Vaccinations are important for public health. They prevent the spread of contagious diseases, and in many cases, can be life-saving.

Today, thanks to advances in medical science, vaccinations provide protection against more diseases than before. In addition to the more commonly known vaccines such as those for influenza, hepatitis B and chickenpox, vaccines for other conditions like shingles (zoster), dengue, and the human papilloma virus (HPV) have been introduced over the years. The HPV vaccine, for instance, reduces the risk of cervical cancer.

Debunking myths

However, a percentage of the population may not be getting adequate vaccination protection due to poorer health literacy and misconceptions.

“Some misconceptions include the belief that vaccines have long-term serious side effects, which will weaken the immune system. Many tend to believe that natural immunity gained from an actual infection is better, but this is not true,” said Dr Ng Chung Wai Mark, Clinical Lead for Infection Prevention and Infectious Disease Workgroup, SingHealth Polyclinics, and Senior Consultant, Outram Polyclinic.

​<<Vaccines do not weaken the immune system, but instead prepare it to fight against infections, said Dr Ng Chung Wai Mark.>>

Vaccines are generally safe and well tolerated. They do not weaken the immune system, but instead prepare it to fight against infections. They provide one’s body with immunity — similar to natural immunity that one gets from an actual infection — without the person having to risk complications related to natural infections.

In most cases, vaccination involves an injection, which triggers the immune system to produce antibodies that fight against a particular infection, thereby providing immunity against it. For example, the vaccine injection may contain proteins from the surface of germs, or even dead or weakened germs that are incapable of causing illness in healthy persons. Some vaccines, such as messenger RNA (mRNA) vaccines, may not contain any part of the germ, but molecules that make up a set of instructions to instruct cells in the body to make harmless proteins to trigger an immune response.

Vaccines for hepatitis B, measles, mumps and rubella (MMR), and chickenpox provide long-term immunity, while others, such as the diphtheria and pertussis vaccines, require boosters every 10 years.

Vaccines to get

There are currently two vaccinations made mandatory by Singapore law. These are for measles and diphtheria, usually completed when the toddler is around 18 months old during the National Childhood Immunisation Schedule (NCIS) exercise.

Other vaccines that are routinely given as part of NCIS include those that fight hepatitis B, chickenpox, pneumococcal, influenza, and human papillomavirus.

“Singapore’s vaccination programme has improved over the years. The NAIS (National Adult Immunisation Schedule) was established in November 2017 to provide guidance on vaccinations for individuals aged 18 years or older as a means to avert vaccinepreventable diseases,” said Dr Ng.

For example, influenza and Tdap vaccines (a combined vaccine against tetanus, diphtheria and pertussis) are recommended for pregnant women, while influenza and pneumococcal vaccines are recommended for the elderly.

“Increasing the uptake of vaccines will not only protect our community, but also build up herd immunity,” said Dr Ng. “When a large percentage of the population is vaccinated against a particular disease, the likelihood of a disease spreading from one person to another is lowered. This will prevent the possibility of an outbreak, and protect individuals who are not able to receive the vaccine for various reasons, such as medical conditions or allergies.”

Many vaccines are subsidised in Singapore. From 1 November 2020, vaccines such as chickenpox and the 6-in-1 (combined diphtheria, acellular pertussis, tetanus, Haemophilus influenza type B and hepatitis B) have been added to the list of subsidised vaccinations for Singaporeans.

“With the help of vaccination subsidies from the government, there has been an increased uptake of recommended vaccines,” said Dr Ng.

Before travelling

For travellers, the recommended vaccines depend on the destination.

If there is risk of food and waterborne infections, especially for travellers who intend to consume food from street vendors and visit areas where food and water hygiene may be of concern, doctors may recommend vaccinations against infections such as cholera, typhoid and hepatitis A. If travellers plan to stay in areas near large bodies of water for prolonged periods of more than a month, and where mosquito breeding may occur, such as paddy fields, the Japanese Encephalitis (JE) vaccine, which protects against JE (a viral brain infection spread by mosquitoes) is recommended, said Dr Ng.

Dr Limin Wijaya, Senior Consultant, Department of Infectious Diseases, Singapore General Hospital, advises travellers to get a proper medical consultation to find out the type of vaccinations needed — based on their health conditions, past vaccinations, and holiday destination.

It is also important to plan and get vaccinated early as certain doses require a few weeks to become effective.