Hospital del Niño, Panama City, Panama; Cevaxin, Avenida Mexico Calle 33, Local 4, Panama City, Panama; Sistema Nacional de Investigación, Senacyt, Panama.
Cevaxin, Avenida Mexico Calle 33, Local 4, Panama City, Panama.
Vaccine. 2022 Sep 22;40(40):5835-5841. doi: 10.1016/j.vaccine.2022.06.084. Epub 2022 Sep 3.
To meet the demand for effective and affordable inactivated polio vaccines (IPVs), a reduced dose, aluminium hydroxide (Al(OH))-adjuvanted IPV vaccine was developed (IPV-Al, Picovax®) and evaluated in clinical trials. The present trial is an extension of two previous trials (a primary and a booster trial). The aim was to evaluate the persistence of seroprotective antibodies (poliovirus type-specific antibody titre ≥ 8) in 4-year-old children who previously received IPV-Al as primary and booster vaccine doses and to determine the potential booster response and safety profile of an additional dose of IPV-Al.
Children participating in the two previous trials were invited to receive one additional dose of IPV-Al at 4 years of age (2.5 years after the booster dose) and to have their blood samples collected to measure the pre- and post-vaccination antibody titres. Systemic adverse events (AEs) and local reactogenicity were recorded.
At study entry, the seroprotection rates were 89.2%, 100% and 91.1% against poliovirus type 1, 2 and 3, respectively. The additional vaccination with IPV-Al boosted the level of poliovirus type 1, 2 and 3 antibodies to above the seroprotection threshold for all but one subject, i.e., 99.4% for type 1 and 100% for types 2 and 3. The additional dose induced a robust booster response of a 26.3-, 13.9- and 30.9-fold increase in titre for poliovirus types 1, 2 and 3, respectively. The vaccine was well tolerated, with only mild and transient AEs reported.
The present trial demonstrated that the primary vaccination with an aluminium-adjuvanted reduced dose IPV induced a persistent immune memory as evidenced by the robust anamnestic response when the subjects were re-exposed to the antigen 2.5 years after the last dose. Thus, the IPV-Al is an efficient and safe addition to increase the availability of inactivated polio vaccines globally. (ClinicalTrials.gov reg no. NCT04448132).
为满足有效且负担得起的灭活脊灰疫苗（IPV）需求，开发了一种低剂量、含氢氧化铝（Al(OH))佐剂的 IPV 疫苗（IPV-Al，Picovax®），并在临床试验中进行了评估。本试验是两项先前试验（初级和加强免疫试验）的扩展。目的是评估先前接受过 IPV-Al 作为初级和加强免疫疫苗剂量的 4 岁儿童体内脊灰病毒保护性抗体（脊灰病毒血清型特异性抗体滴度≥8）的持久性，并确定额外剂量 IPV-Al 的潜在加强免疫应答和安全性特征。
邀请参加两项先前试验的儿童在 4 岁时（加强免疫后 2.5 年）接受一剂额外的 IPV-Al，并采集血样以测量接种前后的抗体滴度。记录全身不良事件（AE）和局部反应性。
入组时，1 型、2 型和 3 型脊灰病毒的血清保护率分别为 89.2%、100%和 91.1%。除一名儿童外，其余儿童接受 IPV-Al 加强免疫后，1 型、2 型和 3 型脊灰病毒抗体水平均提高到保护阈值以上，即 1 型为 99.4%，2 型和 3 型均为 100%。加强免疫诱导了针对脊灰病毒 1 型、2 型和 3 型的 26.3 倍、13.9 倍和 30.9 倍的强烈加强免疫应答。疫苗具有良好的耐受性，仅报告了轻度和短暂的不良事件。
本试验表明，铝佐剂低剂量 IPV 的初次免疫接种诱导了持久的免疫记忆，当受试者在最后一剂后 2.5 年再次接触抗原时，产生了强烈的回忆反应。因此，IPV-Al 是一种有效且安全的补充，可增加全球灭活脊灰疫苗的供应。（ClinicalTrials.gov 注册号：NCT04448132）。
