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Half- vs full-dose trivalent inactivated influenza vaccine (2004-2005): age, dose, and sex effects on immune responses.

Abstract

BACKGROUND

Optimal public health strategies for managing influenza vaccine shortages are not yet defined. Our objective was to determine the effects of age, sex, and dose on the immunogenicity of intramuscular trivalent inactivated vaccine (TIV).

METHODS

Healthy adults aged 18 to 64 years, stratified by age (18-49 and 50-64 years) and sex, were randomized to receive full- or half-dose TIV. Hemagglutination inhibition titers against vaccine antigens were measured before and 21 days after immunization. A primary outcome of noninferiority was defined as a difference of less than 20% in the upper 95% confidence interval (CI) of the proportion of subjects with strain-specific hemagglutination inhibition antibody titers of 1:40 or higher after vaccination. Secondary outcomes included geometric mean titers, after vaccination side effects, and occurrences of influenza-like illnesses.

RESULTS

Among previously immunized subjects (N = 1114) receiving half- vs full-dose TIV (age, 18-49 years, n = 284 [half] and n = 274 [full]; and age 50-64 years, n = 276 [half] and n = 280 [full]), CIs for proportions of subjects with hemagglutination inhibition antibody titers of 1:40 or higher excluded substantial reduction for all antigens in the 18- to 49-year age group and for B/Shanghai/361/2002 (B) and A/Fujian/411/2002 (A/H3N2) in the 50- to 64-year age group. Geometric mean titer in the female 18- to 49-year age group exceeded male responses for all strains: responses to half-dose TIV that were comparable with male full-dose responses for A/New Caledonia/20/99 (A/H1N1) antigen, 25.4 (95% CI, 20.9-30.9) vs 25.6 (95% CI, 21.3-30.9); A/H3N2 antigen, 60.8 (95% CI, 50.8-72.7) vs 44.1 (95% CI, 37.6-51.8); and B antigen, 64.4 (95% CI, 53.9-76.9) vs 60.7 (95% CI, 51.4-71.7) (findings were similar for the 50- to 64-year age group). Some injection site and systemic reactions (myalgias and/or arthralgias [P < .05], headache [P < .001], and impact of fatigue [P < .05]) were significantly lower in men. The relative risk of medical visits and hospitalizations for influenza-like illnesses were similar in the half- and full-dose groups regardless of age.

CONCLUSIONS

Antibody responses to intramuscular half-dose TIV in healthy, previously immunized adults were not substantially inferior to the full-dose vaccine, particularly for ages 18 to 49 years. Significantly higher geometric mean titer responses in women were identified for all ages, regardless of dose or influenza strain. Half-dose vaccination may be an effective strategy for healthy adults younger than 50 years in the setting of an influenza vaccine shortage.

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  • Authors+Show Affiliations

    ,

    Allergy-Immunology Department, Walter Reed Army Medical Center, Washington, DC 20307, USA. renata.engler@gmail.com

    , , , , , , , , , ,

    Source

    Archives of internal medicine 168:22 2008 Dec 08 pg 2405-14

    MeSH

    Adolescent
    Adult
    Age Factors
    Antibodies, Viral
    Female
    Humans
    Influenza Vaccines
    Male
    Middle Aged
    Prospective Studies
    Serologic Tests
    Sex Factors
    Single-Blind Method
    Young Adult

    Pub Type(s)

    Comparative Study
    Journal Article
    Randomized Controlled Trial
    Research Support, N.I.H., Extramural
    Research Support, U.S. Gov't, Non-P.H.S.
    Research Support, U.S. Gov't, P.H.S.

