Assessing the Intestinal and Humoral Immunity of Sequential Schedules of Inactivated Poliovirus Vaccine and Bivalent Oral Poliovirus Vaccine for Routine Childhood Immunization in Bangladesh
试验速览
- 阶段
- 4 期
- 状态
- 已完成
- 入组人数
- 456
- 试验地点
- 1
- 主要终点
- Change in type 1, 2 and 3 poliovirus antibody responses prior to administration of poliovirus vaccinations compared to after completion of poliovirus vaccinations.
研究概览
简要总结
This is a phase IV open-label randomized clinical trial that will compare intestinal and humoral immunity in infants receiving inactivated poliovirus vaccine (IPV) and two or three doses of bivalent oral poliovirus vaccine (bOPV).
详细描述
The goal of polio vaccination is to protect the individual from paralytic disease (humoral immunity) and to prevent transmission of poliovirus (intestinal immunity). Inactivated poliovirus vaccine (IPV) induces humoral (systemic) immunity to all three types of poliovirus (1, 2 and 3), protecting individuals from developing paralytic polio when exposed to wild type poliovirus. However, it induces little intestinal immunity. Intestinal immunity inhibits poliovirus replication thereby reducing the quantity and duration of poliovirus excretion in stool. This is critical in preventing the spread of poliovirus to others.
Oral polio vaccines are live attenuated vaccines and trivalent OPV (tOPV) is a mixture of poliovirus strains type 1, 2 and 3. Like IPV, OPV induces humoral immunity and is more effective than IPV at inducing intestinal immunity. In most developing countries, routine childhood immunization for poliovirus consists of three doses of tOPV at 6, 10 and 14 weeks of age and may also include a birth dose of tOPV.
An important limitation is that the vaccine virus in OPV can mutate and acquire neurovirulence causing paralysis either due to vaccine-associated paralytic polio (VAPP) or due to circulating vaccine-derived polioviruses (cVDPVs), in which the attenuated vaccine virus not only acquires the ability to cause paralysis but can also circulate similarly to wild poliovirus (WPV). The potential of vaccine virus to acquire neurovirulence and cause paralytic poliomyelitis is incompatible with eradication of polio. Therefore, polio eradication will require eventual cessation of all OPVs.
The last case of WPV type 2 was reported in 1999 in India. Type 2 vaccine virus in tOPV is most likely to cause cVDPVs and over 80% of cVDPVs over the past decade have been cVDPV2. Of the estimated 250-500 annual VAPP cases, almost 40% are due to type 2. Thus, with the eradication of WPV2 it is imperative to prioritize removal of type 2 containing OPV.
The licensing and availability of bOPV containing type 1 and 3 offers the option of an OPV that does not contain OPV2. In April 2013, the Strategic Advisory Group of Experts on Immunization (SAGE) recommended phased cessation of OPVs starting with the switch from tOPV to bOPV. After the switch, bOPV is expected to be administered at 6, 10 and 14 weeks of age, the typical routine poliovirus immunization schedule in developing countries for tOPV. Additionally, at least one dose of IPV was recommended to prevent rapid rise in type 2 susceptibility in the birth cohorts born after the switch to bOPV.
研究设计
- 研究类型
- Interventional
- 分配方式
- Randomized
- 干预模型
- Parallel
- 主要目的
- Prevention
- 盲法
- None
入排标准
- 年龄范围
- 6 Weeks 至 6 Weeks（Child）
- 性别
- All
- 接受健康志愿者
- 是
入选标准
- •Healthy infants 6 weeks of age (range: 42-48 days).
- •Parents that consent for participation in the full length of the study.
- •Parents that are able to understand and comply with planned study procedures.
排除标准
- •Parents and infants who are unable to participate in the full length of the study.
- •A diagnosis or suspicion of immunodeficiency disorder either in the infant or in an immediate family member.
- •A diagnosis or suspicion of bleeding disorder that would contraindicate parenteral administration of IPV or collection of blood by venipuncture.
- •Acute diarrhea, infection or illness at the time of enrollment (6 weeks of age) that would require infant's admission to a hospital or would contraindicate provision of OPV per country guidelines.
- •Acute vomiting and intolerance to liquids within 24 hours before the enrollment visit (6 weeks of age).
- •Receipt of any polio vaccine (OPV or IPV) before enrollment based upon documentation or parental recall.
- •Known allergy/sensitivity or reaction to polio vaccine or contents of polio vaccine.
- •Infants from multiple births. Infants from multiple births will be excluded to reduce the potential for contact transmission of vaccine poliovirus to siblings. The infant(s) from a multiple birth who is/are not enrolled would be likely to receive routine immunization and transmit vaccine poliovirus to the enrolled infant.
- •Infants from premature births (<37 weeks of gestation).
结局指标
主要结局
Change in type 1, 2 and 3 poliovirus antibody responses prior to administration of poliovirus vaccinations compared to after completion of poliovirus vaccinations.
时间窗: 12 weeks
Change in type 1 and 3 excretion of vaccine poliovirus particles in stool one week after administration of the bOPV challenge dose.
时间窗: One week
次要结局
- Change in type 1 and 3 excretion of vaccine poliovirus in stool two weeks after administration of the bOPV challenge dose at 18 weeks of age.(Two weeks)