Okinawa Prefectural Institute of Health and Environment, Okinawa, Japan.
Okinawa Prefectural Institute of Health and Environment, Okinawa, Japan.
Vaccine. 2020 Feb 28;38(10):2361-2367. doi: 10.1016/j.vaccine.2020.01.067. Epub 2020 Feb 6.
Okinawa Prefecture, Japan, experienced a large measles outbreak from March to May 2018. During this outbreak, there were 99 laboratory-confirmed cases and 14 vaccine-associated measles cases. In addition to the reinforcement of routine immunization, Okinawa prefectural government introduced emergent measles-containing vaccination recommendations for infants aged 6-11 months as part of the outbreak response. Increased concern exists in Okinawa about measles in infants following a previous outbreak from 1998 to 2001, when nine children including four infants died. Of 8062 infants aged 6-11 months who received measles-containing vaccine (MCV), six developed vaccine-associated measles; incidence was 0.74 per 1000 doses (95%CI 0.27-1.62). This was similar to that of first dose routine immunization recipients at one year of age (IR 0.60, 95%CI 0.20-1.78). Among 14 vaccine-associated measles cases, throat swab samples showed the highest positive rate (92.9%) by real-time reverse transcription polymerase chain reaction (RT-qPCR), followed by urine (25.0%) and whole blood (7.7%) samples. Furthermore, one throat swab sample classified as equivocal by RT-qPCR was positive by conventional RT-PCR (RT-PCR). During an outbreak, it is critical to distinguish between cases with measles-like symptoms caused by wild circulating virus and those caused by vaccine-derived virus as accurately and urgently as possible because the public health response will be quite different. No infant deaths were observed during this outbreak, and no severe adverse events following immunization were seen among infants 6-11 months old who were given MCV as a public health response. Thus, we conclude that introduction of emergent MCV was effective and describing the characteristics of vaccine-associated measles cases during a measles outbreak will be helpful for future outbreak response efforts.
日本冲绳县于 2018 年 3 月至 5 月期间爆发了大规模麻疹疫情。在此期间，共确诊实验室确诊病例 99 例，疫苗相关麻疹病例 14 例。除加强常规免疫外，冲绳县政府还在疫情应对期间，针对 6-11 月龄婴儿发布了紧急含麻疹疫苗接种建议。鉴于 1998 年至 2001 年期间曾爆发过麻疹疫情，当时有 9 名儿童（包括 4 名婴儿）死亡，冲绳县民众对婴儿麻疹的担忧加剧。在 8062 名 6-11 月龄接受含麻疹疫苗（MCV）接种的婴儿中，有 6 名发生疫苗相关麻疹；发病率为每 1000 剂 0.74 例（95%CI 0.27-1.62）。这与一岁时接受首剂常规免疫接种者的发病率（IR 0.60，95%CI 0.20-1.78）相似。在 14 例疫苗相关麻疹病例中，实时逆转录聚合酶链反应（RT-qPCR）检测咽拭子样本阳性率最高（92.9%），其次为尿液（25.0%）和全血（7.7%）样本。此外，1 份经 RT-qPCR 检测为可疑的咽拭子样本，经常规 RT-PCR（RT-PCR）检测为阳性。在疫情期间，尽可能准确和紧急地区分由野生循环病毒引起的类似麻疹症状病例和由疫苗衍生病毒引起的病例至关重要，因为公共卫生应对措施将大不相同。在此次疫情中，没有观察到婴儿死亡，在疫情应对期间接种 MCV 的 6-11 月龄婴儿中也没有观察到严重的疫苗不良反应。因此，我们得出结论，紧急接种 MCV 是有效的，描述麻疹疫情期间疫苗相关麻疹病例的特征将有助于未来的疫情应对工作。
