This general practice is necessary after administration of any vaccine to monitor a person’s reaction to the vaccine and ensure first aid is available if they experience any severe allergic reactions, including anaphylactic shock. Anaphylactic reactions can be potentially life-threatening if not detected and treated promptly. Symptoms can include a rapid, weak pulse, skin rash, fainting, wheezing, nausea and vomiting.

Recommendations regarding the duration of the observation time may vary by country. In general, upon receiving the vaccine a person should be requested to stay for 15–30 minutes at the healthcare facility or community vaccination center where healthcare professionals are available in case of any immediate reactions to provide first aid.

In general, persons with a severe allergic reaction to the first dose should not receive additional doses of the same vaccine. In addition, individuals should alert their local health providers following vaccination if they experience any unexpected side effects or other health events.