Preventing diseases in children - The role of complete vaccination

When a large proportion of children in the community are fully vaccinated, both vaccinated children and those who cannot yet be vaccinated are protected through herd immunity. In Vietnam, the Expanded Programme on Immunization (EPI) has been implemented since 1981 and remains a core pillar in protecting children's health nationwide [2].

1. Why Do Children Need Complete Vaccination?

1.1. A Child's Immune System is Immature

Young children, especially newborns and those under 2 years of age, have incomplete immune systems. In the first months of life, infants are only partially protected by passive antibodies passed from the mother through the placenta and breast milk – but these antibody levels gradually decrease and disappear after a few months [3]. At that point, children are nearly "defenseless" against a series of dangerous pathogens such as tuberculosis, hepatitis B, measles, diphtheria, pertussis, tetanus, polio, and pneumonia... Vaccines act as a "teacher," helping a child's immature immune system learn to recognize and safely destroy pathogens without causing the actual disease [3].

1.2. Vaccines Prevent Millions of Deaths Each Year

According to the World Health Organization (WHO), vaccination prevents 3.5 to 5 million deaths globally each year from vaccine-preventable diseases [2]. Over the past 25 years in Vietnam alone, vaccines have protected 6.7 million children and prevented 42,000 deaths from dangerous infectious diseases such as diphtheria, pertussis, tetanus, and polio [1]. These are not just numbers – behind them are millions of families that have been spared the pain of losing a child to entirely preventable diseases.

1.3. Unvaccinated Children Face Exponentially Higher Risks of Disease

If children are not fully vaccinated, their risk of contracting diseases and experiencing severe complications increases significantly. Diseases such as diphtheria can cause airway obstruction leading to death; pertussis causes prolonged, severe coughing spells lasting weeks, which is especially dangerous for infants under 6 months old; neonatal tetanus causes muscle stiffness and a very high mortality rate; and hepatitis B can lead to cirrhosis and liver cancer later in life [2][6]. Thanks to vaccines, Vietnam has eradicated polio and eliminated neonatal tetanus – critical medical achievements that could easily return if vaccination coverage declines [2].

1.4. Timely Vaccination Protects Children During the "Golden Window"

Vaccination schedules are designed based on scientific research to protect children at the exact time they are most vulnerable to infectious diseases [5]. For example:

- The hepatitis B dose within the first 24 hours after birth helps prevent mother-to-child transmission – if delayed, its effectiveness drops markedly.

- The 5-in-1 or 6-in-1 doses administered at 2–4 months of age protect children when maternal antibody levels have waned [6].

1.5. Complete Vaccination Helps Save Healthcare Costs

The cost of a vaccination is much lower than the cost of treatment when a child falls ill. According to the WHO, vaccination is one of the most cost-effective medical interventions – every dollar spent on vaccines can save up to 16 dollars in direct and indirect healthcare costs [3]. This not only reduces the financial burden on families but also relieves pressure on the healthcare system.

1.6. Vaccination is a Responsibility to the Community

When a high proportion of children in a community are fully vaccinated (typically 90–95% depending on the disease), the spread of pathogens is halted. This is particularly crucial to protect children who cannot receive vaccines due to health reasons (severe allergies, immunodeficiencies, undergoing cancer treatment, etc.) [1]. UNICEF emphasizes that immunization protects not only individuals but is also a responsibility shared by the entire community – every vaccinated child is a step closer to a healthy and safe generation of Vietnamese children [1].

2. Key Vaccination Milestones for Children

U.S. Centers for Disease Control and Prevention (CDC) recommends that children be vaccinated according to a specific schedule starting right from birth [4]. Vaccination schedules are designed to protect children at the time they are most vulnerable to infectious diseases [5].

In Vietnam, the Ministry of Health issued the Expanded Programme on Immunization Plan for the 2026–2028 period (Decision No. 278/QĐ-BYT dated August 29, 2025), continuing to maintain and expand vaccines within the program, including vaccines against hepatitis B, tuberculosis, diphtheria, pertussis, tetanus, polio, measles, rubella, Hib pneumonia/meningitis, Japanese encephalitis, and several others [6].

Key vaccination milestones for children (referenced from Vietnam's EPI Program):

Note: Vaccination schedules may vary by locality. Parents should bring their children to local commune/ward health stations or immunization centers for specific guidance.

3. Important Notes for Parents

3.1. Before Vaccination

• Ensure the child is well-fed and dressed in comfortable, loose-fitting clothing that is easy to remove

• Bring the vaccination record book and previous immunization slips

• Inform the doctor if the child has a fever, an acute illness, or a history of allergy to any vaccine component

• Do not arbitrarily give the child fever-reducing medication before vaccination without a doctor's prescription [4]

3.2. During and After Vaccination

• Keep the child calm and soothe them during the injection

• Stay at the healthcare facility for at least 30 minutes post-vaccination to monitor for any reactions

• Monitor the child at home during the first 24-48 hours after vaccination

• Cool compresses can be applied to the injection site if the child experiences swelling or pain

• Encourage the child to drink plenty of fluids; do not avoid bathing or wind exposure [4]

When to Seek Immediate Medical Attention After Vaccination

Take your child to a healthcare facility immediately if any of the following signs appear within 48 hours post-vaccination [4]:

• High fever exceeding 39°C that does not respond to antipyretic medication

• Prolonged crying, refusal to feed, or lethargy

• Generalized rash, breathing difficulties, or cyanosis

• Extensive swelling and redness spreading around the injection site

• Seizures or abnormal neurological signs

4. Conclusion

Full and timely vaccination is the strongest "steel shield" protecting children against dangerous infectious diseases. Parents are encouraged to proactively bring their children to healthcare facilities for vaccination following the guidelines of the Ministry of Health and the Expanded Programme on Immunization. Every vaccination today is a solid step forward for the future health of our children.

5. References

• [1] UNICEF Vietnam. Immunization.

  https://www.unicef.org/vietnam/immunization. Accessed: 27/05/2026.

• [2] WHO. Vaccines and Immunization in Viet Nam.

  https://www.who.int/vietnam/health-topics/vaccines-and-immunization. Accessed: 27/05/2026.

• [3] WHO. Essential Programme on Immunization. 

  https://www.who.int/teams/immunization-vaccines-and-biologicals/essential-programme-on-immunization. Accessed: 27/05/2026.

• [4] CDC. Vaccines for Your Children. 

  https://www.cdc.gov/vaccines-children/index.html. Accessed: 27/05/2026.

• [5] CDC. Vaccine Schedules for Children and Teens. 

  https://www.cdc.gov/vaccines-children/schedules/index.html. Accessed: 27/05/2026.

• [6] Ministry of Health of Vietnam. 3-Year Expanded Programme on Immunization Plan (2026–2028), issued with Decision No. 278/QĐ-BYT dated August 29, 2025. Accessed: 27/05/2026.

The information above is for reference purposes only and is not intended as medical advice. Please contact your doctor for detailed medical consultation.