JID：儿童感染HIV不增加免疫缺陷相关疫苗源脊髓灰质炎风险

尽管口服脊髓灰质炎疫苗（OPV）能够有效预防脊髓灰质炎的发生，但是持续使用该疫苗也导致了疫苗源脊髓灰质炎（VDPV）的发生，影响了根除脊髓灰质炎项目的进行。VDPV与亲代的OPV毒株在序列上只有1%-15%的差异，但是前者的病毒复制周期延长并超过1年。一般来说，接种OPV的儿童能在几周内将病毒消灭，但是初始体液免疫缺陷的个体需要更长的时间来消灭病毒，甚至有一例超过了20年，这就有助于免疫缺陷相关VDPV（iVDPV）的形成。

围产期感染HIV与体液和细胞免疫缺陷相关。在围产期感染HIV的儿童通常患有多克隆高γ丙球蛋白血症，而此病与减少针对特殊抗原的抗体反应有关。另外，在2百万感染HIV的儿童中，大约有90%居住在非洲，而在非洲，无论是否感染HIV，都主要以OPV作为接种疫苗。感染HIV的儿童消灭脊髓灰质炎病毒时间的延长影响了脊髓灰质炎根除效果。为了确认围产期感染HIV的儿童是否为iVDPV的来源并进一步评估HIV感染儿童对OPV的体液和细胞免疫反应，来自美国的东部弗吉尼亚州医学院的Stephanie B. Troy和同事进行了一项研究，该研究结果在线发表于2013年5月14日的Journal of Infectious Diseases上。研究发现感染HIV与脊髓灰质炎病毒消除时间的延长无关。

该前瞻性研究在多个时间点收集了来自津巴布韦婴儿的粪便和血样本。从粪便中提取核酸，并采用实时PCR分析OPV血清型。

在825个粪便样本中，有285样本来自92位HIV感染儿童，而540个样本来于251位未感染HIV的儿童。在两组中，接种0至2次OPV的脊髓灰质炎病毒消失时间相似，而接种多于或等于3次OPV疫苗的HIV感染孩子消灭病毒时间较长，尤其是在一次使用OPV的42天内，而这与血清转化状态无关。HIV感染与脊髓灰质炎病毒消除时间的延长或持续无关。此外，HIV感染与低血清转化率有密切的联系。

研究发现，HIV感染降低了对OPV的粘膜和体液免疫反应能力，但是与形成iVDPV所需的病毒消除时间的延长无关。

Vaccine Poliovirus Shedding and Immune Response to Oral Polio Vaccine in HIV-Infected and -Uninfected Zimbabwean Infants.
Background
With prolonged replication, attenuated polioviruses used in oral polio vaccine (OPV) can mutate into vaccine-derived poliovirus (VDPV) and cause poliomyelitis outbreaks. Individuals with primary humoral immunodeficiencies can become chronically infected with vaccine poliovirus, allowing it to mutate into immunodeficiency-associated VDPV (iVDPV). It is unclear if children perinatally infected with the human immunodeficiency virus (HIV), who have humoral as well as cellular immunodeficiencies, might be sources of iVDPV.
Methods
We conducted a prospective study collecting stool and blood samples at multiple time points from Zimbabwean infants receiving OPV according to the national schedule. Nucleic acid extracted from stool was analyzed by real-time polymerase chain reaction for OPV serotypes.
Results
We analyzed 825 stool samples: 285 samples from 92 HIV-infected children and 540 from 251 HIV-uninfected children. Poliovirus shedding was similar after 0-2 OPV doses but significantly higher in the HIV-infected versus uninfected children after ≥3 OPV doses, particularly within 42 days of an OPV dose, independent of seroconversion status. HIV infection was not associated with prolonged or persistent poliovirus shedding. HIV infection was associated with significantly lower polio seroconversion rates.
Conclusions
HIV infection is associated with decreased mucosal and humoral immune responses to OPV but not the prolonged viral shedding required to form iVDPV.