Childhood Immunisation/ Vaccination

Childhood immunisation refers to the immunisation or vaccination of your child against vaccine-preventable diseases such as hepatitis B, diphtheria, and measles. Building immunity early in life can protect your children from serious illnesses that may be life-threatening complications or even death.

At Phoenix Medical Group, we are dedicated to your children having the best start to life, and timely vaccination ensures the health and safety of your children.

How do vaccines work?

Vaccines help the body to build immunity against diseases caused by an infection. When a person is vaccinated, the vaccine particles are detected by the immune cells such as dendritic cells to induce an immune response. Surface proteins on the pathogen, called antigens, are registered by these antigen-presenting cells as harmful signals. Other immune cells such as T-cells and B-cells become activated when detecting these harmful signals. B-cells produce antibodies, which are proteins specific to the antigen that neutralise the antibodies or mark them for elimination by other immune cells [1]. 

In the future, if the person is infected with the same pathogen, the immune cells are able to recognise the antigen and elicit a quicker response to eliminate or neutralise the infectious agent, hence reducing the risk of a serious infection.

Types of vaccinations

When designing vaccines, scientists take into consideration how the immune cells will recognise the pathogenic antigens. Common types of vaccines are [1]:

• Live-attenuated vaccines – Live-attenuated vaccines use weakened live viruses, these are also the earliest type of vaccines [2]. Common vaccines that are live-attenuated include measles, mumps, and rubella (MMR), and smallpox.
  
• Inactivated vaccines – Inactivated vaccines involve inactivated or dead viruses that cannot replicate. This type of vaccine can be considered safe even for immunocompromised individuals [1].
  
• Subunit vaccines – Subunit vaccines use only part of the virus, such as the antigens only, or the capsid of the virus.
  
• Toxoid vaccines – Toxoid vaccines use the toxins of bacteria instead of the organism itself. Common types of toxoid vaccines are diphtheria vaccine and tetanus vaccine.
  
• Viral vector vaccines – Viral vector vaccines use a different type of virus, called a vector, to carry the genetic information of the target virus. The vector virus will then produce the antigens of the target virus, which will be detected by the body’s immune system. Viral vector vaccines are considered a recent technology, an example of viral vector vaccines is COVID-19 vaccine [3].
  
• Nucleic acid vaccines – Similar to viral vector vaccines, nucleic acid vaccines use the genetic material of the virus. Nucleic acid vaccines can be DNA or mRNA, which is then coded into the antigen particle in the person’s body. Nucleic acid vaccines are relatively new, many scientists are actively studying it for any possible long term effects [1].

What vaccinations does my child need?

Children are more vulnerable to infectious diseases due to their underdeveloped immune system that are not as effective in protecting them from environmental exposure. Every country has a childhood immunisation programme to protect them against common vaccine-preventable diseases such as polio, measles, diphtheria, and tetanus.

The Ministry of Health (MOH) of Singapore has set a National Childhood Immunisation Schedule for recommended vaccines for babies and children. It is a list or schedule of the vaccines your child needs as they grow. The Ministry of Health lists the recommended vaccination schedule for babies to children of age 17. It is highly recommended to adhere to the schedule closely and avoid missing vaccine doses to provide full protection.

The National Childhood Immunisation Schedule may be downloaded from the MOH website here.

Why do I need to vaccinate my child?

Vaccination is a form of protection for your child, as well as for others who may be vulnerable and cannot get vaccinated. 

• Individual protection – Vaccination protects your child by training their immune system via exposure to pathogens that can be life threatening or cause serious complications, such as sepsis or meningitis. Infections of these pathogens may elicit mild or no symptoms because your child’s immune system will be able to recognise and fight the infection early.
  
• Herd immunity – Herd immunity is described as immunity of a significant portion of a population against a disease [4]. When many individuals are immune to a disease, it makes it harder for the disease to spread. This in turn protects vulnerable people from getting infected. Examples of vulnerable individuals include:
  • Elderly people with a weakened immune system
  • Babies too young to get vaccinated
  • People with immune deficiencies 

What are the side effects of vaccination?

Side effects of vaccination often occur due to the body’s immune response working to fight the ‘infection’. These immunological responses often manifest in inflammatory responses such as fever and pain. Common side effects of vaccination in children include [5, 6]:

• Local reactions
  • Pain at site of injection
  • Redness around area of injection
  • Swelling 

• Mild reactions
  • Fever 
  • Headache
  • Tiredness or fatigue
  • Muscle pain
  • Loss of appetite
  • Vomiting 

• Severe reactions
  • Severe headaches
  • High fever
  • Fainting 

Most vaccine injections tend to elicit mild reactions which typically resolve in a few days. In the case that your child’s condition is not improving or becomes worse, seek immediate medical attention.

When is it not suitable to vaccinate my child?

Most babies and children are fit to receive vaccines following the immunisation schedule set by the Ministry of Health. However, there are certain situations where your child may not be suited for a vaccination, which include:

• When your child is recovering from an illness
• If your child has had a previous reaction to certain vaccines
• If your child is immunocompromised or taking medication that suppresses the immune system

In these cases, it is advisable to consult your family doctor or paediatrician before seeking other options for immunisation. 

