The first cells it was shown to replicate in were primary mouse embryo cell cultures, but these cultures had to be freshly explanted.

The mumps virus strains were developed in embryonic hens' eggs and chick embryo cell cultures.

For example, in the case of mumps and measles viruses, the virus strains were grown in embryonated hens' eggs and chick embryo cell cultures.

The outcome of the experiment was expected to help the understanding of early embryo cell development which would provide an insight into the possibilities of human reproduction in space.

Testing on human embryo cells, he worked to overturn these theories and experimented with the vaccine which works by tricking the body into producing antibodies.