and diphtheria spreads from person to person. Tetanus enters the body through cuts or wounds. Tetanus leads to painful stiffening of muscles. Diphtheria can lead to difficulty in breathing, paralysis, heart failure, or even death. Pertussis causes uncontrollable and violent coughing, which may lead to other complications. Tdap is especially important for pregnant women and is usually given between 16 and 34 weeks of gestation.

4. Human papillomavirus (HPV2 or HPV4)

Human papillomavirus (HPV) strains are the cause of several types of cancer, particularly cervical cancer. It is also one of the most common sexually transmitted infections. The HPV vaccine helps to protect against the strains of HPV. In Singapore, the Ministry of Health recommends sexually active women aged 30 years and above to get screened for HPV every five years.

5. Hepatitis B

Hepatitis B spreads when body fluids from an infected person enters the body of someone who is not affected. It is caused by the hepatitis B virus (HBV), which can be prevented by getting vaccinated. HBV affects each individual differently, with age being a key factor to determine whether the infection is a short-term illness, or develop into a chronic illness. All adults aged 18 to 59 should receive the vaccine if they have not previously done so as a child. Any adult who requests for it may get vaccinated, provided a blood test has been done to show than vaccination is required. All adults 18 years and older should get screened at least once in their lifetime.

6. Measles, mumps, and rubella (MMR)

The MMR vaccine helps to prevent against mumps, measles, and rubella. Mumps can lead to other complications such as deafness and swelling of the brain and even death. Measles can lead to complications such as seizures, ear infections, and pneumonia. Rubella can lead to complications such as arthritis, or birth defects and miscarriage for women who gets rubella while pregnant. Most individuals who are vaccinated with MMR will be protected for life.

7. Varicella

The Varicella-Zoster Virus (VZV) causes a highly infectious disease known as chickenpox. Chickenpox spreads primarily via airborne transmission, but can also spread via droplets or direct contact by an infected person. The varicella vaccine helps to prevent chickenpox.

These recommended vaccines are available at most Raffles Medical clinics. There are subsidies available for eligible Singaporeans:

This article was written by: Dr Derek Li, Senior Family Physician, Raffles Medical