Sécurité des vaccins

Event Suspected to be Attributable to Vaccination or Immunization (ESAVI):

Any unfavorable and/or unintended health situation (sign, abnormal laboratory finding, symptom or disease) occurring after vaccination (or immunization) that does not necessarily have a causal relationship with the vaccination process or the vaccine.

They are classified as either non-serious (fever, local redness or pain, irritability, rash) or serious (aseptic meningitis, neurotropic disease, viscerotropic disease, thrombocytopenia, anaphylaxis, febrile convulsions, vaccine-associated poliomyelitis).

The application of a surveillance system varies according to the methods and mechanisms used for each phase of the process. 

Passive Surveillance is based on voluntary and spontaneous notifications of those who identify the adverse event in the health institution or by notification of the vaccinated person. 

Active Surveillance consists of the application of systematic search strategies for specific events in the community or in health institutions through a protocol with detailed instructions, to answer questions about the real frequency of an event and its association with the vaccine. 

The general objective of ESAVI surveillance at the national level is the early detection, notification, and analysis of events presumably attributable to vaccination. As such, a rapid and effective response can be organized to minimize the negative impact on vaccination, the health of individuals and on the immunization program, and prevent the occurrence of additional events or their recurrence. 

An essential component of the system is the communication component. Both crisis communication and risk communication decision makers and the community. With the information available from regulatory activities and from the surveillance vaccine safety, crises in the confidence of the population must be anticipated and managed appropriately, without negatively impacting the acceptability and the financing of the entire system. 

The information generated by the ESAVI surveillance system gives tools to all those responsible for vaccine safety to identify any risks that may arise from the interaction of the biological product with the recipient's immune system. It also helps identify deviations from the process of use of the vaccine or quality problems in the production of the vaccine, as well as discriminating against those erroneously associated with vaccination, among others. 

The principles of ESAVI surveillance will guide the actions of everyone involved, and direct them in situations where there is uncertainty or where there are no specific recommendations on how to proceed.

1. Humanization of surveillance
2. A focus on purpose
3. Quality of information
4. Confidentiality
5. Systemic approach
6. Interprogrammatic and interagency coordination
7. Optimal risk communication

An information systems development plan should be defined for vaccine safety in coordination with all the institutions involved. It should consider the necessary information technologies, the human, physical and economic resources, and the way to manage those resources. 

It must also establish the flow of notifications and information, analysis procedures, decision-making, and communication.

Image labels are in Spanish only

Schematic representation of the structure for data exchange at subnational, national and global levels (spanish only)

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