African swine fever virus (ASFV) causes a lethal haemorrhagic disease in domestic pigs and wild boar that is now prevalent worldwide. Genetically and immunologically distinct viruses are circulating globally, with genotype II ASFV present across Asia, Africa and Europe, genotype I ASFV present in Western Africa and China and genotype IX in Eastern Africa. A hybrid recombinant between genotypes I and II emerged in China in 2021 and has since spread across Eastern Asia. Modified live virus vaccines targeting genotype II have been licensed in Vietnam but have safety concerns and do not protect against the novel hybrid recombinant.  We have demonstrated protection from severe disease caused by genotype I ASFV with a pool of adenovirus vectored antigens that induce virus specific CD8 responses, but not CD4 responses. To improve protection, new CD4 antigens were selected by analysing T-cell responses from pigs previously immunised with different pools of vectored ASFV genes. Four additional ASFV genes were incorporated into our immunization model and led to significant improvements in both CD4 and CD8 virus-specific responses, as well as a significant improvement in clinical outcome after challenge.  A ten-antigen vaccine would pose a significant cost barrier to implementation and so immune response parameters were used to try and reduce the complexity of the vaccine. The protective capacity of the vaccine was also tested against the genotype I/II hybrid-recombinant. These data will drive development of safe and effective vaccines and have utility as a model for protective immune responses.