Influenza-like illness after administration of COVID-19 vaccines
The Global Advisory Committee on Vaccine Safety (GACVS) of the World Health Organization (WHO) reviewed clinical
trial data and a summary of reports of influenza-like illnesses following COVID-19 vaccination, drawn from the WHO
Global Database of Individual Case Safety Reports (VigiBase). They report that symptoms of a flu-like illness can be
expected, as generally occurs with the body's immune response to vaccines. Symptoms are usually mild to moderate,
resolve within a few days, and may include headache, fatigue, muscle aches, fever, and chills.
These expected side effects of vaccination are more common in younger vaccine recipients (under age 55) than in older
In this respect, it is important to highlight the recommendation of GACVS regarding the possibility of short-term
adverse events after vaccination, which should be taken into account when planning the appropriate timing for
vaccinating health teams, and other workers who cover a specific type of service.
Source: GACVS COVID-19 Vaccine Safety subcommittee meeting to review reports on influenza-like illness in
individuals vaccinated with COVID-19 vaccines (8 Mar 2021).