Division of Vector-Borne Diseases, Centers for Disease Control and Prevention, Fort Collins, CO, USA.
J Travel Med. 2018 Jan 1;25(1). doi: 10.1093/jtm/tay108.
Few studies have assessed the duration of humoral immunity following yellow fever (YF) vaccination in a non-endemic population. We evaluated seropositivity among US resident travellers based on time post-vaccination.
We identified serum samples from US travellers with YF virus-specific plaque reduction neutralization testing (PRNT) performed at CDC from 1988 to 2016. Analyses were conducted to assess the effect of time since vaccination on neutralizing antibody titer counts.
Among 234 travellers who had neutralizing antibody testing performed on a specimen obtained ≥1 month after vaccination, 13 received multiple YF vaccinations and 221 had one dose of YF vaccine reported. All 13 who received more than one dose of YF vaccine had a positive PRNT regardless of the amount time since most recent vaccination. Among the 221 travellers with one reported dose of YF vaccine, 155 (70%) were vaccinated within 10 years (range 1 month-9 years) and 66 (30%) were vaccinated ≥10 years (range 10-53 years) prior to serum collection. Among the 155 individuals vaccinated, <10 years prior to serum collection, 146 (94%) had a positive PRNT compared with 82% (54/66) of individuals vaccinated ≥10 years prior to serum collection (P = 0.01). Post-vaccination PRNT titers showed a time-dependent decrease. Individuals with immunocompromising conditions were less likely to have a positive PRNT (77%) compared with those who were not immunocompromised (92%; P = 0.04).
Although the percentage of vaccinees with a positive PRNT and antibody titers decreased over time, a single dose of YF vaccine provided long-lasting protection in the majority of US travellers. A booster dose could be considered for certain travellers who are planning travel to a high risk area based on immune competence and time since vaccination.
在非流行地区,很少有研究评估黄热病(YF)疫苗接种后体液免疫的持续时间。我们根据接种后时间评估了美国居民旅行者的血清阳性率。
我们从 1988 年至 2016 年在美国疾病控制与预防中心进行黄热病病毒特异性蚀斑减少中和试验(PRNT)的旅行者血清样本中确定了血清样本。进行了分析,以评估距接种疫苗时间对中和抗体滴度计数的影响。
在 234 名旅行者中,有 13 名接受了多次 YF 疫苗接种,221 名接受了一剂 YF 疫苗接种。所有接受超过一剂 YF 疫苗接种的 13 人,无论最近一次接种疫苗后的时间长短,PRNT 均为阳性。在 221 名接受一剂 YF 疫苗接种的旅行者中,有 155 名(70%)在 10 年内(1 个月至 9 年)接种疫苗,66 名(30%)在血清采集前≥10 年(10 年至 53 年)接种疫苗。在 155 名在采集血清样本前不到 10 年接种疫苗的个体中,有 146 人(94%)的 PRNT 为阳性,而在采集血清样本前≥10 年接种疫苗的个体中,有 82%(54/66)的个体的 PRNT 为阳性(P=0.01)。接种疫苗后的 PRNT 滴度显示出随时间推移而下降的趋势。与未免疫抑制的个体(92%;P=0.04)相比,免疫抑制个体的 PRNT 阳性率较低(77%)。
尽管随着时间的推移,PRNT 和抗体滴度阳性的疫苗接种者比例下降,但单剂 YF 疫苗为大多数美国旅行者提供了长期保护。对于那些根据免疫能力和接种疫苗时间计划前往高风险地区的旅行者,可以考虑加强剂量。