LAIV Effective in Children During an Outbreak of a Drifted Strain

Abstract

Infectious Diseases| November 01 2007 LAIV Effective in Children During an Outbreak of a Drifted Strain AAP Grand Rounds (2007) 18 (5): 57. https://doi.org/10.1542/gr.18-5-57 Views Icon Views Article contents Figures & tables Video Audio Supplementary Data Peer Review Share Icon Share Twitter LinkedIn Tools Icon Tools Get Permissions Cite Icon Cite Search Site Citation LAIV Effective in Children During an Outbreak of a Drifted Strain. AAP Grand Rounds November 2007; 18 (5): 57. https://doi.org/10.1542/gr.18-5-57 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: disease outbreaks, influenza, influenza vaccine, trivalent live attenuated, vaccines Source: Piedra PA, Gaglani MJ, Kozinetz CJ, et al. Trivalent live attenuated intranasal influenza vaccine administered during the 2003–2004 Influenza Type A (H3N2) outbreak provided immediate, direct, and indirect protection in children. Pediatrics. 2007;120(3):e553–e564; doi:10.1542/peds.2006–2836 Since 1998 investigators from Baylor College of Medicine, Houston, and Scott and White Clinic and Hospital and Health Plan, Temple, Texas, have been conducting an open label, non-randomized, community-based influenza vaccine trial in school children five to 18 years of age. For the 2003–2004 influenza season, eligible healthy children were given intranasal trivalent live attenuated influenza vaccine (LAIV-T), while those with underlying health conditions were given injected trivalent inactivated influenza vaccine (TIV). LAIV-T and TIV were administered in the intervention communities and TIV was given in the comparison communities, chosen because these communities were demographically similar and in close proximity, with the expectation that this would likely result in the same strain of influenza circulating in both areas and with similar temporal influenza outbreaks. Children eligible for either influenza vaccine who were not participating in the study could receive the vaccines from their providers as part of their routine care. Shortly after initiating immunizations, an early outbreak of influenza due to a drifted strain occurred between October and December 2003. Investigators took advantage of this unexpected event to determine the effectiveness of LAIV-T and TIV during an influenza outbreak when the dominant circulating strain was antigenically distinct from the vaccine strains. Main study outcomes included office visits for physician-diagnosed cases of pneumonia and influenza (P&I) and for medically attended acute respiratory illness (MAARI). Direct evidence of vaccine efficacy was evaluated by comparing age-specific rates for these outcomes among vaccine recipients and those who weren’t vaccinated in the intervention communities. Indirect evidence of efficacy was assessed by comparing age-specific MAARI rates in the intervention and comparison communities. Rates were compared before, during, and after the influenza outbreak. A total of 4,961 children who lived in the intervention communities received LAIV-T and 1,944 received TIV. Of the 897 children five through eight years of age eligible for a second dose of LAIV-T, only 163 (18.2%) received a second dose (75 received it on or after the last day of the outbreak). Of the 737 children of the same age group who received TIV, the number eligible for a second dose of TIV was not known; however, 36 received a second dose (eight on or after the last day of the outbreak). Approximately 58% of the first doses had been administered when the epidemic reached its peak. The influenza immunization coverage in the intervention communities was estimated to be approximately 31%. Age-specific influenza vaccine coverage was also estimated in both the intervention and comparison communities. The overall coverage with TIV was similar in the intervention (27.5%) and comparison communities (28.8%). However, the rate of use in the intervention communities was significantly higher in children under five years of age (28.5% vs 23.6%) and adults ≥65 years of age (61.4% vs 57.6%). In the... You do not currently have access to this content.