Antigenic and Genomic Diversity of Human Rotavirus VP4 in Two Consecutive Epidemic Seasons in Mexico

Abstract

In the present investigation we characterized the antigenic diversity of the VP4 and VP7 proteins in 309 and 261 human rotavirus strains isolated during two consecutive epidemic seasons, respectively, in three different regions of Mexico. G3 was found to be the prevalent VP7 serotype during the first year, being superseded by serotype G1 strains during the second season. To antigenically characterize the VP4 protein of the strains isolated, we used five neutralizing monoclonal antibodies (MAbs) which showed specificity for VP4 serotypes P1A, P1B, and P2 in earlier studies. Eight different patterns of reactivity with these MAbs were found, and the prevalence of three of these patterns varied from one season to the next. The P genotype of a subset of 52 samples was determined by PCR. Among the strains characterized as genotype P[4] and P[8] there were three and five different VP4 MAb reactivity patterns, respectively, indicating that the diversity of neutralization epitopes in VP4 is greater than that previously appreciated by the genomic typing methods.

Characterization of rotavirus P genotypes circulating among paediatric inpatients in Northern Brazil

“…In the present investigation, most of the samples were classified as either P1B [4] (50%) or P1A [8] (30%), which are essentially those strains most commonly found worldwide, including Brazil 1,9,17,25 . In our study, however, the relative frequencies of these VP4 genotypes are different from those reported in previous investigations in Brazil, and even elsewhere, where rotavirus strains bearing P1A [8] type-specificity usually predominated over those P1B [4] 9,17 .…”

“…Although several investigations throughout the world have documented the relative frequency and distribution of VP4 genotypes in cases of infantile diarrhoea 1,9,25,30 , studies carried out in Brazil are still scarce 17,32 . In Northern Brazil, for example, the only available data on the occurrence of rotavirus P-types are those relating to strains obtained from children followed-up during a community-based, prospective study carried out from 1983 to 1986 21 .…”

Mortalidad por enfermedad diarreica en menores, antes y después de la introducción de la vacuna contra el rotavirus

“…6,7 Sin embargo, se desconoce el impacto de la vacunación universal en años recientes contra el rotavirus en la mortalidad por EDA en México. Desde la década de 1980, el rotavirus se ha reconocido como el principal enteropatógeno en preescolares sin diarrea (30%), con diarrea (54%) [8][9][10][11] y en los menores de dos años hospitalizados por EDA (28%). 12 La probabilidad de infección por rotavirus se incrementa con la edad, mientras que la probabilidad de EDA y EDA grave disminuye con las infecciones subsecuentes y con la edad.…”

“…13 En México habitualmente se aíslan los serotipos G1, G3, G2, G4 y G9, y P1 y P2, en orden de frecuencia. 9,[12][13][14][15][16][17] Se ha corroborado que en este país la infección por rotavirus ocurre a lo largo del año con mayor frecuencia en invierno en menores de 24 meses de edad 6,17 y que mientras la mortalidad infantil por diarrea ha disminuido en verano, persisten picos de mortalidad por esta causa en invierno. 3 En enero de 2004 las autoridades sanitarias mexicanas aprobaron el uso de la vacuna monovalente de rotavirus humano atenuado (VRH) (Rotarix, GlaxoSmi-thKline) en el territorio nacional y se lanzó al mercado en enero de 2005.…”

Group a Rotaviruses in Children with Gastroenteritis in a Canadian Pediatric Hospital: The Prevaccine Era

“…Furthermore, the intragenotypic heterogeneity raised concerns regarding the ability of the vaccine to neutralize all circulating variants. The existence of antigenic diversity within genotypes has been suggested for both VP4 and VP7 antigens (44)(45)(46). Continued monitoring of the genetic diversity of circulating RVA strains using nucleotide sequencing is, therefore, warranted.…”