Comparative Efficacy of Inactivated and Live Attenuated Influenza Vaccines

• Published in: The New England journal of medicine Vol. 361; no. 13; pp. 1260 - 1267
• Main Authors: Monto, Arnold S, Ohmit, Suzanne E, Petrie, Joshua G, Johnson, Emileigh, Truscon, Rachel, Teich, Esther, Rotthoff, Judy, Boulton, Matthew, Victor, John C
• Format: Journal Article
• Language: English
• Published: Waltham, MA Massachusetts Medical Society 24.09.2009
• Subjects: Adolescent; Adult; Biological and medical sciences; Double-Blind Method; Female; General aspects; Human viral diseases; Humans; Incidence; Infectious diseases; Influenza; Influenza A Virus, H3N2 Subtype - isolation & purification; Influenza B virus - isolation & purification; Influenza Vaccines - adverse effects; Influenza Vaccines - immunology; Influenza, Human - immunology; Influenza, Human - prevention & control; Influenza, Human - virology; Licenses; Male; Medical sciences; Risk; Treatment Outcome; Vaccines; Vaccines, Attenuated - adverse effects; Vaccines, Attenuated - immunology; Vaccines, Inactivated - adverse effects; Vaccines, Inactivated - immunology; Viral diseases; Viral diseases of the respiratory system and ent viral diseases; Viruses; Young Adult; Infection; Medicine; Viral disease; Treatment efficiency; Influenza; Attenuated strain; Comparative study
• ISSN: 0028-4793; 1533-4406; 1533-4406
• DOI: 10.1056/NEJMoa0808652

Data are scarce regarding the comparative efficacies of the inactivated (intramuscular administration) and live attenuated (intranasal administration) seasonal influenza vaccines. During the 2007–2008 influenza season, 1952 healthy young adults were enrolled in a randomized, double-blind, placebo-controlled study of these two vaccines. The inactivated vaccine was found to have an absolute efficacy of 68%, whereas the live attenuated vaccine had an absolute efficacy of 36%. The inactivated (intramuscular administration) vaccine was found to have an absolute efficacy of 68%, whereas the live attenuated (intranasal administration) vaccine had an absolute efficacy of 36%. Two different types of vaccine for the prevention of seasonal influenza are currently licensed, one containing inactivated viruses and the other containing live attenuated viruses. Both vaccines are trivalent, with the three components updated annually as needed on the basis of national and international recommendations. 1 The efficacy of both vaccines can be affected by a number of factors, including the age and health of the vaccine recipients, and by the extent of antigenic similarity between the strains included in the vaccines and those that actually circulate months later. 2 – 6 Thus, there can be differences in efficacy from year to year. . . .