8-20月龄儿童接种肠道病毒71型灭活疫苗的免疫原性和持久性

Immunogenicity and persistence of immunity from an inactivated enterovirus 71 vaccine administered to 8-20-month-old children

目的观察8-20月龄儿童接种2剂次肠道病毒71型(Enterovirus 71,EV-71)灭活疫苗的免疫原性和持久性。方法于2017年10-12月在上海市静安区招募8-20月龄儿童,按0d、30d程序接种2剂次EV-71疫苗,采集免疫前和免疫后60d、365d、730d血标本,采用细胞病变法测定血清EV-71中和抗体,分析抗体阳转率和几何平均滴度(Geometric mean titer,GMT)。结果受试者EV-71疫苗免疫前EV-71中和抗体阳性率、GMT分别为3.25%(4/123)、1:4.17,免疫后60d、365d、730d抗体阳转率分别为96.15%(100/104)、90.20%(92/102)、90.80%(79/87),GMT分别1:41.76、1:28.44、1:43.41。结论8-20月龄儿童对EV-71疫苗具有良好的免疫原性和2年免疫持久性。

Objective To determine the immunogenicity and persistence of immunity resulting from two doses of an inactivated enterovirus 71(EV-71) vaccine administered to 8-20-month-old children.Methods We recruited 8-20-monthold children from October to December 2017 in Jing’an district of Shanghai.Each child received two doses of EV-71 vaccine with a 30-day interval between the doses.We collected serum samples the day before vaccination and60,365,and 730 days after vaccination;we used a micro-cytopathic method to test for EV-71 neutralizing antibodies and determine seroconversion rates and resulting geometric mean titers(GMT).Results Sero-positivity rate and GMT for EV-71 neutralizing antibody before vaccination were 3.25%(4/123) and 1:4.17.Seroconversion rates at 60,365,and 730 days after vaccination were 96.15%(100/104),90.20%(92/102),and 90.80%(79/87),with GMTs of 1:41.76,1:28.44,and 1:43.41.Conclusion Two doses of EV-71 vaccine administered to 8-20-month-old children had a good immunogenicity profile,with immunity persisting for at least 2 years.