Childhood Vaccine Guide: How to Choose the Right One

Primary vaccines (Primary vaccines) are the “basic vaccines” that every child must receive according to the immunization plan of the Ministry of Public Health and the recommendations of the Pediatric Infectious Diseases Society of Thailand. They should be given according to the specified schedule, such as the Diphtheria–Tetanus–Pertussis vaccine (DTaP/Tdap) Polio vaccine (IPV/OPV) Measles–Mumps–Rubella vaccine (MMR) to prevent severe diseases that may cause disability or death.

For “optional vaccines” (Optional vaccines) and “non-mandatory vaccines” (Non-mandatory vaccines) are practically the same type of vaccines but may be called differently because they are outside the basic vaccines mandated by the Ministry of Public Health for all children. Therefore, they are not compulsory, such as the pneumococcal infection vaccine (PCV/IPD) influenza vaccine (Influenza vaccine) varicella vaccine (Varicella vaccine) hepatitis A vaccine (Hepatitis A vaccine) and HPV vaccine (HPV vaccine) which parents can choose to give their children to build immunity that primary vaccines do not cover.

Choosing supplemental or optional vaccines for your child

The decision to vaccinate your child with supplemental or optional vaccines should be made carefully and consider many factors. Regular consultation with a vaccine doctor will help plan or adjust the vaccination schedule to suit the health and needs of each child. Factors to consider include:

• Risk of disease: Consider how likely the child is to be exposed to various diseases, such as children attending daycare centers, living in high-risk environments, having immunodeficiency, or having a family history of immune disorders.
• Child’s health and immunity history: Consider any history of vaccine or drug allergies, chronic diseases, immunodeficiency, or underlying conditions.
• Necessity based on circumstances: For example, traveling to areas with disease outbreaks or living in high-risk communities to adjust the vaccination plan accordingly.
• Cost-effectiveness and medical necessity: Some supplemental vaccines are expensive, so consider the necessity and benefits along with the doctor’s advice.
• Regularly follow the vaccination schedule and medical recommendations: Schedules and recommendations may change based on disease situations, outbreaks, or new research to ensure your child receives complete and age-appropriate vaccines.

Comparison table of primary vaccines and supplemental/optional vaccines

Primary Vaccines

Supplemental Vaccines/Optional Vaccines

How do combined vaccines, brand switching, and injection techniques affect vaccine efficacy?

Considerations for combined vaccines, brand switching, and injection techniques are as follows:

• Combined vaccines in one injection combine several vaccines to be given in a single shot but protect against multiple diseases simultaneously, such as the DTP-HB-Hib combined vaccine which protects against diphtheria, tetanus, pertussis, hepatitis B, and Hib in one injection. Although combined vaccines may slightly increase the dose of some vaccines, they do not cause severe side effects and are highly safe. Doctors will select approved combined vaccines suitable for each child’s health individually. Combined vaccines reduce the number of injections, causing less pain, reducing stress for both children and parents, fewer hospital visits, and lower risk of incomplete or delayed vaccination.
• Switching vaccine brands is possible but should always be consulted with a doctor and not done unnecessarily because each brand may have different components, adjuvants, or manufacturing techniques. If multiple vaccines are given on the same day, they should be injected at different sites, such as left arm, right arm, or different body parts, at least 2-2.5 centimeters apart to reduce pain and irritation and make it easier to observe adverse reactions.

• Injection technique involves choosing the injection angle to deliver the vaccine into the appropriate tissue layer for optimal vaccine effect and reduced side effects, as follows:

• • Intradermal injection is used for vaccines that require local immune stimulation, such as the BCG vaccine, which uses a small amount of vaccine and a shallow angle to place the vaccine in the dermis.
  • Subcutaneous injection is suitable for vaccines that require slow and continuous absorption, mostly live vaccines such as the MMR vaccine.
  • Intramuscular injection is the most common method for most vaccines because muscles have blood vessels and tissues that allow rapid and effective absorption. It is mostly used for inactivated vaccines such as the combined DTP vaccine.

When should you urgently see a doctor after vaccination?

