Risk of Worsening Asthma From LAIV Unfounded
Exacerbation rates were higher for IIV during the risk interval of 1-14 days after vaccination than for LAIV.
Use of live attenuated influenza vaccine (LAIV) does not present an increased risk for exacerbation of asthma in young children, according to a study published in Vaccine.1 In fact, for children aged 2 years or older with asthma or a history of asthma, the LAIV had a reduced risk compared with the inactivated influenza vaccine (IIV).
Recommendations from the Advisory Committee on Immunization Practices (ACIP) released from 2007 to 20142-6 have specifically cautioned against the use of LAIV in children with asthma, based on limited evidence from 2 studies of potential wheezing as an adverse effect, although asthma was not a study outcome in either case, the authors reported.7,8 A number of other studies conducted since then found no indication of exacerbations associated with the use of the live virus9-16; however, this was not addressed in the ACIP recommendations.
For the current study, the investigators looked retrospectively at the actual incidence of adverse events in a large-scale database from the Kaiser-Permanente Northern California healthcare system. They captured 387,633 immunization records for children aged 2 through 17 years with any history of asthma who were vaccinated between July 1, 2007, and March 31, 2014. As adherence to ACIP recommendations was at the discretion of the medical provider, the authors found a substantial number of children in the database with asthma who were administered live virus: 56,826 (15%) were given LAIV compared with 330,807 (85%) who received IIV.
Exacerbations of asthma were associated with having a recent history of asthma, regardless of the type of vaccine administered. Confirmed exacerbations treated as outpatients occurred in 70% of both the LAIV (591/846) and IIV groups (403/572) with a remote history. Surprisingly, the exacerbation rates were higher for IIV during the risk interval of 1 to 14 days after vaccination than after LAIV (257/100,000 and 113/100,000, respectively).
The important difference, the authors noted, was that the exacerbation trends for LAIV in children with asthma indicated a mild improvement compared with the IIV. Risk rates for an inpatient or emergency department-treated exacerbation among IIV-vaccinated children showed little change between the risk interval and the comparison interval (odds ratio, 0.97; 95% CI, 0.82-1.15), whereas the comparative rate among children given LAIV was lower during the risk interval than the comparison interval (odds ratio, 0.39, 95% CI, 0.17-0.90). Likewise, the risk for an outpatient exacerbation was also lower in the LAIV group, while remaining the same in the IIV group.
"We cannot speak as to whether or not the findings are sufficient to modify ACIP guidelines," coauthor G. Thomas Ray, MBA, senior data consultant at the Kaiser Permanente Vaccine Study Center and Division of Research, Kaiser Permanente Medical Care Program, Oakland, California, told Pulmonology Advisor. He added that despite recommendations in the 2016 season not to use the LAIV because of poor effectiveness, "some providers may elect to use LAIV, it continues to be recommended outside the [United States], and may again be recommended for use in the [United States] in future seasons."
G. Thomas Ray has received research support on grants to Kaiser Permanente Division of Research in the past 3 years from Pfizer, Merck & Co, Genentech, and Purdue Pharma. Roger Baxter has received research grants through his institution from MedImmune, GlaxoSmithKline (GSK), Sanofi Pasteur, and Protein Science. Nicola P. Klein has received research grants through her institution from MedImmune, GSK, Sanofi Pasteur, Novartis (now GSK), Protein Science, Merck & Co, and Pfizer.
- Ray GT, Lewis N, Goddard K, et al. Asthma exacerbations among asthmatic children receiving live attenuated versus inactivated influenza vaccines. Vaccine. 2017;35:2668-2675. doi: 10.1016/j.vaccine.2017.03.082
- Centers for Disease Control and Prevention (CDC). Expansion of use of live attenuated vaccine (FluMist) to children aged 2-4 years and other FluMist changes for the 2007-08 influenza season. MMWR Morb Mortal Wkly Rep. 2007;56:1217-1219.
