How are Doctors curing coronavirus patients with no vaccine?

Vaccines are never a cure and only work as a preventative. Some things that have no vaccine, but still have cures like bacterial infection. However, Covid-19 has neither treatment nor vaccine. The human body (for most people) can produce antibodies that stop the replication of the virus. However, in an older patient, or someone with a compromised immune system this process takes longer. It becomes a question of, can the body produce the required antibodies before the virus kills the patient. So what doctors can do is provide palliative care. That means treating the symptoms to give the body more time in fighting the virus. This could include IV fluids, fever reducing medications. Often in the case of Covid-19 breathing becomes the biggest threat, so O2, and possibly a ventilator.