[Predominance of G9 rotavirus in Valencia and Castellón between 2005 and 2007]

[What have we learnt about rotavirus in Spain in the last 10 years?]

INTRODUCTION

Vaccines against rotavirus (RV) have been available in Spain since 2006, but they are neither recommended nor financed by the National Health System. Nevertheless, through recommendations of the Spanish Association of Paediatrics vaccination has achieved intermediate coverage.

MATERIAL AND METHODS

A systematic literature review was performed on studies carried out in Spain in the last 12 years (2006-2018) on RV infection and vaccination.

RESULTS

A total of 43 studies were identified that met the inclusion criteria. The disease burden in children less than 5 years in the Primary Care setting ranged from 15 to 19 cases per 1,000 children, and between 120 and 480 cases per 100,000 in the hospital setting, which has a significant economic and social impact. Vaccines against RV have shown an effectiveness of between 83% and 96%, and an impact of up to 70% in reducing hospital admissions, which is dependent on the achieved vaccine coverage. New research lines are identified, such as the role of the rotavirus vaccine and protection against seizures or the impact on the gut microbiota.

CONCLUSIONS

The current available information supports the significant burden of rotavirus disease in Spain and the high effectiveness of the available vaccines. This evidence should allow for an updated re-evaluation of the national recommendations on rotavirus vaccination.

Review of global rotavirus strain prevalence data from six years post vaccine licensure surveillance: is there evidence of strain selection from vaccine pressure?

Comprehensive reviews of pre licensure rotavirus strain prevalence data indicated the global importance of six rotavirus genotypes, G1P[8], G2P[4], G3P[8], G4P[8], G9P[8] and G12P[8]. Since 2006, two vaccines, the monovalent Rotarix (RV1) and the pentavalent RotaTeq (RV5) have been available in over 100 countries worldwide. Of these, 60 countries have already introduced either RV1 or RV5 in their national immunization programs. Post licensure vaccine effectiveness is closely monitored worldwide. This review aimed at describing the global changes in rotavirus strain prevalence over time. The genotype distribution of the nearly 47,000 strains that were characterized during 2007-2012 showed similar picture to that seen in the preceding period. An intriguing finding was the transient predominance of heterotypic strains, mainly in countries using RV1. Unusual and novel antigen combinations continue to emerge, including some causing local outbreaks, even in vaccinated populations. In addition, vaccine strains have been found in both vaccinated infants and their contacts and there is evidence for genetic interaction between vaccine and wild-type strains. In conclusion, the post-vaccine introduction strain prevalence data do not show any consistent pattern indicative of selection pressure resulting from vaccine use, although the increased detection rate of heterotypic G2P[4] strains in some countries following RV1 vaccination is unusual and this issue requires further monitoring.