543. Immunogenicity and Safety of a High Dose Influenza Vaccine in the Elderly Compared with FluzoneŽ in Young Adults and the Elderly
Session: Poster Abstract Session: Influenza Vaccines
Friday, October 21, 2011
Room: Poster Hall B1
Background: Antibody responses to influenza vaccines are substantially lower in the elderly compared to young adults. Fluzone® High-Dose (HD), a US-licensed high-dose influenza vaccine containing 60 µg hemagglutinin (HA) per strain, was developed recently to improve antibody responses in the elderly.

Methods: 639 subjects ≥ 65 years of age were randomized to receive HD or Fluzone (15 µg HA per strain), and 186 adults 18-49 years of age received Fluzone. Hemagglutination inhibition (HI) titers were measured before and 28 days post-vaccination. 

Results: Among the elderly, all post-vaccination HI antibody responses were higher in the HD group compared to the Fluzone group. When compared to young adults receiving Fluzone vaccine, geometric mean titers (GMTs) were higher in the elderly HD group for H3N2 but lower for H1N1; seroconversion (4-fold rise) rates were higher in the HD group for H1N1 but lower for the B strain; seroprotection (≥1:40) rates were similar for all three strains. Solicited injection-site and systemic reactions and unsolicited events were reported more frequently in the elderly HD group compared to the elderly Fluzone group, but more frequently in the young adult Fluzone group compared to either elderly group.  

 

 

Elderly

Fluzone High-Dose

N=320

Elderly

Fluzone

N=319

Young adults

Fluzone

N=186

 

Demographic

 

     Male

42.8%

44.8%

34.9%

 

     Mean Age ± SD

73.0 ± 6.0

73.4 ± 5.9

32.2 ± 8.5

 

     Caucasian

93.8%

92.8%

73.7%

 

GMT (95% CI)

     H1N1

229.8 (201.6; 261.8)

109.1 (94.9; 125.5)

337.3 (286.4; 397.3)

     H3N2

497.2 (442.4; 558.6)

281.5 (250.6; 316.2)

382.7 (328.0; 446.5)

     B

58.9 (53.6; 64.7)

43.5 (39.4; 48.1)

69.7 (60.4; 80.5)

Seroconversion, Percentage (95% CI)

     H1N1

81.1 (76.3; 85.2)

61.4 (55.8; 66.8)

61.4 (54.0; 68.5)

     H3N2

55.2 (49.5; 60.8)

38.0 (32.6; 43.6)

51.6 (44.2; 59.0)

     B

25.2 (20.5; 30.4)

8.9 (6.0; 12.6)

44.0 (36.7; 51.5)

Seroprotection, Percentage (95% CI)

     H1N1

93.4 (90.1; 95.9)

79.7 (74.9; 84.0)

96.7 (93.0; 98.8)

     H3N2

99.1 (97.3; 99.8)

97.2 (94.7; 98.7)

98.9 (96.1; 99.9)

     B

77.0 (71.9; 81.5)

61.4 (55.8; 66.8)

78.3 (71.6; 84.0)

 

Conclusion: Fluzone High-Dose induced higher antibody responses compared to Fluzone in the elderly and enhanced antibody responses to levels similar to, and in some cases higher than, those observed in young adults receiving Fluzone.


Subject Category: I. Adult and Pediatric Vaccines

Peter Tsang, MD1, Geoffrey Gorse, MD2, Cynthia B. Strout, MD3, Malcolm Sperling, M.D.4, Carlos DiazGranados, MD1, David Greenberg, MD1, Ayca Ozol-Godfrey1, Victoria Landolfi1 and Martine Denis, DVM5, (1)Sanofi Pasteur, Swiftwater, PA, (2)Dept. of Vet. Med. Ctr. & Saint Louis Univ., St. Louis, MO, (3)Coastal Carolina Research Center, Mount Pleasant, SC, (4)Edinger Medical Group , Fountain Valley, CA, (5)Sanofi Pasteur, Marcy l'Etoile, France

Disclosures:

P. Tsang, sanofi pasteur: Employee, Salary

G. Gorse, None

C. B. Strout, None

M. Sperling, None

C. DiazGranados, None

D. Greenberg, None

A. Ozol-Godfrey, None

V. Landolfi, sanofi pasteur: Employee, Salary

M. Denis, None

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