The most common unwanted effects are nasal congestion and runny nose. Other possible unwanted effects include: headache, sore throat, malaise, muscle aches, cough, and chills.

Influenza vaccine-live, attenuated is administered by nasal spray. A vaccine that is live and attenuated contains a living version of the virus that has been attenuated, or made very weak. This helps the body to create an antibody to the virus, without making the body sick with the virus.

Do not use live, attenuated influenza vaccine:​

• in children under the age of 2 years due to increased risk of the development of wheezing
• are under the age of 18 years receiving aspirin or medicines containing aspirin;
• have severe asthma or active wheezing;
• are immunosuppressed due to disease or drug treatment, or associate with people who are immunosuppressed.

Getting the live, attenuated influenza vaccine should usually be postponed in serious acute illness until symptoms have resolved. It should not be delayed because of minor acute illness, with or without fever. If nose congestion is serious enough to prevent proper administration of the nasal spray, the inactivated vaccine can be used or the administration of the live vaccine should be delayed until the congestion has cleared.

Administration during pregnancy: the live, attenuated vaccine should not be given to pregnant women or women planning on pregnancy
Administration during breastfeeding: Considered safe.