老年人接种三价流感病毒裂解疫苗的免疫原性评价

Evaluation of immunogenicity of trivalent split-vinus influenza vaccine among elderly populations

目的分析宁波市江北区老年人群流感病毒免疫水平及接种三价流感病毒裂解疫苗(TIV)后的免疫原性,为促进老年人群流感疫苗接种提供依据。方法于2020年9—11月在宁波市江北区招募≥60岁老年人为调查对象,根据接种意向分别纳入接种组和对照组。采用微量血凝抑制试验测定受试前和受试后30 d A(H1N1)、A(H3N2)和BV流感病毒血凝抑制抗体滴度,分析受试前后的抗体保护率、抗体几何平均滴度(GMT)和抗体阳转率。结果纳入接种组和对照组各290人,其中男性均为132人,占45.52%。受试前2组A(H1N1)、A(H3N2)和BV抗体保护率和抗体GMT比较,差异无统计学意义(P>0.05)。受试后,接种组A(H1N1)、A(H3N2)和BV抗体保护率分别为98.62%、94.14%和88.28%,抗体GMT增长倍数分别为9.26、6.19和10.09,抗体阳转率分别为78.62%、68.28%和71.38%,均高于对照组(P<0.05)。接种组≥80岁组BV抗体GMT增长倍数(7.91)低于70~<80岁组(12.53)和60~<70岁组(13.32);BV抗体阳转率(62.57%)低于70~<80岁组(83.33%);A(H3N2)抗体阳转率(62.57%)低于60~<70岁组(91.30%);差异均有统计学意义(P<0.05)。结论宁波市江北区老年人A(H3N2)和BV流感病毒免疫水平仍较低,TIV在老年人群中具有良好的免疫原性。应重点提高60~<70岁人群接种率,针对≥80岁研发保护效果更好的流感疫苗。

ObjectiveTo investigate immune responses to influenza virus infections and the immunogenicity of trivalent split-virus influenza vaccine among elderly populations in Jiangbei District,Ningbo City,so as to provide the support for promoting influenza vaccination among elderly populations.Methods and older were recruited in Jiangbei District of Ningbo City from September to November,2020,and the participants were assigned to the vaccination group and the control group according to vaccination intention.The titers of haemagglutination inhibition(HI)antibodies against influenza viruses A(H1 N1 and H3 N2)and BV were measured using the micro HI test prior to vaccination and 30 days post-vaccination,and the protective rate,geometric mean titer(GMT)and seroconversion rate of antibodies were analyzed before and after vaccination.Results the vaccination group,including 132 men(45.52%),and 290 controls,including 132 men(45.52%).There were no significant differences between the vaccination group and the control group in terms of the protective rate or GMT of antibodies against influenza viruses A(H1 N1 and H3 N2)and BV prior to vaccination(P>0.05).Following vaccination,the protective rates of antibodies against influenza viruses A(H1 N1 and H3 N2)and BV were 98.62%,94.14%and88.28%,and the GMT of antibodies against influenza viruses A(H1 N1 and H3 N2)and BV increased by 9.26,6.19 and 10.09 folds,while the seroconversion rates of antibodies against influenza viruses A(H1 N1 and H3 N2)and BV were 78.62%,68.28%and 71.38%,respectively.The protective rates,GMT and seroconversion rates of antibodies against influenza viruses A(H1 N1 and H3 N2)and BV were all significantly greater in the vaccination group than in the control group post-vaccination(P<0.05).A lower increase was seen in the GMT of antibodies against the influenza virus BV among residents at ages of 80 years and older(increase by 7.91 folds)than among residents at ages of 70 to79 years(increase by 12.53 folds)and 60 to 69 years(increase by 13.32 folds)in the vaccination group post-vaccination(P<0.05),and the seroconversion rate of antibodies against the influenza virus BV was significantly lower in residents at ages of 80 years and older(62.57%)than in those at ages of 70 to 79 years(83.33%)(P<0.05),while the positive conversion rate of antibodies against the influenza virus A(H3 N2)was significantly lower in residents at ages of 80 years and older(62.57%)than in those at ages of 60 to 69 years(91.30%)(P<0.05).ConclusionsLow-level immune responses are detected to antibodies against influenza virus A(H3 N2)and BV among elderly populations in Jiangbei District of Ningbo City,and trivalent split-virus influenza vaccine shows a high immunogenicity among elder populations.An emphases on improvements in coverage of influenza vaccination among elderly populations at ages of 60 to69 years,and development of influenza vaccines with a higher protective efficacy for residents at ages of 80 years and older are recommended.