Mitra Monjori, Chowdhury Jaydeep, Basu Surupa, Halder Partha Pratim, Mukherjee Mallar, Karadkhele Archana, Puppalwar Gaurav, Jain Rishi
Institute of Child Health, Kolkata, India.
Medical Affairs Division, Wockhardt Ltd., 1st Floor, West Wing, Wockhardt Global Headquarters, Bandra Kurla Complex, Bandra (East), Mumbai-51, India.
Ther Adv Vaccines Immunother. 2020 Aug 11;8:2515135520937216. doi: 10.1177/2515135520937216. eCollection 2020.
In India, where varicella outbreaks are reported at a younger age, a two-dose vaccine schedule administered at an early age could be highly efficacious in preventing varicella infection. The aim of this study was to evaluate the immunogenicity and safety of live attenuated varicella vaccine (VR 795 Oka strain) in a two-dose, 3 months apart regimen.
Healthy children (⩾ 12 months and ⩽12 years; mean age: 4.4 years) of either sex were included. Geometric mean titers (GMT) were measured at baseline and 28 days post first- and second-dose, and seroprotection rates were measured 28 days post first and second dose. The incidence of breakthrough (BT) infections post vaccination was determined from 42 days post first and second dose of vaccine up to 12 months. Adverse events (AEs) were monitored and recorded throughout the study period.
Of 305 subjects enrolled, 217 were seronegative. The seroconversion rate (a change from a seronegative to a seropositive condition) was 93.3% post first-dose and 100% post two-doses. High levels (9 times) of GMT were reported since post first-dose to post second-dose in children aged 12-18 months, 18-60 months (99.43%); and in and above 60 months (99.02%). The extent of rise of anti-VZV IgG antibody titer post 28 days of first-dose at two-fold, three-fold and four-fold rise was 93.39%, 90.56% and 80.66%, respectively and 100% 4-fold rise post second-dose. A single case, a day after the first-dose of vaccination of mild BT infection, was observed after close contact with a severe case. AEs were mild and none of the serious AEs were related to the study drug.
The two-dose schedule of varicella vaccine was safe and immunogenic when given 3 months apart. However, further comparative studies and follow up for both dosing schedules are needed to validate the advantage of early dosing.
在印度，水痘疫情报告显示发病年龄较小，在幼儿期接种两剂疫苗的接种程序在预防水痘感染方面可能非常有效。本研究的目的是评估减毒活水痘疫苗（VR 795 Oka株）在两剂、间隔3个月接种程序中的免疫原性和安全性。
纳入年龄在12个月及以上、12岁及以下（平均年龄：4.4岁）的健康儿童，男女不限。在基线、首剂和第二剂接种后28天测量几何平均滴度（GMT），在首剂和第二剂接种后28天测量血清保护率。从首剂和第二剂疫苗接种后42天至12个月确定接种疫苗后突破性（BT）感染的发生率。在整个研究期间监测并记录不良事件（AE）。
在纳入的305名受试者中，217名血清学阴性。首剂接种后的血清转化率（从血清学阴性转变为血清学阳性）为93.3%，两剂接种后为100%。在12 - 18个月、18 - 60个月（99.43%）以及60个月及以上（99.02%）的儿童中，自首剂接种后至第二剂接种后报告了高水平（9倍）的GMT。首剂接种28天后抗VZV IgG抗体滴度呈两倍、三倍和四倍升高的程度分别为93.39%、90.56%和80.66%，第二剂接种后四倍升高的比例为100%。在与一例重症病例密切接触后，观察到1例在首剂接种疫苗后一天发生的轻度BT感染病例。不良事件为轻度，且无严重不良事件与研究药物相关。
水痘疫苗两剂接种程序间隔3个月接种时安全且具有免疫原性。然而，需要进一步的对比研究以及对两种接种程序进行随访，以验证早期接种的优势。
