Immunogenicity of a trivalent influenza vaccine and persistence of induced immunity in adults aged ≥60 years in Taizhou City, Zhejiang Province, China, during the 2018–2019 season
Yearly administration of influenza vaccine with recommendations can help control seasonal influenza epidemics in adults aged ≥60 years. Here, we describe the results of a prospective study observing the immunogenicity and persistence of induced immunity of a trivalent inactivated split-virion influe...
| Main Authors: | , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Taylor & Francis Group
2022-11-01
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| Series: | Human Vaccines & Immunotherapeutics |
| Subjects: | |
| Online Access: | http://dx.doi.org/10.1080/21645515.2022.2071061 |
| Summary: | Yearly administration of influenza vaccine with recommendations can help control seasonal influenza epidemics in adults aged ≥60 years. Here, we describe the results of a prospective study observing the immunogenicity and persistence of induced immunity of a trivalent inactivated split-virion influenza vaccine (TIV) in adults aged ≥60 years during the 2018–2019 season in Taizhou City, Zhejiang Province in China. A total of 422 participants completed the study period. Vaccinated participants (284) received a single dose of TIV, but unvaccinated participants (138) didn’t receive any vaccine. Study participants vaccinated with TIV had significantly higher GMTs of Hemagglutination Inhibition (HI) antibodies against AH1N1, AH2N3, and B/Victoria strains (all p < .0001) at day 30 post-vaccination compared with unvaccinated participants, but the antibody response to the B/Victoria strain was the weakest. Rates of seroprotection and seroconversion were generally higher in the TIV-vaccinated group. At day 180 post-vaccination, the seroconversion rates (95%CI) in the vaccinated group were 99.6% (99.0%–100.3%), 97.9% (96.2%–99.6%), and 68.3% (62.9%–73.8%) for antibodies against three influenza strains, respectively; these rates were significantly different compared with unvaccinated group only for strains AH3N2 and B/Victoria (p = .002 and p < .0001, respectively). These results confirm that in adults aged ≥60 years, a single dose of TIV can induce a protective immune response against influenza, but the protective HI antibody levels induced against strain B/Victoria do not persist through 6 months. |
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| ISSN: | 2164-5515 2164-554X |