Department of Biosciences, COMSATS University (CUI), Islamabad, Pakistan.
Front Immunol. 2020 Oct 2;11:562282. doi: 10.3389/fimmu.2020.562282. eCollection 2020.
Group A rotavirus (RVA) is the leading cause of severe childhood diarrhea globally, even with all effective interventions, particularly in developing countries. Among the diverse genotypes of RVA, G1P[8] is a common genotype that has continued to pervade around the world, including Pakistan. Two universally accepted rotavirus vaccines-Rotarix™ and RotaTeq™ contain the genotype G1P[8]. The current work was aimed at identifying differences between antigenic epitopes of Pakistan's G1P[8] strains and those of the two licensed vaccines. We sequenced 6 G1P[8] rotavirus strains previously reported in Rawalpindi, Islamabad, Pakistan in 2015 and 2016 for their outer capsid genes (VP7 and VP4). Phylogenetic analysis was then conducted in order to classify their specific lineages and to detect their association with strains isolated throughout world. Compared with the Rotarix™ and RotaTeq™ vaccine strains (G1-lineage II, P[8]-lineage III), our study G1-lineage I, P[8]-lineage IV strains showed 3 and 5 variations in the VP7 epitopes, respectively, and 13 and 11 variations in the VP4 epitopes, respectively. The G1 lineage II strains showed no single amino acid change compared to Rotarix™ (lineage II), but exhibited changes at 2 positions compared to RotaTeq™ (lineage III). So, this has been proposed that these G1 strains exist in our natural setting, or that they may have been introduced in Pakistan from other countries of the world. The distinct P[8]-lineage IV (OP354-like) strains showed twelve and thirteen amino acid variations, with Rotarix™ and RotaTeq™ (lineages II and III) strains, respectively. Such findings have shown that the VP4-P[8] component of the G1P[8] strains circulating in Pakistan differs considerably from that of the vaccine viruses compared to that of the VP7-G1. To monitor the long-term effects of vaccines on the emergence of G1P[8] strains with different lineages, routine and successful monitoring of these strains will be crucial.
A 组轮状病毒（RVA）是全球导致严重儿童腹泻的主要原因，即使采取了所有有效的干预措施，特别是在发展中国家。在 RVA 的多种基因型中，G1P[8]是一种常见的基因型，它继续在世界各地流行，包括巴基斯坦。两种广泛接受的轮状病毒疫苗——Rotarix™ 和 RotaTeq™ 都含有基因型 G1P[8]。目前的工作旨在确定巴基斯坦 G1P[8]株与两种许可疫苗的抗原表位之间的差异。我们对 2015 年和 2016 年在巴基斯坦拉瓦尔品第和伊斯兰堡报告的 6 株 G1P[8]轮状病毒株的外壳基因（VP7 和 VP4）进行了测序。然后进行了系统发育分析，以便对其特定谱系进行分类，并检测其与世界各地分离株的关联。与 Rotarix™ 和 RotaTeq™ 疫苗株（G1 谱系 II，P[8]-谱系 III）相比，我们的研究 G1 谱系 I，P[8]-谱系 IV 株在 VP7 表位分别显示 3 和 5 个变异，在 VP4 表位分别显示 13 和 11 个变异。与 Rotarix™（谱系 II）相比，G1 谱系 II 株没有单个氨基酸变化，但与 RotaTeq™（谱系 III）相比，有 2 个位置发生了变化。因此，有人提出这些 G1 株存在于我们的自然环境中，或者它们可能是从世界其他国家引入巴基斯坦的。独特的 P[8]-谱系 IV（OP354 样）株在 VP4-P[8]成分方面与 Rotarix™ 和 RotaTeq™（谱系 II 和 III）株分别显示 12 和 13 个氨基酸变异。这些发现表明，与 VP7-G1 相比，在巴基斯坦流行的 G1P[8]株的 VP4-P[8]成分与疫苗病毒有很大的不同。为了监测不同谱系 G1P[8]株疫苗的长期效果，对这些株的常规和成功监测将至关重要。
