The NIH halted trials of hydroxychloroquine. While the drug did not show significant harm to patients, it did not show any benefit. This illustrates the difficulty of drug trials. To show benefit a test group needs to be large enough (in the thousands in my opinion) and include a control group. The more subtle an effect, the larger the control group needs to be to show a benefit. Also, the control group has to be carefully balanced with the test group to remove as many potential confounding variables as possible. The groups have to have a similar age distribution, similar comorbidities, etc. Some of the earlier studies were either too small, did not contain control groups, or the test group was not well matched to the control group.
More data has come out about the effectiveness of masks and social distancing. A meta-analysis of 172 studies indicated that keeping a distance of 2m from others can reduce your risk of infection up to 5 fold. The study also looked at mask use. Using a mask can reduce your risk of infection and N95 respirators were more effective than surgical or cloth masks. However, all of them reduced the risk of infection to 0.18. Meaning you had a 1 in 5 chance of getting infected if you were around someone if you wore a mask. The study did not look at the effect of the contagious individual wearing a mask although past studies have shown that wearing a mask can reduce transmission up to 80%. If you put all these together, you keep 2 m between you and others, both the infected person and folks in public both wore masks, risk drops to 0.7% if you are in the presence of someone who is ill with COVID-19. A great example of this is the news story relating that two hairstylists who were COVID-19 positive had worked on 140 customers. None of the customers became infected. Both the stylists and the customers were required to wear masks in the salon. So in summary, wear a mask!
Dexamethasone, a cheap to manufacture steroid, has been shown in a large clinical trial to decrease deaths in 1/3 of patients on ventilators, and 1/5 of patients on oxygen. This is great news. COVID-19 kills because it creates a cytokine storm, an overreaction of the immune system in the lungs. The lungs fill with fluid and are damaged. As the damage increases, the patient cannot get enough oxygen, and pretty much suffocates. Dexamethasone prevents this inflammatory response, reducing the damage to the lungs, but still allows the body to fight off the infection.