ABSTRACT
Unlike conventional vaccines to infectious diseases, which stimulate the immune system to respond specifically to nonself, dangerous, ‘foreign’ microbial antigens, the challenge of developing effective cancer vaccines lies in the ability of the immune system to recognize and respond to self or ‘altered self’, essentially non-dangerous antigens. Apart from virally induced tumours, most tumours express antigens that fit more with a self/altered-self paradigm than with the non-self paradigm antigens of pathogens.1 To answer the most frequently asked question about whether immunity to cancer exists at all, one needs to analyse the occurrence of spontaneous regression in certain cancers and the existence of correlation between tumour prognosis and patient survival with intra-tumoral inflammatory cell infiltrations.