    Language

    eng

    PubMed ID

    19064822

    Citation

    Engler, Renata J M., et al. "Half- Vs Full-dose Trivalent Inactivated Influenza Vaccine (2004-2005): Age, Dose, and Sex Effects On Immune Responses." Archives of Internal Medicine, vol. 168, no. 22, 2008, pp. 2405-14.
    Engler RJ, Nelson MR, Klote MM, et al. Half- vs full-dose trivalent inactivated influenza vaccine (2004-2005): age, dose, and sex effects on immune responses. Arch Intern Med. 2008;168(22):2405-14.
    Engler, R. J., Nelson, M. R., Klote, M. M., VanRaden, M. J., Huang, C. Y., Cox, N. J., ... Treanor, J. J. (2008). Half- vs full-dose trivalent inactivated influenza vaccine (2004-2005): age, dose, and sex effects on immune responses. Archives of Internal Medicine, 168(22), pp. 2405-14. doi:10.1001/archinternmed.2008.513.
    Engler RJ, et al. Half- Vs Full-dose Trivalent Inactivated Influenza Vaccine (2004-2005): Age, Dose, and Sex Effects On Immune Responses. Arch Intern Med. 2008 Dec 8;168(22):2405-14. PubMed PMID: 19064822.
    * Article titles in AMA citation format should be in sentence-case
    TY - JOUR T1 - Half- vs full-dose trivalent inactivated influenza vaccine (2004-2005): age, dose, and sex effects on immune responses. AU - Engler,Renata J M, AU - Nelson,Michael R, AU - Klote,Mary M, AU - VanRaden,Mark J, AU - Huang,Chiung-Yu, AU - Cox,Nancy J, AU - Klimov,Alexander, AU - Keitel,Wendy A, AU - Nichol,Kristin L, AU - Carr,Warner W, AU - Treanor,John J, AU - ,, PY - 2008/12/10/pubmed PY - 2009/1/24/medline PY - 2008/12/10/entrez SP - 2405 EP - 14 JF - Archives of internal medicine JO - Arch. Intern. Med. VL - 168 IS - 22 N2 - BACKGROUND: Optimal public health strategies for managing influenza vaccine shortages are not yet defined. Our objective was to determine the effects of age, sex, and dose on the immunogenicity of intramuscular trivalent inactivated vaccine (TIV). METHODS: Healthy adults aged 18 to 64 years, stratified by age (18-49 and 50-64 years) and sex, were randomized to receive full- or half-dose TIV. Hemagglutination inhibition titers against vaccine antigens were measured before and 21 days after immunization. A primary outcome of noninferiority was defined as a difference of less than 20% in the upper 95% confidence interval (CI) of the proportion of subjects with strain-specific hemagglutination inhibition antibody titers of 1:40 or higher after vaccination. Secondary outcomes included geometric mean titers, after vaccination side effects, and occurrences of influenza-like illnesses. RESULTS: Among previously immunized subjects (N = 1114) receiving half- vs full-dose TIV (age, 18-49 years, n = 284 [half] and n = 274 [full]; and age 50-64 years, n = 276 [half] and n = 280 [full]), CIs for proportions of subjects with hemagglutination inhibition antibody titers of 1:40 or higher excluded substantial reduction for all antigens in the 18- to 49-year age group and for B/Shanghai/361/2002 (B) and A/Fujian/411/2002 (A/H3N2) in the 50- to 64-year age group. Geometric mean titer in the female 18- to 49-year age group exceeded male responses for all strains: responses to half-dose TIV that were comparable with male full-dose responses for A/New Caledonia/20/99 (A/H1N1) antigen, 25.4 (95% CI, 20.9-30.9) vs 25.6 (95% CI, 21.3-30.9); A/H3N2 antigen, 60.8 (95% CI, 50.8-72.7) vs 44.1 (95% CI, 37.6-51.8); and B antigen, 64.4 (95% CI, 53.9-76.9) vs 60.7 (95% CI, 51.4-71.7) (findings were similar for the 50- to 64-year age group). Some injection site and systemic reactions (myalgias and/or arthralgias [P < .05], headache [P < .001], and impact of fatigue [P < .05]) were significantly lower in men. The relative risk of medical visits and hospitalizations for influenza-like illnesses were similar in the half- and full-dose groups regardless of age. CONCLUSIONS: Antibody responses to intramuscular half-dose TIV in healthy, previously immunized adults were not substantially inferior to the full-dose vaccine, particularly for ages 18 to 49 years. Significantly higher geometric mean titer responses in women were identified for all ages, regardless of dose or influenza strain. Half-dose vaccination may be an effective strategy for healthy adults younger than 50 years in the setting of an influenza vaccine shortage. SN - 1538-3679 UR - https://www.unboundmedicine.com/medline/citation/19064822/Half__vs_full_dose_trivalent_inactivated_influenza_vaccine__2004_2005_:_age_dose_and_sex_effects_on_immune_responses_ L2 - https://jamanetwork.com/journals/jamainternalmedicine/fullarticle/10.1001/archinternmed.2008.513 DB - PRIME DP - Unbound Medicine ER -