(Originally posted as a reply to a dead comment)

While there was some controversy regarding how COVID spreads in the early days (droplets vs aerosol, how many virions you needed to be exposed to to become infected, whether asymptomatic transmission was possible, etc.), most of the details were fairly well understood within a year after the pandemic started. Plus, we were already aware that coronaviruses are capable of spreading via the air and causing mass outbreaks [0], so even at the very beginning I doubt that many experts would have claimed that it was impossible for COVID-19 to cause a pandemic.

However, Ebola has been around for 50 years now [1], so we have a pretty good idea how it works. And every source that I've read says that it spreads exclusively through direct fluid contact with someone who is symptomatic [2] [3] [4] [5], and so does every other virus in the same family [6], so it seems almost impossible for Ebola to cause the same type of worldwide outbreak that COVID-19 did.

(I'm not claiming that Ebola will never spread to North America/Europe, or that an outbreak won't spread to and kill lots of people in Africa, just that it should spread much slower than COVID-19 and that it should be much easier to prevent its transmission.)

[0]: https://en.wikipedia.org/wiki/2002%E2%80%932004_SARS_outbrea...

[1]: https://en.wikipedia.org/wiki/Ebola#History

[2]: https://www.cdc.gov/ebola/causes/index.html#heading-xkphh2xy...

[3]: https://www.who.int/news-room/fact-sheets/detail/ebola-disea...

[4]: https://ukhsa.blog.gov.uk/2026/05/18/what-is-ebola-and-how-d...

[5]: https://www.canada.ca/en/public-health/services/diseases/ebo...

[6]: https://en.wikipedia.org/wiki/Filoviridae