VP7 and VP4 genotypes of rotaviruses cocirculating in Iran, 2015 to 2017: Comparison with cogent sequences of Rotarix and RotaTeq vaccine strains before their use for universal mass vaccination

Abstract

The present study was conducted to analyze the genotypic diversity of circulating species A rotavirus (RVA) strains in Iran and also to investigate comparative analysis between the genotypes of VP4 and VP7 of cocirculating RVA and vaccine strains before the vaccine is introduced in the national immunization program. The G3‐lineage I was found in this study as the most common G genotype which was followed by G9‐lineage III, G1‐lineages I, II, G12‐lineage III, G2‐lineage IV, and G4‐lineage I. Also, P[8]‐lineages III, IV was found as the predominant P genotype which was followed by P[4]‐lineage V, and P[6]‐lineage I. Overally, G3P[8] was determined as the most common combination. Moreover, the analysis of the VP7 antigenic epitopes showed that several amino acid differences existed between circulating Iranian and the vaccine strains. The comparison of genotype G1 of Iranian and vaccine strains (RotaTeq and Rotarix), and genotypes G2, G3, and G4 of Iranian and RotaTeq vaccine strains revealed three to five amino acids differences on the VP7 antigenic epitopes. Furthermore, analyzing of the VP8* epitopes of Iranian P[8] strains indicated that they contained up to 11 and 14 amino acid differences with Rotarix and RotaTeq, respectively. Based on different patterns of amino acid substitutions in circulating and vaccine strains, the emergence of antibody escaping mutants and potentially the decrease of immune protection might ensue in vaccinated children. However, considering the broad cross‐protective activity of RVA vaccines, their efficacy should be monitored after the introduction in Iran.

Genetic characterization of P[8] rotavirus strains circulated in Iran between 2009 and 2017

“…analyses of P[8] sequences from the global RVA database, P[8] clustered into four separate evolutionary lineages: P[8]-lineage I, P[8]-lineage II, P[8]-lineage III, and P[8]-lineage IV 38. In the line with our previous finding,25,39 most of the Iranian strains clustered in P[8]-lineage III, which differed from the vaccination strain lineages (Rotarix TM and RotaTeq TM ), which grouped in P[8]-lineages I and II, respectively. Lineage IV strains, which have also been found in Iranian strains, have recently gained interest because they are now being detected all around the world after initially being discovered in Malawi 40.…”

“…Overall, it has been indicated that the most predominant VP7 genotype was G1 in past years, although some studies sporadically reported the prevalence of the G3, G4, G8, and G9 strains, showing RVA G genotype distributions fluctuated both geographically and temporally in the absence of RVA vaccination 24–31 24,25,30 . As mentioned, the P [8] strain is the main vaccine target included in both RVA vaccines, and also P[8] strain still continues a mostly dominant P genotype in Iran.…”

“…[24][25][26][27][28][29][30][31] Among RVA VP4 genotypes, P[8] has been regularly present and frequently was the predominant strain in most locations of Iran. 24,25,30 As mentioned, the P [8] strain is the main vaccine target included in both RVA vaccines, and also P[8] strain still continues a mostly dominant P genotype in Iran. Therefore, in the prevaccination era, it might be of critical…”

Emergence of equine-like G3 strains as the dominant rotavirus among children under five with diarrhea in Sabah, Malaysia during 2018–2019

“…which would prevent neutralizing antibody activity [49]. Substitution (K238N) was previously identified in Belgian [48], Iranian [50], Russian [51] and Tunisian [52] strains. Amino acid changes at residues 100, 146,148,150,188,190,194,180,183,114,116,133,135,87,88,89 have been shown to cause escape from neutralization with monoclonal antibodies [53].…”

Phylodynamic characteristics of the Russian population of rotavirus А (Reoviridae: Sedoreovirinae: Rotavirus) based on the VP6 gene

“…Многочисленные работы посвящены сравнительному анализу области нейтрализующих эпитопов белков VP7 и VP4 у РВА, изолированных на разных территориях, и вакцинных штаммов RV1 и RV5 [35][36][37]. Однако подобные исследования не проводятся в отношении белка VP6, в связи с чем мы провели сравнение аминокислотного состава области антигенных эпитопов белка VP6 штаммов в составе RV1 и RV5 и ротавирусов, изолированных на территории РФ после 2010 г. Анализ аминокислотного состава в области антигенных эпитопов VP6 указывает на высокую консервативность антигенных детерминант у вакцинных штаммов и штаммов дикого типа, изолированных на территории РФ, несмотря на разницу во времени их выделения.…”