流感疫苗的發展已六十餘年，至今仍然是流感防治措施當中最重要的一環。目前使用中的流感疫苗分為注射型非活性流感疫苗與鼻噴劑型活性減毒流感疫苗兩種，皆包含三種病毒株(A 型H1N1，A 型H3N2，及一種B 型流感病毒)的抗原，需要每年接種。注射非活性流感疫苗與鼻噴活性減毒流感疫苗接種在健康成人身上皆可達約85%的保護效力。疫苗併發最嚴重的副作用主要為立即性過敏，發生率約在1-10 個案例／每一百萬劑，發生時應馬上肌肉注射腎上腺素，並給予口服抗組織胺。全身性雞蛋過敏雖列為注射禁忌之一，其引發立即性過敏的機率在現今純化品質較佳的流感疫苗中乃微乎其微。Guillain-Barré 症候群經主動監測與季節性流感疫苗並無相關，而含汞疫苗也已證明對兒童並無影響。

Although more than 60 years have passed since the first influenza vaccine was developed, influenza vaccination is still now the primary method for preventing influenza and its severe complications. Two kinds of influenza vaccines are currently used: the inactivated influenza vaccine, and the live, attenuated influenza vaccine. Both vaccines contain three different immunogenic antigens for influenza A/H1N1, A/H3N2, and B.Vaccination should be administrated annually. Both vaccines can provide approximately 85% protective efficacy.Post-vaccination anaphylaxis is the most severe complication, but the incidence is as low as 1-10 cases per million shots. Although severe egg-allergy is one of the vaccinecontraindications, anaphylaxis rarely happened in egg-allergic vaccinees due to the improvement of vaccine purification. According to many active surveillance reports, seasonal influenza vaccinations do not cause Guillain-Barré syndrome. Furthermore,thimerosal-containing vaccines are safe to infants and children.