The Importance of Immunisations

Category: Newborns

MH speaks to the experts on the importance of immunisations.


Vaccination is considered one of the most important advancements in the history of medicine. Non-vaccination could allow diseases to spread. Many arguments can be made for and against vaccination, and the decision to vaccinate can be complex. However, parents today are aware that infectious diseases can spread rapidly, and people who are not vaccinated put their own health and public health at risk.


What is Immunisation?

Immunisation is a safe and effective way of protecting people from harmful infections. After receiving a vaccine, the body’s natural immune system learns to recognise those infections, so that if the person encounters the germ in the community, he or she can fight off the infection, explains Dr Guadalupe Viegelmann, senior resident, Dept of Neonatal & Developmental Medicine, SGH.


How Immunisations Work?

Vaccines contain small amounts of either live but weakened viruses, killed viruses or bacteria, or a modified form of a toxin from bacteria. When a person receives a vaccine, explains Dr Viegelmann, their body responds as if fighting off the infection, although they don’t develop symptoms of the disease itself. In the future, if the person comes into contact with the disease from someone else in the community, their immune system quickly remembers how to defend itself against the disease. The immunised person will not develop any symptoms, or only very mild symptoms of the disease.


Getting Your Children Immunised

Infections in children can start right from birth. Though there are some antibodies that do cross the placenta to provide some protection, this is usually inadequate and most of the important ones for infants and young children are very low in mothers. Furthermore, the immune system in young children does not work as well as in older children and adults, because it is still immature. Therefore, more doses of vaccines are often needed. Children also get many immunisations because new vaccines against serious infections continue to be developed. These are all needed as once infected, it can be very serious leading to morbidity and mortality, says Dr Ong Eng Keow, consultant paediatrician, International Child & Adolescent Clinic, Mount Alvernia Hospital.



Children should be immunised to prevent them from

getting serious infectious diseases that can kill or cause long-term

disabilities or health problems.



As younger children are particularly vulnerable to many potentially dangerous infections due to them having a more immature immune system as compared to an adult, these children need more vaccinations.

Immunisation prevents children from becoming ill with unpleasant and serious infectious diseases, which have a risk of complications and long-term side effects, explains Dr Ong. Some of these may even lead to death. Until these diseases are eradicated, every child that is not immunised is at risk of complications if they catch the actual infectious disease itself. Immunisation is practising the axiom of Prevention is better than Cure. Immunisation is the safest way of protecting children from serious infections which they may encounter in the community. Children who are immunised against these diseases are unlikely to fall ill, or if they do, have milder symptoms than unimmunised children.


How long do these immunisations last?

Some vaccinations provide lifelong immunity or protection against diseases while others offer shorter term protection and multiple booster doses are required. The duration of protection from a vaccination depends on the disease that is being protected, the vaccine itself and the person who has been vaccinated, explains Dr Wendy Sinnathamby, specialist in paediatrics and consultant, Raffles Children’s Centre.

For example, Hepatitis B immunisations may provide lifelong immunity once the course of vaccines has been completed. Other immunisations can last for years but will require booster shots later on, such as Diptheria, Tetanus, and Pertussis. The flu vaccine is given annually, to protect against the prevalent strain of virus for that year.


What are some reasons to delay immunisation?

There are a few reasons to delay immunisation. Vaccines should generally be delayed if the child has

moderate to severe infections. If a person is sick with a high fever over 38°C, immunisation should be postponed until the person is recovering. Other reasons to delay vaccines include being immunocompromised or being on a prolonged course of steroids, says Dr Sinnathamby. There are very few medical reasons to delay immunisation. Check with your doctor if you’re unsure.


Getting that Jab

Immunisation is a simple, safe and effective way of protecting a child from diseases that can cause serious illness and sometimes death, emphasises Dr Ong.



If most children are vaccinated, this indirectly protects people

who are still susceptible to the disease as they are less likely to

come into contact with someone who is carrying the pathogens.

This concept is known as herd immunity.



Herd immunity can protect those who are too young to be vaccinated or cannot be vaccinated because of medical conditions (e.g. receiving chemotherapy) and those who do not respond adequately to immunisation. The more people who vaccinate their children, the greater our ability to control serious vaccine-preventable diseases.


Is immunisation still necessary in this day and age?

Prevention is always better than cure. Immunisations are an absolute must to protect the children who receive them, as well as those around them who are unable to receive vaccinations for medical reasons, from preventable infectious diseases, explains Dr Viegelmann. As global travel increases, children may be more exposed to these diseases; hence it is important for them to be protected.

Immunisation is the safest and most effective way of protecting against vaccine-preventable diseases.  After immunisation, a person is far less likely to catch the disease if there are cases in the community. If enough people in the community are immunised, the infection can no longer be spread from person to person. In this way, smallpox was eradicated in 1980, and only a few isolated cases of polio remain in the developing world.

The medical community generally agrees that vaccines have proven to be the most effective way to prevent the spread of many devastating illnesses that once plagued society. Education may help people learn how to maintain the quality of their improved environment, eg, improved living conditions reduce exposure to pathogens. Vaccination provides protection against common, devastating diseases that spread between people. 

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