15/05/2023 11:08 AM
Opinions on topical issues from thought leaders, columnists and editors.
By :
Dr Lee Mei Ling

Immunisation is an important preventive measure to protect an individual from diseases. The most common method of increasing immunisation is through vaccination as it is the easiest, safest and most effective way to prevent diseases, especially among children who need additional protection from contracting illnesses.

Vaccinating children is very important because it protects and reduces the risk of them contracting serious or fatal diseases.

A vaccine is a dead, or weakened version, or part of the germ that causes the disease in question. When children are vaccinated, their immune system will form antibodies to protect them from contracting the disease.

The antibodies formed in children’s bodies will help their bodies to recognise certain germs or bacteria so that it can fight the disease in the future.

When children are given one dose or an additional dose, they will be protected for years. This proves that vaccination is the most effective, safe and wise way to produce an immune response in the body, without causing any illness.

National Immunisation Programme

There are 12 preventable diseases listed under the National Immunisation Programme (NIP) including diphtheria, haemophilus influenza type B, hepatitis B, human papillomavirus, Japanese encephalitis, measles, mumps, pertussis, poliomyelitis, rubella, tetanus and tuberculosis.

NIP was introduced in the early 1950s and was designed based on the World Health Organisation (WHO) Expanded Programme on Immunisation (EPI).

Based on the NIP Immunisation Schedule, vaccines are provided free of charge in all government clinics and hospitals throughout the country to enable children to receive injections as scheduled.

Apart from the Japanese encephalitis vaccine, which is only compulsory in Sarawak, every child must receive their vaccines according to schedule unless it is due to any underlying illness or medical condition which requires further discussion with the doctor.

The immune response to antigens and immunisation can be divided into two categories which are the primary response or secondary response.

The primary immune response to an antigen takes between 10 to 14 days to allow the body to produce antibodies. For the secondary immune response against the same pathogen, the memory cells generated before will react faster to produce antibodies to prevent infection, which is to kill the pathogen before it causes an individual to get sick.

Not all vaccines confer lifelong immunity as it depends on the type of vaccine.

For example, vaccines for measles and hepatitis B will give immunity for life while those for tetanus or influenza will last for many years but require regular shots (boosters) to ensure continued protection. Therefore, parents need to keep records of their children's vaccinations to ensure they are given injections or boosters when necessary.

Low risk of causing harm

Vaccines can cause side effects to the recipients such as common fever, discomfort and pain at the injection site, but usually these side effects are minimal.

The risk of causing harm is low. If the child experiences a side effect or reaction to the vaccine that is detrimental to their health, then the additional dose will not be given.

However, there may be failure in immunisation due to breakdown of the delivery system to provide potent vaccines to the individuals in need and also failure of immune response due to inadequacies of the vaccines or other factors inherent in the child.

In addition, a weak immune system or immunosuppression caused by several factors including stress, malnutrition, concurrent infections or an immature immune system may also cause vaccination failure.

There is also the issue of children missing out on the necessary vaccinations (Missed Opportunity Vaccinations). This is because the parents do not check their children’s vaccine status in addition to the lack of knowledge about contraindications of vaccination.

If children are not vaccinated, they will be exposed to the risk of contracting diseases that could be preventable through vaccines.

Benefits far more than side effects

Vaccination has sparked some debate but there is no convincing evidence to show that it is detrimental to its recipients.

There may be parents who question the effectiveness of vaccines, but they should understand that vaccines or immunisations are important to protect their children for the long term.

The benefits are far more than the side effects that may occur. Parents are also advised to listen to the views or opinions of relevant medical experts before making any decision.


Dr Lee Mei Ling is Sunway Medical Centre, Sunway City’s Consultant Paediatrician and Neonatologist.

The views expressed in this article are those of the author(s) and do not reflect the official policy or position of Bernama.

(The views expressed in this article are those of the author(s) and do not reflect the official policy or position of BERNAMA)