Viruses use genetic material (either DNA or RNA) which makes them difficult to treat because our body’s own cells contain DNA and RNA to make proteins which is why viruses when they enter into the body can replicate so quickly. They can also change their protein markers on their outer coat with time making them have a different structure which makes it difficult for one vaccine to combat a virus. The flu virus has a new vaccine each year because there are new strains of the flu each year since the virus can change the protein markers on its outer protein coat. The coronavirus might be the same way because it is similar to the sars disease in 2004. It may be likely that the outer protein markers on the virus changed making the virus structure different and it being the coronavirus (SARS-CoV-2) rather than sars disease (SARS-CoV-1 ) but the behavior of the two viruses have similar effects on the body even though the coronavirus has been more widespread.

There are currently no vaccines for coronavirus but researchers think that perhaps in a year or 18 months there might be more knowledge on both the sars disease and coronavirus so that a vaccine can be developed

Treatment for Coronavirus Disease (COVID-19) March 12, 2020 healthline.com

Studying how diseases occur due to viruses, bacteria or aging (cancers) is fascinating.