Kashitu-Mujinga Gracia, Makaka-Mutondo Anguy, Matondo-Kuamfumu Meris, Mambu-Mbika Fabrice, Bulabula-Penge Junior, Kabeya-Mampuela Trésor, Nkawa Frida, Wanet-Tayele Grace, Nsunda-Makanzu Bibiche, Nsele-Muntatu Pierre, Kabamba Lusamba, Nkuba-Ndaye Antoine, Cikomola Aimé Mwana Wa Bene, Mukamba-Musenga Elisabeth, Ahuka-Mundeke Steve
Département de Virologie, Institut National de Recherche Biomédicale, Kinshasa 01204, Democratic Republic of the Congo.
Service de Microbiologie, Département de Biologie Médicale, Cliniques Universitaires de Kinshasa, Université de Kinshasa, Kinshasa XI, Democratic Republic of the Congo.
Vaccines (Basel). 2025 Jun 25;13(7):680. doi: 10.3390/vaccines13070680.
Poliomyelitis is a vaccine-preventable disease, with oral poliomyelitis vaccines (OPVs) and injectable poliomyelitis vaccines. In the Democratic Republic of the Congo (DRC), circulating vaccine-derived polioviruses (VDPVs) persist due to intrinsic and extrinsic factors, including the quality of the cold chain, which may make the vaccines less effective. This study's objective was to evaluate the cold chain's quality of OPVs and its effect on the vaccine's viability and potency at different levels in health systems in Kinshasa.
A cross-sectional study was conducted in Kinshasa, collecting OPVs at different levels of the health pyramid. Vaccine viability was assessed by cell culture using a modified World Health Organization (WHO) protocol, and the viral titer was determined using the Karber formula. The vaccine titer was classified as "very good", "good", or "poor" according to the WHO standard's viral titer.
A total of 53 vaccines were collected and analyzed, compressing 38 bivalent oral poliomyelitis (bOPV) vaccines and 15 novel oral poliomyelitis vaccines, type 2 (nOPV2). The viral titer ranged from log10 to log 10 and from log10 to log10 for the nOPV2 and the bOPV, respectively. Of these 53 vaccine samples, 10% of the bOPVs showed viral titers below the recommended WHO threshold (>10 CCID/dose), 100% of the nOPV2 had viral titers within the WHO standards (>10 CCID/dose), and a significant decline in the viral titer was observed for both types of vaccines (nOPV2 and bOPV) as the distribution progressed along the level of the health pyramid.
This study demonstrated that the viral titer of OPV declined from central to peripheral areas in routine and campaign strategies in Kinshasa.
脊髓灰质炎是一种可用疫苗预防的疾病，有口服脊髓灰质炎疫苗（OPV）和注射用脊髓灰质炎疫苗。在刚果民主共和国，由于包括冷链质量在内的内在和外在因素，疫苗衍生脊髓灰质炎病毒（VDPV）持续存在，这可能会使疫苗效果降低。本研究的目的是评估金沙萨卫生系统不同层面OPV的冷链质量及其对疫苗活力和效力的影响。
在金沙萨进行了一项横断面研究，在卫生金字塔的不同层面收集OPV。使用改良的世界卫生组织（WHO）方案通过细胞培养评估疫苗活力，并使用卡尔贝公式测定病毒滴度。根据WHO标准的病毒滴度，将疫苗滴度分为“非常好”、“好”或“差”。
共收集并分析了53种疫苗，其中包括38种二价口服脊髓灰质炎疫苗（bOPV）和15种2型新型口服脊髓灰质炎疫苗（nOPV2）。nOPV2和bOPV的病毒滴度分别在log10至log10和log10至log10之间。在这53个疫苗样本中，10%的bOPV病毒滴度低于WHO推荐阈值（>10 CCID/剂量），100%的nOPV2病毒滴度在WHO标准范围内（>10 CCID/剂量），并且随着疫苗沿卫生金字塔层面分发，两种疫苗（nOPV2和bOPV）的病毒滴度均出现显著下降。
本研究表明，在金沙萨的常规和应急接种策略中，OPV的病毒滴度从中心地区到周边地区呈下降趋势。
