tetano
Editor, Senior Moderator
Vaccine
. 2022 Dec 19;S0264-410X(22)01566-3.
doi: 10.1016/j.vaccine.2022.12.041. Online ahead of print.
Factors associated with humoral immune response in older adults who received egg-free influenza vaccine
Katherine V Williams[SUP] 1 [/SUP], Krissy Moehling Geffel[SUP] 2 [/SUP], John F Alcorn[SUP] 3 [/SUP], Mary Patricia Nowalk[SUP] 4 [/SUP], Min Z Levine[SUP] 5 [/SUP], Sara S Kim[SUP] 6 [/SUP], Brendan Flannery[SUP] 7 [/SUP], Michael Susick[SUP] 8 [/SUP], Richard K Zimmerman[SUP] 9 [/SUP]
Affiliations
Abstract
Background: Immune responses to influenza vaccination tend to be lower among older, frequently vaccinated adults. Use of egg-free influenza vaccines is increasing, but limited data exist on factors associated with their immunogenicity in older adults.
Methods: Community-dwelling older adults ≥ 56 years of age were enrolled in a prospective, observational study of immunogenicity of 2018-2019 influenza vaccine. Hemagglutination inhibition (HAI) antibody titers were measured pre-vaccination (Day 0) and four weeks after vaccination (Day 28) to calculate geometric mean titers, seropositivity (HAI titers ≥ 1:40), seroconversion (fourfold rise in HAI titer with post-vaccination titer ≥ 1:40) and geometric mean fold rise (GMFR). Linear regression models assessed the association of predictors of GMFR for each vaccine antigen.
Results: Among 91 participants who received egg-free influenza vaccines, 84 (92.3 %) received quadrivalent recombinant influenza vaccine (RIV4, Flublok, Sanofi Pasteur), and 7 (7.7 %) received quadrivalent cell culture-based influenza vaccine (ccIIV4, Flucelvax, Seqirus). Pre-vaccination seropositivity was 52.8 % for A(H1N1), 94.5 % for A(H3N2), 61.5 % for B/Colorado and 48.4 % for B/Phuket. Seroconversion by antigen ranged from 16.5 % for A(H1N1) and B/Colorado to 37.4 % for A(H3N2); 40 participants failed to seroconvert to any antigen. Factors independently associated with higher GMFR in multivariable models included lower pre-vaccination HAI antibody titer for A(H1N1), B/Colorado and B/Phuket, and younger age for A(H1N1).
Conclusion: Overall pre-vaccination seropositivity was high and just over half of the cohort seroconverted to ≥ 1 vaccine antigen. Antibody responses were highest among participants with lower pre-vaccination titers. Among older adults with high pre-existing antibody titers, approaches to improve immune responses are needed.
Keywords: Adults; Egg-free influenza vaccine; Hemagglutination inhibition assay; Humoral response; Influenza.
. 2022 Dec 19;S0264-410X(22)01566-3.
doi: 10.1016/j.vaccine.2022.12.041. Online ahead of print.
Factors associated with humoral immune response in older adults who received egg-free influenza vaccine
Katherine V Williams[SUP] 1 [/SUP], Krissy Moehling Geffel[SUP] 2 [/SUP], John F Alcorn[SUP] 3 [/SUP], Mary Patricia Nowalk[SUP] 4 [/SUP], Min Z Levine[SUP] 5 [/SUP], Sara S Kim[SUP] 6 [/SUP], Brendan Flannery[SUP] 7 [/SUP], Michael Susick[SUP] 8 [/SUP], Richard K Zimmerman[SUP] 9 [/SUP]
Affiliations
- PMID: 36543682
- DOI: 10.1016/j.vaccine.2022.12.041
Abstract
Background: Immune responses to influenza vaccination tend to be lower among older, frequently vaccinated adults. Use of egg-free influenza vaccines is increasing, but limited data exist on factors associated with their immunogenicity in older adults.
Methods: Community-dwelling older adults ≥ 56 years of age were enrolled in a prospective, observational study of immunogenicity of 2018-2019 influenza vaccine. Hemagglutination inhibition (HAI) antibody titers were measured pre-vaccination (Day 0) and four weeks after vaccination (Day 28) to calculate geometric mean titers, seropositivity (HAI titers ≥ 1:40), seroconversion (fourfold rise in HAI titer with post-vaccination titer ≥ 1:40) and geometric mean fold rise (GMFR). Linear regression models assessed the association of predictors of GMFR for each vaccine antigen.
Results: Among 91 participants who received egg-free influenza vaccines, 84 (92.3 %) received quadrivalent recombinant influenza vaccine (RIV4, Flublok, Sanofi Pasteur), and 7 (7.7 %) received quadrivalent cell culture-based influenza vaccine (ccIIV4, Flucelvax, Seqirus). Pre-vaccination seropositivity was 52.8 % for A(H1N1), 94.5 % for A(H3N2), 61.5 % for B/Colorado and 48.4 % for B/Phuket. Seroconversion by antigen ranged from 16.5 % for A(H1N1) and B/Colorado to 37.4 % for A(H3N2); 40 participants failed to seroconvert to any antigen. Factors independently associated with higher GMFR in multivariable models included lower pre-vaccination HAI antibody titer for A(H1N1), B/Colorado and B/Phuket, and younger age for A(H1N1).
Conclusion: Overall pre-vaccination seropositivity was high and just over half of the cohort seroconverted to ≥ 1 vaccine antigen. Antibody responses were highest among participants with lower pre-vaccination titers. Among older adults with high pre-existing antibody titers, approaches to improve immune responses are needed.
Keywords: Adults; Egg-free influenza vaccine; Hemagglutination inhibition assay; Humoral response; Influenza.