Isn't the point of masks to stop the wearer from spreading the virus? This study is about wearers contracting the virus.
Sort of. I've heard many health experts claim it protects the wearer too. Also, there are not trials to test if masks stop the wearer from spreading and there probably never will be as it would require them to have contagious participants going out in public like normal and infected other people to get results. So, we will never have controlled studies that support or don't support the idea that masks help prevent wearers from spreading the virus.
So, we are left with "trusting the experts". The problem being that there are experts on both sides of the aisle. Here are explanations for both sides from what I've seen:
Masks work:
-Even cloth and surgical masks block droplets and can catch some aerosolized particles with in their fibers and with static electricity.
-Even if they are only 20% effective, it's still better than nothing.
Masks don't work:
-The general public doesn't know how to handle and dispose of them properly.
-Cloth and surgical masks don't block aerosolized particles.
-Even when masks block droplets, unless you dispose of it quickly, the droplets evaporate and viral particles become aerosolized anyway.
-The pressure from sneezing or coughing into a mask can cause droplets to "break up" upon contacting the mask and aerosolize into smaller droplets and viral particles. The virus might be more contagious in the aerosolized form since another person can jut breathe it in, and it goes directly to the lungs. If someone sneezes and the droplet goes straight to the ground, it won't be aerosolized. In that case, hand hygiene is very effective.
-N95 masks work, but need to be handled, worn and disposed of properly. Should only be used for short durations and never re-used. There will never be enough supply for the whole population to use these effectively.
-There are legitimate concerns with bacterial infections from people wearing the same masks for too long and re-using the same mask over and over. You have a moist mask just sitting there growing bacteria day after day.
If there are other explanations either way I'd genuinely like to know what they are. Those are just the ones I can think of off the top of my head.
Also, looking at data comparing places that have mask mandates to places that don't, there doesn't seem to be any correlation. You can pick and choose two places to fit a narrative, but overall, there doesn't seem to be a trend.
So when the CDC director claimed that wearing a mask is better than a vaccine, either he was lying, or the vaccines are going to suck.