Are my child’s vaccinations insurance/MediSave claimable in Singapore?

For Singaporeans and PR, MediSave can be used to pay for your child’s vaccination. However, certain claims are only applicable to specific criteria such as the age group of your child when receiving the vaccine. Childhood vaccinations under the National Childhood Immunisation schedule, is fully subsidised for Singaporeans.  

What to expect when I come for my child’s vaccination appointment?

The common procedure for a vaccination appointment for your child is as follows:

• Consultation – Our doctors and pediatrician will talk you through what types of vaccines your child needs at their age. You can ask your doctor regarding any questions you may have regarding the vaccine, any side effects, or what to do in case of an allergic reaction.
  
• Immunisation – The doctor will then deliver the vaccination shot to your child. It is common that children may be scared and react negatively, you can calm and soothe your child or distract them from the doctor giving the injection. It is important to be patient with them and reward good behaviour.
  
• Monitoring – Once at home, monitor your child’s condition for any adverse reactions. Mild reactions such as local pain or swelling should subside within a day or two. Severe reactions such as high fevers may require hospitalisation, contact your doctor or get to the nearest emergency services in these cases.

Our doctors at Phoenix Medical Group will also update your child’s immunisation record in the National Immunisation Registry, which you can check online to stay updated.

We also carry other types of vaccines like influenza vaccines and Japanese Encephalitis vaccines. Schedule a consultation with our doctors to discuss your child’s needs or book a vaccination appointment to kick start your child’s immunisation journey.

<Download links from Phoenix Medical website>

Children vaccination brochure (Internal)

Children vaccination brochure (External)

Frequently Asked Questions

What happens if I miss a dose?

It is important to adhere to the immunisation schedule. However, unforeseen circumstances are not avoidable, if the appointment is missed, contact your doctor as soon as possible to reschedule at the earliest convenience. Completing the doses for immunisation provides effective protection against infections.

Do vaccines really cause autism?

No, the study from 1998, which discusses the link between MMR vaccines and autism has been retracted and discredited after numerous studies conducted found no evidence between MMR vaccines and autism risk. This is a good example of misinformation in public health. Due to the widespread misinformation, vaccination rates against MMR dropped, leading to outbreaks of measles in many parts of the world [1, 7].

Can my child attend school without being vaccinated?

In Singapore, under the Infectious Disease Act, measles and diphtheria vaccines are mandatory for a child to start primary school. These diseases are contagious and can be fatal for children whose immune systems are still developing.

References

1. Montero DA, Vidal RM, Velasco J, Carreño LJ, Torres JP, Benachi O MA, Tovar-Rosero YY, Oñate AA, O'Ryan M. Two centuries of vaccination: historical and conceptual approach and future perspectives. Front Public Health. 2024 Jan 9;11:1326154. doi: 10.3389/fpubh.2023.1326154. PMID: 38264254; PMCID: PMC10803505.
2. Iwasaki A, Omer SB. Why and How Vaccines Work. Cell. 2020 Oct 15;183(2):290-295. doi: 10.1016/j.cell.2020.09.040. PMID: 33064982; PMCID: PMC7560117.
3. Deng S, Liang H, Chen P, Li Y, Li Z, Fan S, Wu K, Li X, Chen W, Qin Y, Yi L, Chen J. Viral Vector Vaccine Development and Application during the COVID-19 Pandemic. Microorganisms. 2022 Jul 18;10(7):1450. doi: 10.3390/microorganisms10071450. PMID: 35889169; PMCID: PMC9317404.
4. Desai AN, Majumder MS. What Is Herd Immunity? JAMA. 2020 Nov 24;324(20):2113. doi: 10.1001/jama.2020.20895. PMID: 33074287.
5. Khatereh A, Koruosh G, Alireza T, Daryuosh J, Parastoo B. Adverse Events Following Immunizations in Infants Under 1 Year of Age in Lorestan Province, Western Iran. J Prev Med Public Health. 2023 Mar;56(2):172-179. doi: 10.3961/jpmph.22.540. Epub 2023 Mar 14. PMID: 37055359; PMCID: PMC10111094.
6. Alamer E, Alhazmi A, Qasir NA, Alamer R, Areeshi H, Gohal G, Qadri M, Hashem AM, Algaissi A. Side Effects of COVID-19 Pfizer-BioNTech mRNA Vaccine in Children Aged 12-18 Years in Saudi Arabia. Vaccines (Basel). 2021 Nov 9;9(11):1297. doi: 10.3390/vaccines9111297. PMID: 34835228; PMCID: PMC8621258.
7. DeStefano F, Shimabukuro TT. The MMR Vaccine and Autism. Annu Rev Virol. 2019 Sep 29;6(1):585-600. doi: 10.1146/annurev-virology-092818-015515. Epub 2019 Apr 15. PMID: 30986133; PMCID: PMC6768751.