V Moresco1, N A Damazo1, C R M Barardi1. 1. Laboratório de Virologia Aplicada, Departamento de Microbiologia, Imunologia e Parasitologia, Centro de Ciências Biológicas, Universidade Federal de Santa Catarina, Florianópolis, Santa Catarina State, Brazil.
Abstract
AIMS: To evaluate the thermal and length of stability of the Rotaviruses (RV) vaccine (RotaTeq) in the aquatic environment. METHODS AND RESULTS: Surface freshwater, brackish and drinking water were spiked with RV vaccine strain and stored at 22 and 4°C. The virus infectivity and genome persistence were evaluated by plaque assay and RT-qPCR, respectively, up to 180 days. Infectious RV vaccine particles showed to be less stable in the brackish water matrix than in surface and drinking water either at 22 or 4°C. The estimated T90 values obtained by the linear regression model were 18, 55 and 59 days, respectively for brackish, surface and drinking water stored at 22°C and 68, 154 and 240 days at 4°C. As expected, the genome persistence showed to be less affected by length and temperature of storage in all the matrices evaluated. CONCLUSIONS: The evidence of high stability of the RV vaccine in water matrices reinforces the importance for surveillance of RV vaccines strains in the environment regarding the potential occurrence of unexpected infections and virus genomic reassortments. SIGNIFICANCE AND IMPACT OF THE STUDY: The presence of reassortants and the shedding of the live attenuated vaccine strains after vaccination can compromise the vaccine safety by introducing new viral variants in the environment.
AIMS: To evaluate the thermal and length of stability of the Rotaviruses (RV) vaccine (RotaTeq) in the aquatic environment. METHODS AND RESULTS: Surface freshwater, brackish and drinking water were spiked with RV vaccine strain and stored at 22 and 4°C. The virus infectivity and genome persistence were evaluated by plaque assay and RT-qPCR, respectively, up to 180 days. Infectious RV vaccine particles showed to be less stable in the brackish water matrix than in surface and drinking water either at 22 or 4°C. The estimated T90 values obtained by the linear regression model were 18, 55 and 59 days, respectively for brackish, surface and drinking water stored at 22°C and 68, 154 and 240 days at 4°C. As expected, the genome persistence showed to be less affected by length and temperature of storage in all the matrices evaluated. CONCLUSIONS: The evidence of high stability of the RV vaccine in water matrices reinforces the importance for surveillance of RV vaccines strains in the environment regarding the potential occurrence of unexpected infections and virus genomic reassortments. SIGNIFICANCE AND IMPACT OF THE STUDY: The presence of reassortants and the shedding of the live attenuated vaccine strains after vaccination can compromise the vaccine safety by introducing new viral variants in the environment.