Estimates of Influenza Vaccine Effectiveness for 2007-2008 From Canada's Sentinel Surveillance System: Cross-Protection Against Major and Minor Variants
Estimates of Influenza Vaccine Effectiveness for 2007-2008 From Canada's Sentinel Surveillance System: Cross-Protection Against Major and Minor Variants
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DOI：
10.1093/infdis/jis283
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发表时间：
2012-06-15
影响因子：
6.4
通讯作者：
Petric, Martin
中科院分区：
文献类型：
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作者：
Janjua, Naveed Z.;Skowronski, Danuta M.;Petric, Martin
目标.评估2007-2008年流感季节流感疫苗的有效性（VE），并评估加拿大监控病毒演变和对VE影响的哨点监测系统。鼻/鼻咽拭子和流行病学详细信息收集自流感样疾病发作7天内就诊于哨点医生的患者。通过实时聚合酶链反应检测，病例的甲型/B型流感病毒呈阳性;对照组呈阴性。血凝抑制（HI）和基因测序探索病毒与疫苗的相关性。VE计算为1减去接种疫苗与未接种疫苗受试者流感的比值比，并对混杂因素进行调整。在1425名参与者中，21%的人接种了疫苗。在689例（48%）中检出流感病毒，其中663例分离株分型/亚型：189例（29%）为A/H1，210例（32%）为A/H3，264例（40%）为B。在A/H1N1分离株中，6%显示出与疫苗的轻微HI抗原错配，基于遗传特性的变异更大。所有A/H3 N2分离株均表现出中度抗原错配，98%的B型流感病毒分离株表现出与疫苗的主要谱系水平错配。A/H1N1、A/H3 N2和B组分的校正VE分别为69%（95%置信区间[CI]，44%-83%）、57%（95% CI，32%-73%）和55%（95% CI，32%-70%），总体VE为60%（95% CI，45%-71%）。流感病毒的详细抗原和基因型分析与VE的流行病学估计一致，显示交叉保护。一个常规的哨点监测系统，结合详细的病毒和VE监测每年，在加拿大建模，可以指导改进疫苗的选择和保护。
Objectives. To estimate influenza vaccine effectiveness (VE) for the 2007-2008 season and assess the sentinel surveillance system in Canada for monitoring virus evolution and impact on VE.Methods. Nasal/nasopharyngeal swabs and epidemiologic details were collected from patients presenting to a sentinel physician within 7 days of influenza-like illness onset. Cases tested positive for influenza A/B virus by real-time polymerase chain reaction; controls tested negative. Hemagglutination inhibition (HI) and gene sequencing explored virus relatedness to vaccine. VE was calculated as 1 minus the odds ratio for influenza in vaccinated versus nonvaccinated participants, with adjustment for confounders.Results. Of 1425 participants, 21% were vaccinated. Influenza virus was detected in 689 (48%), of which isolates from 663 were typed/subtyped: 189 (29%) were A/H1, 210 (32%) were A/H3, and 264 (40%) were B. Of A/H1N1 isolates, 6% showed minor HI antigenic mismatch to vaccine, with greater variation based on genetic identity. All A/H3N2 isolates showed moderate antigenic mismatch, and 98% of influenza B virus isolates showed major lineage-level mismatch to vaccine. Adjusted VE for A/H1N1, A/H3N2, and B components was 69% (95% confidence interval [CI], 44%-83%), 57% (95% CI, 32%-73%), and 55% (95% CI, 32%-70%), respectively, with an overall VE of 60% (95% CI, 45%-71%).Conclusions. Detailed antigenic and genotypic analysis of influenza viruses was consistent with epidemiologic estimates of VE showing cross-protection. A routine sentinel surveillance system that combines detailed virus and VE monitoring annually, as modeled in Canada, may guide improved vaccine selection and protection.