Marchi Serena, Manini Ilaria, Kistner Otfried, Piu Pietro, Remarque Edmond J, Manenti Alessandro, Biuso Fabrizio, Carli Tommaso, Lazzeri Giacomo, Montomoli Emanuele, Trombetta Claudia Maria
Department of Molecular and Developmental Medicine, University of Siena, 53100 Siena, Italy.
Interuniversity Research Center on Influenza and Other Transmissible Infections (CIRI-IT), 16132 Genoa, Italy.
Vaccines (Basel). 2020 Nov 5;8(4):656. doi: 10.3390/vaccines8040656.
After the influenza H1N1 pandemic of 2009, the seasonal A/Brisbane/59/2007 strain was replaced by the A/California/07/2009 strain for the influenza virus vaccine composition. After several seasons with no indications on the occurrence of antigenic drift, A/Michigan/45/2015 was chosen as the H1N1 vaccine strain for the 2017/2018 season. Since the immune response to influenza is shaped by the history of exposure to antigenically similar strains, the potential cross-protection between seasonal human influenza vaccine strains and the emerging pandemic strains was investigated. Human serum samples were tested by hemagglutination inhibition and single radial hemolysis assays against A/Brisbane/59/2007, A/California/07/2009, and A/Michigan/45/2015 strains. Strong cross-reactions between A/California/07/2009 and A/Michigan/45/2015 strains were observed in 2009/2010, most likely induced by the start of the 2009 pandemic, and the subsequent post-pandemic seasons from 2010/2011 onward when A/California/07/2009 became the predominant strain. In the 2014/2015 season, population immunity against A/California/07/2009 and A/Michigan/45/2015 strains increased again, associated with strong cross-reactions. Whereas hemagglutination inhibition assay has a higher sensitivity for detection of new seasonal drift, the single radial hemolysis assay is an excellent tool for determining the presence of pre-existing immunity, allowing a potential prediction on the booster potential of influenza vaccines against newly emerging drifted strains.
2009年甲型H1N1流感大流行之后，季节性A/布里斯班/59/2007毒株被A/加利福尼亚/07/2009毒株取代，用于流感病毒疫苗的成分。在经历了几个没有抗原漂移迹象的季节后，A/密歇根/45/2015被选为2017/2018季节的H1N1疫苗毒株。由于对流感的免疫反应受接触抗原相似毒株历史的影响，因此对季节性人流感疫苗毒株与新出现的大流行毒株之间的潜在交叉保护作用进行了研究。采用血凝抑制试验和单向辐射溶血试验，针对A/布里斯班/59/2007、A/加利福尼亚/07/2009和A/密歇根/45/2015毒株检测人血清样本。2009/2010年观察到A/加利福尼亚/07/2009和A/密歇根/45/2015毒株之间有强烈的交叉反应，这很可能是由2009年大流行开始以及随后从2010/2011年起A/加利福尼亚/07/2009成为优势毒株的大流行后季节所诱导的。在2014/2015季节，针对A/加利福尼亚/07/2009和A/密歇根/45/2015毒株的群体免疫力再次上升，这与强烈的交叉反应有关。虽然血凝抑制试验在检测新的季节性漂移方面具有更高的灵敏度，但单向辐射溶血试验是确定预先存在免疫力的优秀工具，能够对流感疫苗针对新出现的漂移毒株的加强免疫潜力进行潜在预测。
