Specificity of hemagglutination-inhibition with adenovirus particles of subgroup I and III

Terminal dilution purification of adenovirus prototypes, and the antigenic relationship between types 4, 16 and 14

Two terminal dilution purifications in HEK cells were performed with adenovirus prototypes of types 1 to 7, 12, 16, 19 and 9-15, and one terminal dilution with a freshly isolated type 8 strain. The antisera prepared against viruses after terminal dilution neutralized the original and the purified virus to the same extent, indicating the antigenic purity of the respective prototypes. Cross-reactions in neutralization with other types within the subgroup were also identical. Only the prototype of type 16 (Ch 79) showed a cross-neutralization with type 4, while four type 16 wild strains showed cross-neutralization with type 14, but none with type 4. The prototype (CH 79) is a "prime strain" in relation to the type 16 wild strains.