There can be a wide range of assumption. Anywhere from "all the people we know about are all that are infected" to "everyone else in the world is already infected".
Regardless, the death tolls kind of speak for themselves. What's more, the increase in death toll too. In Italy alone there are over 4000 dead, with a few hundred more a day now. Italy has a population of 60 million. Extrapolating even the current death count in Italy to the rest of the world, and that's 400k deaths. All indications are that it'll be higher than that uncontrolled.
Maybe people are overreacting. But in this case isn't it better to error on the side of caution? Otherwise by the time we realize we're wrong and millions are dying, what do we do then?
I’ll give you a couple reasons why Italy is the mess it is:
1. Significantly older population
2. Shitty healthcare
For context many years ago, the state of Ohio in the US had more MRI machines than all of Canada combined. It’s very possible that due to budget constraints and other things, they have terrible health infrastructure.
Why do we believe that all nations are equal? I can take a look at the Olympics and notice that isn’t the case. Italians make better cars as compared to the French. So maybe they have terrible elderly healthcare? That seems more likely than “super disease kills only Italians and now comes after Americans”
I already answered this in a sister comment. There are at least 3 candidates (Chloroquine , Remdesivir, Favipiravir ) and they are all unlikely to work.
Follow the article and read the summary, remdesivir was already trialed on a patient in Seattle: "The patient had visited Wuhan, returned to Seattle, began displaying symptoms, and was hospitalized on symptom day 3. By symptom day 8 X-ray showed clear lower respiratory tract viral pneumonia (diagnostic ‘ground glass’) and supplemental oxygen was started. Patient worsened, and intravenous antibiotics were started day 9. Patient worsened (proving viral pneumonia), so attending physicians consulted with FDA then had Gilead rush the experimental drug by air, with intravenous treatment starting day 10. Patient improved in 24 hours, was saved, and has since been discharged"
Importantly, "It did, however, show efficacy against SARS and MERS in vitro" So the drug is promising. Not saying it's a silver bullet but definitely promising.
Vaccines are at least a year away. In order of most to least likely to work:
1. Chloroquine is hepotoxic and since cytokine storms is already one of the way covid19 leads to death there is a lot of question whether chloroquine can actually help (in terms of aggregate effect on CFR).
2. Remdesivir didn't work for ebola (original target) and there is no reason to think it would work for covid19.
3. Favipiravir shows activity against many viruses (SARS-CoV-2 included), but doesn't actually reduce mortality for other viral illnesses (unknown for convid19).
Key to understand, many things show activity with the virus but don't actually improve the disease progression.
Regardless, the death tolls kind of speak for themselves. What's more, the increase in death toll too. In Italy alone there are over 4000 dead, with a few hundred more a day now. Italy has a population of 60 million. Extrapolating even the current death count in Italy to the rest of the world, and that's 400k deaths. All indications are that it'll be higher than that uncontrolled.
Maybe people are overreacting. But in this case isn't it better to error on the side of caution? Otherwise by the time we realize we're wrong and millions are dying, what do we do then?