A large donor working with DMI to scale up messaging around handwashing seems like an obvious place to start given that they are plausibly close to that level of cost-effectiveness even ignoring coronavirus, and under optimistic assumptions are significantly better than that.

Fund a study to investigate the use of DIY-masks. Promote their use to at risk population, and fund add campaigns with scientists.

Although Western governments have come out against face masks, Eastern ones (China, Japan, Korea, Taiwan) are strongly in favor of people wearing face masks to protect themselves. There is evidence, that even homemade masks are good at protecting people from respiratory droplets . These could be used if the shortage in surgical masks persist.

Since in the West nobody is promoting this evidence in favour of face masks, this is a potential high impact intervention.

Paying people in Bangladesh 1$ a day to stay home.

Perhaps a Eurovision-style graphic design contest, with modest prizes given to the designers or artists who most memorably communicate the key mitigation tactics of hand-washing, social distancing, surface cleaning, and "flattening the curve." National and regional winners could garner earned media for their victories. The design community seems effective at virally promoting good design, and especially any accolades for a designer's work, so I could see a modest investment going far here.

I would chip in some organizing time and some dollars for a project like this, or another good project someone else thinks up!

Possibly something around domestic violence? China saw a rise in DV during its lockdown.

I could imagine the possibility of spending a month in quarantine with your abuser could inspire a sudden uptick in victims wanting to leave, if there's somewhere for them to go.

My best guess is no, but feel like I should throw this question out there in case anyone can think of plausible candidates.

Can you explain your thinking behind this? My model is that COVID-19 will spread to developing countries before too long, and once there, it will quickly become a much bigger problem than malaria etc. So the highest-impact global health intervention would appear to be "beta testing" of anti-COVID-19 interventions that we think can be transferred to a developing country context.

Anyway, this recent post on far-ultraviolet light looks pretty interesting. I'm pretty optimistic about ideas like this which could use the momentum of COVID-19 to overcome regulatory hurdles etc. and then end up being super valuable for other problems going forward.

Buying new masks can be a bad idea. Though there is an evidence, the problem is limited capacity of stocks. To my understanding, China produce these masks so massively that they can afford selling them to whole population. But, let's say, in US, we have the opposite situation. And massively buying masks can reduce capacity of the healthcare system, which is the main bottleneck in preventing deaths now. There are a lot of articles on this topic, and I didn't review them, but this can be an example. And from my discussion with an MD friend who works in a clinic I got impression that masks could be a huge problem when the healthcare system will be overloaded, as even clinical workers may not have enough protection. So I'm wondering whether we can do something with either reducing the non-targeted consumption of masks (shifting to using hand-made masks?) or with improving distribution/production of masks.

I'm sure funding for hand sanitizer, soap, masks etc in refugee camps would be welcome.

Lobbying for better healthcare/sanitation for prisoners may be effective in certain countries.

Not a funding opportunity, but I think a grassroots effort to employ social norms to enforce social distancing could be effective in countries in early stages where authorities are not enforcing, e.g. The Netherlands, UK, US, etc.

Activists (Student EA's?) could stand with signs in public places asking people non-aggressively to please go home.