- Fiore AE, Shay DK, Broder K, et al; Advisory Committee on Immunization Practices (ACIP). Prevention and control of influenza: recommendations of the Advisory Committee on Immunization Practices (ACIP), 2008. MMWR Recomm Rep. 2008;57:1-60.
- Grohskopf LA, Uyeki TM, Bresee JS, Cox N. Prevention and control of influenza vaccines: recommendations of the advisory committee on immunization practices, United States, 2012–13 influenza season. MMWR Morb Mortal Wkly Rep. 2012;61:612-618.
- Grohskopf LA, Olsen SJ, Sokolow LZ, et al; Centers for Disease Control and Prevention. Prevention and control of seasonal influenza with vaccines: recommendations of the Advisory Committee on Immunization Practices (ACIP) – United States, 2014-15 influenza season. MMWR Morb Mortal Wkly Rep. 2014;63:691-697.
- Grohskopf LA, Sokolow LZ, Olsen SJ, Bresee JS, Broder KR, Karron RA. Prevention and control of influenza with vaccines: recommendations of the advisory committee on immunization practices, United States, 2015-16 influenza season. MMWR Morb Mortal Wkly Rep. 2015;64:818-825.
- Bergen R, Black S, Shinefield H, et al. Safety of cold-adapted live attenuated influenza vaccine in a large cohort of children and adolescents. Pediatr Infect Dis J. 2004;23:138-144.
- Belshe RB, Edwards KM, et al; CAIV-T Comparative Efficacy Study Group. Live attenuated versus inactivated influenza vaccine in infants and young children. N Engl J Med. 2007;356:685-696. doi: 10.1056/NEJMoa065368
- Toback SL, Ambrose CS, Eaton A, et al. A postlicensure evaluation of the safety of Ann Arbor strain live attenuated influenza vaccine in children 24–59 months of age. Vaccine. 2013;31:1812-1818. doi: 10.1016/j.vaccine.2013.01.055
- Baxter R, Toback SL, Sifakis F, et al. A postmarketing evaluation of the safety of Ann Arbor strain live attenuated influenza vaccine in children 5 through 17 years of age. Vaccine. 2012;30:2989-2998. doi: 10.1016/j.vaccine.2012.02.039
- Gaglani MJ, Piedra PA, Riggs M, Herschler G, Fewlass C, Glezen WP. Safety of the intranasal, trivalent, live attenuated influenza vaccine (LAIV) in children with intermittent wheezing in an open-label field trial. Pediatr Infect Dis J. 2008;27:444-452. doi: 10.1097/INF.0b013e3181660c2e
- Fleming DM, Crovari P, Wahn U, et al; CAIV-T Asthma Study Group. Comparison of the efficacy and safety of live attenuated cold-adapted influenza vaccine, trivalent, with trivalent inactivated influenza virus vaccine in children and adolescents with asthma. Pediatr Infect Dis J. 2006;25:860-869. doi: 10.1097/01.inf.0000237797.14283.cf
- Ashkenazi S, Vertruyen A, Aristegui J, et al; CAIV-T Study Group. Superior relative efficacy of live attenuated influenza vaccine compared with inactivated influenza vaccine in young children with recurrent respiratory tract infections. Pediatr Infect Dis J. 2006;25:870-879. doi: 10.1097/01.inf.0000237829.66310.85
- Tennis P, Toback SL, Andrews E, McQuay LJ, Ambrose CS. A postmarketing evaluation of the frequency of use and safety of live attenuated influenza vaccine use in nonrecommended children younger than 5 years. Vaccine. 2011;29:4947-4952. doi: 10.1016/j.vaccine.2011.04.113
- Tennis P, Toback SL, Andrews EB, et al. A US postmarketing evaluation of the frequency and safety of live attenuated influenza vaccine use in nonrecommended children younger than 5 years: 2009-2010 season. Vaccine. 2012;30:6099-6102. doi: 10.1016/j.vaccine.2012.07.031
- Cates CJ, Rowe BH. Vaccines for preventing influenza in people with asthma. Cochrane Database Syst Rev. 2013(2):CD000364. doi: 10.1002/14651858.CD000364.pub4