• As of 20 August 2021, 36,004,467 doses of the COVID-19 vaccine of Pfizer-BioNTech, 12,643,463 doses of the Moderna vaccine, and 2,780,120 doses of the AstraZeneca and the Covishield vaccine (AstraZeneca manufactured by the Serum Institute of India) had been administered.
  • There were 13,474 individual reports of adverse events following immunization (0.026% of doses administered). Of these, 3,549 reports were of serious events (0.007% of doses administered).
  • Of total reports, 35,969 reports were of adverse events following immunization (AEFI), of which 13,474 were for one or more events; the majority of these were for non-serious events such as injection-site reactions, paresthesia, headache, pruritus, dyspnea, fatigue, nausea, etc.

Following is an analysis of 555 of the 557 cases of myocarditis/pericarditis, including information on the vaccine administered: 

Source: Public Health Agency of Canada. Canadian COVID-19 vaccination safety report. Ottawa: Public Health Agency of Canada; 27 August 2021. Data reproduced by PAHO/WHO.



  • From 27 February to 15 July 2021, 993 people reported a total of 1,645 AEFI, out of a total of 4,466,346 doses of the three vaccines available in the country administered, with adverse events representing 0.037% of doses administered.
  • For the CoronaVac vaccine, reported AEFI represented 0.02% of doses administered, while for both PfizerBioNTech and AstraZeneca, AEFI amounted to 0.06% of doses administered.
  • The most frequently reported AEFI were injection-site pain, headache, muscle aches, malaise, diarrhea, tremor, and bronchospasm.
  • As of 15 July, 9 cases of serious AEFI (mostly deep-vein thrombosis) had been confirmed, representing 0.0002% of total doses administered. Another five AEFI are still under investigation and have not yet been confirmed. These include two reports of myocarditis in adolescents; of these, one individual was discharged, while the other is in recovery and doing well.



Consolidated number of reported adverse events and reporting rate (reports per 100,000 doses administered), by vaccine, for countries in the Americas that reported to the UMC or publicly+ as of 31 July 2021*

+ Countries included in the table are: Argentina, Barbados, Plurinational State of Bolivia, Brazil, Canada, Chile, Colombia, Costa Rica, Ecuador, El Salvador, United States, Honduras, Jamaica, Mexico, Panama, Paraguay, Peru, Saint Vincent and the Grenadines, Uruguay, and Bolivarian Republic of Venezuela.

*Indicates doses administered by countries reporting adverse events.


COVID-19 Vaccination in the Americas. Available at:  Accessed 30 July 2021.   

Adverse events: VigiBase database information as of 31 July; public country sources (epidemiological bulletins); and PAHO country reports.

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