Respond Detect Report Investigate Adverse Events Following Immunization Dr S.M.Zahraei Center for Disease Control Ministry of Health and Medical Education

AEFI is a medical incident that takes place after an immunization, causes concern, and is believed to be caused by immunization u Vaccine reaction è caused by vaccine’s inherent properties u Programme error è caused by error in vaccine preparation, handling or administration

u Coincidental è happens after immunization but not caused by it a chance association u Injection reaction è anxiety or pain of injection not vaccine u Unknown è cause can not be determined

Cluster of AEFI >=2 cases of the same adverse event following immunizations related in time, geography or in the vaccine administered –Why is it important to monitor for clustering?

Potential Objectives For AEFI Surveillance System Detect, correct, and prevent programme errors Identify problems with vaccine lots or brand Prevent false blame from coincidental events Maintain confidence by properly responding to parent/community concerns while increasing awareness (public and professional) about vaccine risks

Generate new hypotheses about vaccine reactions that are specific to the population Estimate rates of occurrence on AEFI in the local population, compared with trial and international data (particularly for new vaccines being introduced)

Programme Errors Non-sterile injection –infection Incorrect preparation –abscess (inadequate shaking) –drug effect (use of drug instead of vaccine/diluent)

Injection in wrong site –local reaction/abscess (wrong tissue level) –nerve damage Vaccine frozen –local reaction Contraindication ignored –avoidable severe reaction

Serious Events Anaphylactoid reaction (acute hypersensitivity reaction) Anaphylaxis Persistent (more than 3 hours) inconsolable screaming Hypotonic hyporesponsive episode Seizures, including febrile seizures (6-12 days for measles/MMR; 0-2 days for DTP) Encephalopathy (6-12 days for measles/MMR; 0-2 days for DTP)

Serious Events (cont…) Acute flaccid paralysis –(4-30 days for OPV recipient; 4-75 days for contact) Brachial neuritis –(2-28 days after tetanus containing vaccine) Thrombocytopaenia –(15-35 days after measles/MMR) Disseminated BCG infection Osteitis/osteomyelitis

THANK YOU FOR YOUR ATTENTION

DETECTING AND REPORTING AEFIs

Which Events To Report? Death, hospitalization, or other severe/unusual events Toxic shock syndrome Severe local reaction Sepsis Injection site abscess (bacterial/sterile) BCG lymphadenitis AEFIs causing concern or suspicion of vaccine involvement

Which Reports To Investigate? Investigate if possible programme error serious event of unexplained cause above expected rate (not just numbers) potential damage to the immunization programme Certain events (toxic shock syndrome, sepsis, abscess,and BCG lymphadenitis) are likely to arise from programme errors and must always be investigated

Contraindications True contraindications are rare Current serious febrile illness –delay vaccine administration History of severe AEFI after previous dose Evolving neurological disease –avoid whole cell pertussis vaccine –(e.g. uncontrolled epilepsy) Type 1 hypersensitivity to egg - avoid yellow fever & influenza but can use vaccines made in chick fibroblasts Symptomatic HIV –avoid BCG and yellow fever

Contraindications Anaphylactic reaction to neomicin, streptomycin or polymyxin B IPV Immunodeficiency, or immunodeficient household contact* OPV Encephalopathy within 7 days of administration DTP Anaphylactic reaction to vaccine or vaccine constituent Severe febrile illness All vaccines ContraindicationVaccine * Risk benefit assessment when administered to HIV positive individuals Adopted from Plotkin pg 66-67

Contraindications Anaphylactic reaction to common baker’s yeast Hepatitis B Anaphylactic reaction to egg, immunodeficiency Yellow fever NoneHib Anaphylaxis, pregnancy, immunodeficiency* MMR ContraindicationVaccine * Risk benefit assessment when administered to HIV-positive individuals Adopted from Plotkin pg 66-67