西藏自治区健康人群接种新型冠状病毒肺炎疫苗后特异性IgG抗体调查

Investigation of specific IgG antibody in healthy population after vaccination with COVID-19 vaccine in Xizang Autonomous Region,China

目的了解西藏自治区健康人群在新型冠状病毒肺炎(Coronavirus Disease 2019,COVID-19)灭活疫苗免疫后的新型冠状病毒(2019 novel coronavirus,2019-nCoV)特异性IgG抗体阳性率,评价疫苗免疫效果。方法从西藏自治区6个地级市选择无2019-nCoV感染史并已完成全程2剂次免疫或加强免疫的健康人群作为研究对象,采集血清样本并用化学发光法检测2019-nCoV特异性IgG抗体,分析不同免疫史以及各年龄组接种者的抗体阳性率。结果共计纳入调查对象22255名,2019-nCoV特异性IgG抗体总体阳性率为96.38%。加强免疫人群的抗体阳性率为97.12%,远高于全程免疫人群的88.38%,差异具有统计学意义(χ^(2)=381.11,P<0.001)。不同年龄组间抗体阳性率差异有统计学意义(χ^(2)=138.28,P<0.001),低年龄≤10岁和11~20岁组的抗体阳性率均低于其他年龄组,分别为93.44%和89.03%。除那曲市和≤10岁年龄组外,同地区不同年龄组之间和不同地区相同年龄组之间的不同免疫史人群抗体阳性率差异均具有统计学意义(P<0.05)。结论COVID-19灭活疫苗对西藏自治区健康人群具有良好的免疫效果,加强免疫有助于提高群体特异性IgG抗体阳性率。

Objective To understand the positive rate of 2019 novel coronavirus(2019-nCoV)specific IgG antibody induced by Coronavirus Disease 2019(COVID-19)inactivated vaccine in healthy population in Xizang Autonomous Region,and evaluate the immune effect of the vaccine.Methods Serum samples were collected from COIVD-19 vaccine immunized health population without history of 2019-nCoV infection from six prefecture-level cities in Xizang Autonomous Region.The IgG antibody against 2019-nCoV were tested by chemiluminescence method.Then,the positive rate of IgG antibody was analyzed for different immunization histories and age groups.Results A total of 22255 participants were enrolled in this survey.After full-access(two doses of vaccine)and booster immunization,the overall positive rate of specific IgG antibody against 2019-nCoV was 96.38%.The positive rate of IgG antibody in the booster immunized population was 97.12%,which was much higher than the 88.38%in the full-access immunization population,the difference is statistically significant(χ^(2)=381.11,P<0.001).There was a significant differences in the positive rates of specific IgG antibodies in different age groups(χ^(2)=138.28,P<0.001).Especially in the younger age groups,including less than 10 years old and the 11-20 years age group,the positive rate of specific IgG antibody were 93.44%and 89.03%respectively,which were lower than those in other age groups.Except for Naqu city and the age group≤10 years old,the differences in antibody positivity rates were statistically significant between different age groups in the same region and between the different regions in the same age group for the two populations with different immunization histories(P<0.05).Conclusions The COVID-19 inactivated vaccine showed a good immune effect in the healthy population in Xizang Autonomous Region,and the booster immunization helps to increase the positive rate of specific IgG antibody in healthy population.