After vaccination, the body may respond with some symptoms, most of which are normal reactions indicating that the body is building immunity. However, parents should closely observe symptoms and distinguish between normal reactions and those requiring urgent medical attention as follows:

Common and normal symptoms

• Pain, swelling, redness, and warmth at the injection site
• Low-grade fever (37.5-38.5 °C)
• Slight drowsiness or fatigue
• Mild itchy rash at the injection site
• For BCG vaccine, a small pus-filled bump may appear within the first 2-3 weeks and will gradually disappear on its own

Symptoms requiring immediate medical attention

• Widespread hives all over the body
• Severe vomiting or diarrhea
• Difficulty breathing or abnormal breathing
• Low blood pressure or shock
• Chest pain or palpitations
• Swollen or inflamed lymph nodes after BCG vaccination

Recommendations for parents

• Closely monitor the child’s symptoms for 48 hours after vaccination
• If fever exceeds 39 °C, sponge the child and give antipyretics as advised by the doctor
• Most symptoms will resolve within 1-3 days
• If symptoms do not improve or abnormalities occur, see a doctor immediately

Special considerations for vaccination

Parents should know that proper and appropriate vaccination is important for safety and effective immunity. There are special cases to consider to maximize benefits and reduce risks as follows:

• Children with immunodeficiency, such as those on immunosuppressive drugs, with immune disorders, or undergoing cancer treatment, should not receive live vaccines (Live-attenuated vaccines) such as MMR or varicella vaccines due to high risk of vaccine-derived infection.
• Children with a history of vaccine or vaccine component allergies, such as egg allergy (in older influenza vaccines) or yeast allergy, should inform the doctor before vaccination to consider alternatives or appropriate advice.
• Children who are acutely ill or have a high fever should postpone vaccination until symptoms resolve to ensure that fever or complications are not caused by the vaccine and to ensure the child’s body is ready for vaccination.
• Children with chronic diseases such as heart, kidney, liver, or uncontrolled neurological diseases should consult their primary doctor to assess risks and plan safe and appropriate vaccination.
• Children who have received excessive doses of the same vaccine, although not severely harmful, should avoid unnecessary repeated doses to prevent confusion in vaccination tracking. Careful and correct vaccination planning helps avoid this problem.
• Premature infants can receive vaccines according to their actual age but should be specially monitored and evaluated by a doctor to ensure readiness for each vaccine.

Phyathai Phaholyothin Hospital offers vaccination services for your child

Your child’s health is the most important thing for parents. Phyathai Phaholyothin Hospital offers more than just vaccination services by providing comprehensive preventive health care focusing on both safety and maximum effectiveness, including:

• Personalized vaccination planning: Our pediatric team is ready to consult and plan vaccinations suitable for the child’s age, health, and risk individually, including primary and optional or supplemental vaccines for comprehensive and appropriate protection.

• A wide range of vaccines, including combined vaccines for multiple diseases in one injection to reduce the number of injections, and disease-specific vaccines for targeted prevention.
• Close monitoring after vaccination for maximum safety: We have a special observation area after vaccination and provide advice on caring for your child and how to observe symptoms at home.
• Convenient services: The Child and Adolescent Health Center is open daily from 08:00-20:00 to allow parents to bring their children at convenient times.

Let Phyathai Phaholyothin Hospital be part of building strong immunity so your child grows up healthy at every stage.

FAQ: Frequently Asked Questions about Child Vaccines

Q: Should I choose combined vaccines or separate vaccines?

A: Generally, doctors recommend combined vaccines because they reduce the number of injections, pain, chances of forgetting or missing vaccines, and are convenient for follow-up. In some cases, such as children with allergy history or health limitations, doctors may consider separate vaccines for the child’s safety.

Q: If my child misses a vaccine dose, do we have to start over?

A: It depends on the type of vaccine. It is recommended to consult a doctor. Most vaccines do not require starting over and can continue from the missed dose because the immune system still remembers the vaccines previously received. Doctors will help adjust the schedule appropriately to ensure full protection.

Q: If vaccinated, will my child never get that disease again?

A: Not always. Vaccines reduce the risk of illness and, if the disease occurs, make symptoms less severe. However, they do not provide lifelong protection for all diseases. Therefore, some vaccines require booster doses periodically, such as the tetanus vaccine recommended every 10 years because immunity gradually decreases over time.