Events after vaccination (ESAVI) and how they are reported !
- Topic
An ESAVI is any health problem that appears after vaccination. The vaccine is not always the cause, so it is reported and investigated.
Updated 2026-11-01
What it is
ESAVI is the Spanish acronym for an event supposedly attributable to vaccination or immunization; Colombia also uses EAPV (adverse event following vaccination, close to the English AEFI). It is any unfavourable sign, symptom, disease or laboratory finding that follows vaccination, whether or not it is causally related. Surveillance of these events keeps trust in the programme and catches errors or quality problems.
Key facts
- Most events are mild: pain, local redness, low fever.
- Anaphylaxis is rare and appears within minutes; that is why people are observed after vaccination.
- Fainting is a common anxiety reaction in adolescents.
- A coincidental event happens after the vaccine but not because of it.
Function
- Causality classification used internationally: vaccine product-related reaction, quality defect-related reaction, programmatic (immunization) error, anxiety-related reaction and coincidental event.
- Serious ESAVI are reported at once to the public health surveillance system (SIVIGILA), coordinated by the National Institute of Health (INS), and are investigated.
- The investigation reviews the vaccine, batch, cold chain, injection technique and patient history.
ESAVI severity according to the Ministry of Health
| Type | Features |
|---|---|
| Non-serious | Usually within 24 to 48 hours, not life-threatening, resolves without treatment and leaves no sequelae |
| Serious | Death, imminent threat to life, hospitalization or longer stay, persistent disability, or suspected congenital anomaly, fetal death or miscarriage |
Test yourself
Think of the answer, then tap the question to see it.
What does the acronym ESAVI stand for?
Evento supuestamente atribuible a la vacunación o inmunización: an event supposedly attributable to vaccination or immunization.
Which criteria make an ESAVI serious?
Death, imminent threat to life, needing or prolonging hospitalization, lasting disability, or suspected congenital anomaly, fetal death or miscarriage.
What is a programmatic error?
An event caused by how the vaccine was handled or given (cold chain, technique, dilution, route or site), not by the vaccine itself.
Why is a person observed for a few minutes after vaccination?
Because anaphylaxis, though rare, appears within minutes and needs immediate care.
Related
- The cold chain
- Colombia's PAI schedule (which vaccines, at what age)
- Vaccine types: live, inactivated, subunit, toxoid, mRNA, vector
- Type I hypersensitivity (immediate, IgE)
Related conditions
Educational content on the immune system; not a treatment or individual vaccination guide and no substitute for a health professional's advice. No doses are given.
Sources: Vigilancia en vacunación EAPV/ESAVI (Ministerio de Salud y Protección Social de Colombia (PAI), 2026); Contraindications and Precautions (Centers for Disease Control and Prevention (CDC), 2024).
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Representative model, for educational purposes only.