Bill & Melinda Gates Foundation, Seattle, Washington, USA.
Biostatistical Consulting, Washington, USA.
J Infect Dis. 2021 Jan 4;223(1):119-127. doi: 10.1093/infdis/jiaa390.
Understanding immunogenicity and safety of monovalent type 2 oral poliovirus vaccine (mOPV2) in inactivated poliovirus vaccine (IPV)-immunized children is of major importance in informing global policy to control circulating vaccine-derived poliovirus outbreaks.
In this open-label, phase 4 study (NCT02582255) in 100 IPV-vaccinated Lithuanian 1-5-year-olds, we measured humoral and intestinal type 2 polio neutralizing antibodies before and 28 days after 1 or 2 mOPV2 doses given 28 days apart and measured stool viral shedding after each dose. Parents recorded solicited adverse events (AEs) for 7 days after each dose and unsolicited AEs for 6 weeks after vaccination.
After 1 mOPV2 challenge, the type 2 seroprotection rate increased from 98% to 100%. Approximately 28 days after mOPV2 challenge 34 of 68 children (50%; 95% confidence interval, 38%-62%) were shedding virus; 9 of 37 (24%; 12%-41%) were shedding 28 days after a second challenge. Before challenge, type 2 intestinal immunity was undetectable in IPV-primed children, but 28 of 87 (32%) had intestinal neutralizing titers ≥32 after 1 mOPV2 dose. No vaccine-related serious or severe AEs were reported.
High viral excretion after mOPV2 among exclusively IPV-vaccinated children was substantially lower after a subsequent dose, indicating induction of intestinal immunity against type 2 poliovirus.
了解单价 2 型口服脊髓灰质炎疫苗（mOPV2）在灭活脊髓灰质炎疫苗（IPV）免疫儿童中的免疫原性和安全性对于制定控制循环疫苗衍生脊髓灰质炎病毒暴发的全球政策具有重要意义。
在这项在 100 名接受过 IPV 接种的立陶宛 1-5 岁儿童中进行的开放性、4 期研究（NCT02582255）中，我们在 28 天间隔接受 1 或 2 剂 mOPV2 之前和之后测量了血清中和抗体，并在每次接种后测量粪便中的病毒脱落情况。父母在每次接种后 7 天记录有症状的不良事件（AE），在接种后 6 周记录无症状的 AE。
在接受 1 剂 mOPV2 挑战后，2 型血清保护率从 98%增加到 100%。在 mOPV2 挑战后约 28 天，68 名儿童中有 34 名（50%；95%置信区间，38%-62%）出现病毒脱落；37 名儿童中有 9 名（24%；12%-41%）在第二次挑战后 28 天出现病毒脱落。在挑战前，IPV 接种的儿童中无法检测到 2 型肠道免疫，但在接受 1 剂 mOPV2 后，87 名儿童中有 28 名（32%）的肠道中和滴度≥32。没有报告与疫苗相关的严重或严重不良事件。
在完全接受 IPV 接种的儿童中，mOPV2 接种后病毒大量排出的情况在随后的剂量后明显减少，表明诱导了对 2 型脊髓灰质炎病毒的肠道免疫。
