How’d We Get a COVID-19 Vaccine so Fast but None for HIV and Cancer? Advertisement Social media posts that make misleading comparisons undermine the science behind the COVID-19 vaccine. Advertisement Remember the wise advice about comparing apples to oranges? (Hint: Don’t do it.) Well, it’s especially true when you’re contrasting the development of a vaccine for COVID-19 with a vaccine against HIV, cancer or the common cold. In other words, just because scientists haven’t been able to develop a vaccine against HIV after several decades, doesn’t mean researchers need as lon...