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Surveillance of Adverse Events Following Immunization

Vaccine and Immunization

Immunization is a process of giving the vaccine to individuals in order to enhance the immune system against infectious diseases. The vaccine is an antigen (virus or bacteria) which have been weakened or dead and has been injected into the body or given through the mouth or nose. Next, the body will respond by producing antibodies and memory cells. These antibodies and memory cells will remember and attack the antigen if the infection occurs.

The immunization program is the best way to protect individuals from infectious diseases that can be prevented by vaccination, particularly those with weaker immune systems such as infants and children. Immunization is a proven tool for controlling and eliminating life-threatening infectious diseases and is estimated to avert between 2 and 3 million deaths each year.

National Immunization Program (NIP)

The Malaysian National Immunization Program (NIP) was introduced in the early 1950s and it has been given free to the children for their protection against major childhood diseases. The immunization program offers protection against major childhood diseases that can be prevented with vaccines including diphtheria, tetanus, pertussis, Haemophilus influenzae type b, hepatitis B, measles, mumps, rubella, tuberculosis, polio and some diseases caused by the human papillomavirus. This program is available at all government clinics across the country.

Parents are responsible for ensuring that their children are protected from dangerous infectious diseases that can be prevented with a vaccine. Below is the national immunization schedule to ensure your child receives the vaccination at the right time.

Adverse Events Following Immunization (AEFIs)

Adverse events following immunization (AEFIs) is any untoward medical occurrence which follows immunization and which does not necessarily have a causal relationship with the usage of the vaccine.The adverse event may be any unfavourable or unintended sign, abnormal laboratory finding, symptom or disease. Reported adverse events can either be true adverse events which is really a result of the vaccine or immunization process, or coincidental events that are not due to the vaccine or immunization process but are temporally associated with immunization.

In 2012, the World Health Organization (WHO) revised the existing classification relevant to cause-specific categorization of AEFIs and a new categorization has been introduced. They are vaccine product-related reaction, vaccine quality defect-related reaction. immunization error-related reaction, immunization anxiety-related reaction and coincidental event.

Vaccine Reactions

There are two types of vaccine reactions which are common, minor reactions or rare, more serious reactions. Most vaccine reactions are mild and resolve on its own quickly such as injection site reactions and fever. More serious reactions like anaphylaxis are very rare and, in general, do not result in long-term problems.

Management Of AEFI

  1. Observation after vaccination

    Recipients of vaccines should remain under observation of health personnel for a short interval to ensure that they do not experience an immediate adverse event. It is recommended that recipients remain in the vicinity of the place of vaccination for at least 15 minutes. Severe anaphylactic reactions usually have a rapid onset; most life-threatening adverse events begin within 10 minutes of vaccination.

    The most serious immediate AEFI is anaphylaxis. However, in adults and older children, the most common immediate adverse event is a vasovagal episode (fainting), either immediately or soon after vaccination. Anyone who complains of giddiness or light-headedness before or after vaccination should be advised to lie down until free of symptoms to prevent serious consequences due to fainting. Most faints following vaccination occur within 5 minutes, and 98% occur within 30 minutes. Thus, adults should be warned of the risk of driving or operating machinery for at least 30 minutes after vaccination.

  2. Managing injection site reactions

    It is common to have local reactions at the injection site example redness, itching, swelling or burning for 1 to 2 days after vaccination. Paracetamol might be needed to ease the discomfort. Sometimes a small, hard lump may persist for some weeks or months. This should not be of concern and requires no treatment.

  3. Managing fever after immunization

    Paracetamol may be required if the infant or child has a high fever following vaccination. The dose of paracetamol is 15 mg/kg of paracetamol liquid, up to a maximum daily dose of 75 mg/kg per day. Tepid sponging could be helpful in reducing the high body temperature and give extra fluids to drink. Do not overdress an infant if hot.

Vaccine Safety Surveillance

National Centre of Adverse Drug Reactions (ADR) Monitoring, National Pharmaceutical Control Bureau (NPCB) is responsible to monitor the safety of medicines and vaccines that are registered in Malaysia. NPCB is responsible for collecting all reporting adverse events related pharmaceutical products including vaccines. All reported adverse events will be documented and serious cases following vaccination will be investigated promptly to identify the cause of the adverse events. NPCB will make further investigation in terms of product quality and regulatory action will be taken based on the results of the investigation. Types of regulatory action that can be taken are the suspension of the product registration, product recall or cancellation of the product registration.

ADR reporting system has been introduced in Malaysia to enable health providers to participate in monitoring the safety of medicines and vaccines by reporting the adverse events. Ministry of Health Malaysia (MOH) has organized trainings to the health professionals on the importance of reporting of AEFIs as described in the Guidelines for the Pharmacovigilance of Vaccines. Ongoing training will be conducted more actively to increase awareness among health care providers to report AEFI and importance of disseminating the information to parents/guardians.

Currently, the AEFI reporting system has been extended to the public whereby the parents/guardians of children who experience any adverse events can report to us by themselves.

Reporting of AEFIs in Malaysia

The public/parents/guardians of children who experienced any AEFIs should report immediately. Printed form (Appendix A) can be obtained from the hospital, clinic or community pharmacy and sent by mail to:

Pusat Pemonitoran Kesan Advers Ubat Kebangsaan,
Biro Pengawalan Farmaseutikal Kebangsaan,
Peti Surat 319, Pejabat Pos Jalan Sultan,
46730 Petaling Jaya
Fax to 03-79567151.

The public can return the form to the facility where the injection was given and it will be forwarded to the NPCB. Additionally, the form can also be downloaded from NPCB website or submitted online at www.bpfk.gov.my

The Benefits of Reporting the AEFIs

The purpose of having a system where health professionals, publics, parents and anyone who has been immunized can report any AEFIs is to ensure that any potential safety signals are detected, assessed and acted on immediately if necessary.

The National Centre of ADR Monitoring will continuously monitors all adverse drug reactions, including serious AEFIs and will make an analysis and evaluation to ensure that all medicines including vaccines which are used/market in Malaysia are safe of good quality and efficacious. If there are situations where the risk of using the drugs /vaccines outweigh the benefit to patients/consumers, necessary regulatory action will be taken.

Patients and public are encouraged to report any adverse drug reaction or AEFIs as these data will be useful in detecting any possible safety signals related to the use of drugs/vaccines.


  1. Guidelines for immunization programme managers on surveillance of adverse events following immunization, Second Edition
  2. http://www.immunise4life.my/
  3. http://www.who.int/topics/immunization/en/
  4. Immunization Safety Surveillance
Last Reviewed : 24 June 2015
Writer/Translator : Nurulhuda bt. Hamdan
Accreditor : Rokiah bt. Ishak