Acosta C J, Galindo C M, Schellenberg D, Aponte J J, Kahigwa E, Urassa H, Schellenberg J R, Masanja H, Hayes R, Kitua A Y, Lwilla F, Mshinda H, Menendez C, Tanner M, Alonso P L
Unidad de Epidemiologia y Bioestadistica, Hospital Clinic/IDIBAPS, Barcelona, Spain.
Trop Med Int Health. 1999 May;4(5):368-76. doi: 10.1046/j.1365-3156.1999.00406.x.
Malaria control programmes need to protect young children, who bear the brunt of malaria disease and death in Africa. The development of a vaccine is a priority if improved and sustained malaria control is to be achieved. The best use of a vaccine in Africa will be achieved if it can be delivered through the expanded programme of immunization (EPI). We conducted a trial designed to evaluate the efficacy of SPf66 vaccine for malaria control when delivered through the EPI scheme in Tanzania.
The study was a two-arm, double blind, individually randomized placebo controlled trial involving 1207 infants. The primary objective of the trial was to estimate the efficacy of three doses of SPf66 given at 1, 2 and 7 months of age in preventing clinical episodes of malaria. These were documented through a health facility-based passive case detection system.
Among 1207 randomized children, overall compliance for third dose was 91%. SPf66 was safe, immunogenic and did not interfere with the humoral immune responses to EPI vaccines. There were 294 children among SPf66 recipients and 288 among placebo recipients with at least one malaria episode, yielding a vaccine efficacy estimate of 2% (95% CI: -16, 16; P = 0.84).
This has been the first trial of a malaria vaccine among very young infants. It provides information on the safety of peptide vaccines administered at this early age as well as their capacity to induce immune responses without negatively interacting with EPI vaccines. Given the modest protection previously documented in older age groups and the lack of efficacy in younger infants, this vaccine in its current alum-based formulation does not appear to have a role in malaria control in sub-Saharan Africa. The lack of efficacy found in this trial also raises concerns about potential difficulties of inducing protective immune responses against malaria through immunization in infants.
疟疾防控项目需要保护幼儿，因为在非洲，幼儿首当其冲地承受着疟疾疾病和死亡的冲击。若要实现更好且持续的疟疾防控，开发疫苗是当务之急。如果能通过扩大免疫规划（EPI）来接种疫苗，就能在非洲实现疫苗的最佳利用。我们开展了一项试验，旨在评估通过坦桑尼亚的EPI计划接种SPf66疫苗对疟疾防控的效果。
该研究是一项双臂、双盲、个体随机、安慰剂对照试验，涉及1207名婴儿。试验的主要目的是评估在1、2和7月龄时接种三剂SPf66预防疟疾临床发作的效果。这些发作情况通过基于医疗机构的被动病例检测系统记录。
在1207名随机分组的儿童中，第三剂的总体依从率为91%。SPf66安全、具有免疫原性，且不干扰对EPI疫苗的体液免疫反应。SPf66接种组有294名儿童、安慰剂接种组有288名儿童至少出现一次疟疾发作，疫苗效果估计为2%（95%置信区间：-16, 16；P = 0.84）。
这是首次在非常年幼的婴儿中进行疟疾疫苗试验。它提供了关于在此早期年龄接种肽疫苗的安全性信息，以及它们诱导免疫反应而不对EPI疫苗产生负面相互作用的能力。鉴于之前在较大年龄组中记录的保护作用有限，且在年幼婴儿中缺乏效果，这种目前基于明矾配方的疫苗似乎在撒哈拉以南非洲的疟疾防控中没有作用。该试验中发现的缺乏效果也引发了对通过免疫接种在婴儿中诱导针对疟疾的保护性免疫反应的潜在困难的担忧。
