544. Safety and Immunogenicity of a Quadrivalent Inactivated Influenza Vaccine (QIV) Containing Two A and Two B Strains among Persons ≥65 Years of Age
Session: Poster Abstract Session: Influenza Vaccines
Friday, October 21, 2011
Room: Poster Hall B1
Background: Two distinct B influenza lineages (Victoria and Yamagata) have co-circulated for over a decade, making it difficult to predict which will predominate the next season.  Consequently, the B strain selected in the spring for trivalent inactivated influenza vaccine (TIV) often fails to match the B strain that predominates in the fall.  Among elderly persons, type B is the second most common cause of influenza-related morbidity and mortality after H3N2.  QIV has been developed to address the frequent mismatches by incorporating a strain from each B lineage.

Methods: In a double-blind, controlled, multicenter study, 675 persons ≥ 65 years of age were randomized 1:1:1 to receive one IM dose of 2010-2011 TIV (B/Brisbane/60/2008 [Victoria lineage]), investigational TIV (B/Florida/04/2006 [Yamagata lineage]), or QIV (both B strains). All 3 vaccines contained the same H1N1 (A/California/07/2009) and H3N2 (A/Victoria/210/2009) strains. Safety was monitored for 21 days after vaccination. Blood specimens for immunogenicity (hemagglutination inhibition [HI] assay) were collected pre- and 21 days post-vaccination.

Results: 

Post-vaccination geometric mean titers (GMTs; 1/dil), seroprotection rates (≥1:40; SP), and seroconversion rates (4-fold rise; SC) are shown below.

 

 

QIV

(N=220)

2010-2011 TIV

(N=219)

Investigational TIV

(N=221)

H1N1

H3N2

B1

B2

H1N1

H3N2

B1

H1N1

H3N2

B2

GMT

231

501

73.8

61.1

269

291

57.9

271

360

54.8

SP (%)

91.4

100.0

77.7

73.2

91.3

95.4

71.7

91.9

95.9

67.4

SC (%)

65.9

69.1

28.6

33.2

66.7

55.7

18.7

72.9

62.9

31.2

B1 = B/Brisbane; B2 = B/Florida

The HI response to each A and B strain in QIV was non-inferior to the response with the respective strains in TIV based on GMT ratios (QIV/TIV; lower bound of 95% confidence interval of ratio > 0.66). Solicited injection-site reactions, systemic reactions, and unsolicited events were reported at similar rates among all 3 groups. None of 3 serious adverse events was considered related to any vaccine. 

Conclusion: These data indicate that the addition of a second B lineage strain to influenza vaccine does not adversely affect the safety or immunogenicity profile of QIV compared with TIV. QIV has the potential to be a useful alternative to TIV and offers the possibility of protection against both B lineages.


Subject Category: I. Adult and Pediatric Vaccines

David P. Greenberg, MD, FIDSA1, Corey Robertson, MD, MPH1, H. Keipp Talbot, MD, MPH2 and Michael D. Decker, MD, MPH1, (1)Sanofi Pasteur, Swiftwater, PA, (2)Vanderbilt Univ. Hosp., Nashville, TN

Disclosures:

D. P. Greenberg, Sanofi Pasteur: Employee, Salary

C. Robertson, Sanofi Pasteur: Employee, Salary

H. K. Talbot, Sanofi Pasteur: Investigator, Research support

M. D. Decker, Sanofi Pasteur: Employee, Salary

See more of: Influenza Vaccines
See more of: Poster Abstract Session

Findings in the abstracts are embargoed until 12:01 a.m. EST Thursday, Oct. 20 with the exception of research findings presented at IDSA press conferences.