Seasonal influenza vaccines induced high levels of neutralizing cross-reactive antibody responses against different genetic group influenza A(H1N1)pdm09 viruses. Issue 20 (6th May 2019)

• Record Type: Journal Article
• Authors: Haveri, Anu; Ikonen, Niina; Kantele, Anu; Anttila, Veli-Jukka; Ruotsalainen, Eeva; Savolainen-Kopra, Carita; Julkunen, Ilkka
• Is Part Of: Vaccine. Volume 37:Issue 20(2019)
• Page Start: 2731
• Page End: 2740
• Publication Date: 2019-05-06
• Subjects: Antibodies -- Microneutralization test -- Humoral immunity -- Influenza A -- Pandemic -- Vaccine; Vaccines -- Periodicals; 615.372
• DOI: 10.1016/j.vaccine.2019.03.078
• Languages: English
• ISSNs: 0264-410X

Abstract

Highlights: Antibody titers of the HI and MN assays correlated strongly positively. A HI titer of 40 was considered to be equivalent to a MN titer of 160. (day 21) GMTs were higher in the Fluarix group as compared to the Vaxigrip group. Pre-existing SR values were higher in 2012 compared to those seen in the 2010. Both vaccinations induced very high SRs. Abstract: Influenza A(H1N1)pdm09 viruses have been circulating throughout the world since the 2009 pandemic. A/California/07/2009 (H1N1) virus was included in seasonal influenza vaccines for seven years altogether, providing a great opportunity to analyse vaccine-induced immunity in relation to the postpandemic evolution of the A(H1N1)pdm09 virus. Serum antibodies against various epidemic strains of influenza A(H1N1)pdm09 viruses were measured among health care workers (HCWs) by haemagglutination inhibition and microneutralization tests before and after 2010 and 2012 seasonal influenza vaccinations. We detected high responses of vaccine-induced neutralizing antibodies to six distinct genetic groups. Our results indicate antigenic similarity between vaccine and circulating A(H1N1)pdm09 strains, and substantial vaccine-induced immunity against circulating epidemic viruses.