Cancer and the common cold are groups of diseases classified under one umbrella term, not specific diseases that you could prevent with one single vaccine or treatment.

HIV is vastly more complex, mutates quickly and is different from other viruses because it attacks the immune system itself, hence the name.

The Pfizer COVID-19 vaccine was not developed in a year, it is a SARS vaccine that started development after the 2012 outbreak, which could be adjusted for COVID since the two are similar.