Infectious Diseases| May 01 2000 Effect of Intra-Nasal Influenza Vaccine on a Variant Not in the Vaccine AAP Grand Rounds (2000) 3 (5): 49–50. https://doi.org/10.1542/gr.3-5-49 Views Icon Views Article contents Figures & tables Video Audio Supplementary Data Peer Review Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Cite Icon Cite Search Site Citation Effect of Intra-Nasal Influenza Vaccine on a Variant Not in the Vaccine. AAP Grand Rounds May 2000; 3 (5): 49–50. https://doi.org/10.1542/gr.3-5-49 Download citation file: Ris (Zotero) Reference Manager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search toolbar search search input Search input auto suggest filter your search All PublicationsAll JournalsAAP Grand RoundsPediatricsHospital PediatricsPediatrics In ReviewNeoReviewsAAP NewsAll AAP Sites Search Advanced Search Topics: influenza vaccines, nose, vaccines Source: Belshe RB, Gruber WC, Mendelman P. Efficacy of vaccination with live attenuated, cold-adapted, trivalent, intranasal influenza virus vaccine against a variant (A/Sydney) not contained in the vaccine. J Pediatrics. 2000;136:168–175. Belshe and colleagues carried out a 2-year, US, multi-center, double-blinded, placebo-controlled efficacy trial of a live attenuated, cold-adapted, trivalent influenza vaccine administered to young children by nasal spray. Subjects were re-vaccinated yearly, and the vaccine was reformulated each year with the same strains used in inactivated influenza vaccines. In year 1 the efficacy of the nasal spray vaccine was 95% (95% CI, 88–97%) against A/H3N2/Wuhan/359/95-like virus. In year 2 the investigators had an opportunity to study the protective efficacy of the nasal spray vaccine against an epidemic influenza A strain that was antigenically different from the strains in the vaccine. Active surveillance of study subjects was carried out through the influenza season. In year 2, 1,358 children 26–85 months of age received vaccine or placebo spray, representing 85% of the original study group from year 1. The nasal spray vaccine was well-tolerated, lacked serious side effects, and was immunogenic. After revaccination, 82-100% of vaccine recipients and 26-65% of placebo recipients were seropositive for various influenza strains, including strains incorporated in the vaccine as well as influenza A/Sydney/H3N2, which was not included. In year 2, influenza A/Sydney/H3N2 caused 66 of 70 proven cases of influenza A. Despite A/Sydney not being included in the vaccine, the intranasal vaccine was 86% protective against infection, including lower respiratory disease, with influenza A/Sydney. Belshe and co-workers previously reported the striking efficacy of their year 1 (1996–1997) vaccine trial, when the vaccine strains matched the dominant circulating wild strains.1 In 1997–1998 (year 2 in Belshe’s study), the influenza A epidemic turned out to be caused largely by a variant (A/Sydney/H3N2) not included in the vaccine, providing an opportunity to assess the vaccine’s immunogenicity and protection against that heterologous strain. Not only was the vaccine highly effective against the A/Sydney/H3N2 strain, it appears that the live attenuated vaccine may provide superior immunity compared to the inactivated vaccine in years when there is a poor match between vaccine and wild type influenza viruses.2 That is, immunity against a broader spectrum of influenza viruses may result from immunization with the live attenuated vaccine. Two other interesting observations were made in this study: 1) the live attenuated vaccine virus was not spread to unvaccinated siblings or day care contacts, and 2) significant reductions in febrile otitis media and in serious febrile illnesses were seen in the vaccinees when compared to placebo recipients. The lack of spread to contacts has the benefit of reducing risk of spread to immunocompromised contacts who, theoretically, might be at increased risk of untoward effects of a live vaccine. Reduced rates of febrile otitis media in vaccinees support a significant role for viral agents like RSV and influenza virus in setting the stage for acute (usually bacterial) otitis media. Data like that provided by Belshe et al suggest... You do not currently have access to this content.