The present invention relates to novel adenovirus strains with an improved seroprevalence. In one aspect, the present invention relates to isolated polypeptides of adenoviral capsid proteins such as hexon, penton and fiber protein and fragments thereof and polynucleotides encoding the same. Also provided is a vector comprising the isolated polynucleotide according to the invention and adenoviruses comprising the isolated polynucleotides or polypeptides according to the invention and a pharmaceutical composition comprising said vector, adenovirus, polypeptide and/or polynucleotide. The invention also relates to the use of the isolated polynucleotides, the isolated polypeptides, the vector, the adenoviruses and/or the pharmaceutical composition for the therapy or prophylaxis of a disease.