Right now, we aren’t even close to an answer. Without any results from randomized clinical trials, it is little more than a guessing game at this point.
A French study of HCQ suggested that it had was effective in decreasing the viral load from nasal secretions. When azithromycin was added the magnitude of the effect was larger. At best, this study might give us a clue about how effective HCQ is in reducing transmission since the authors didn’t measure or mention the drug’s impact on the lung. There is absolutely no evidence that HCQ or HCQ/azithromycin would have any effect on seriously ill patients with viral pneumonia. And there is indirect evidence that it did not; otherwise, we’d be hearing about how the drug(s) cured or helped really sick people. There are other problems with this study, but since no impact on lung function was considered it is difficult to conclude that the drugs provided any benefit whatsoever.
And a Chinese study of 30 patients doesn’t prove that HCQ worked. Or that it doesn’t. But the two groups, control and treated, showed no difference in the amount of virus in the throat on day seven, the length of time for the fever to go away. There was an apparent difference in the progression of the infection (determined by x-ray), in the two groups but this means little since 5/15 treated patients got worse vs. 7/15 in the control group. This effect could easily be by chance and nothing to do to the drug. Furthermore, this trial did not include azithromycin, so it cannot be compared to the French trial.
Conclusion: There is nothing encouraging here, at least so far.