Provided is a modified reovirus, a pharmaceutical composition thereof, and a method of treating cancer using the same which not only has an excellent anticancer effect on various cancers, including rare cancers, but can also enhance the effect of cancer immunotherapy agents.

Attenuated G9P[6] rotavirus is disclosed herein. In some embodiments, pharmaceutical compositions are disclosed that include an attenuated G9P[6] rotavirus, or a component thereof. These compositions can be used to induce an immune response, such as a protective immune response, to a rotavirus. The compositions can be used as vaccines, such as for children (infants), for example in a prime boost strategy.