Here's why San Diego Comic-Con could be cancelled in 2020 and 2021. It's no secret the coronavirus pandemic has had an unprecedented impact on the entertainment industry, forcing studios to reschedule their upcoming films and shut down projects in the middle of production. Outside of upcoming movies and TV shows, multiple industry conventions and events like SXSW and WonderCon have either been cancelled or postponed as part of the efforts to practice social distancing and help flatten the curve. With non-essential businesses (including movie theaters) closed, massive gatherings in convention centers can't happen right now.
As the list of affected events and conventions grows longer, there's been no official word on San Diego Comic-Con, which is still slated to take place in July for the time being. July appears to be the window most in the industry are (optimistically?) banking on things being up and running again, evidenced by Tenet and Mulan being slated for premieres that month. It's possible theaters may reopen by then, but fans shouldn't count on Comic-Con going on as usual.
No decisions have been made as of this writing, but the latest comments from California governor Gavin Newsom paint a bleak picture. He stated, "The prospect of mass gatherings is negligible at best until we get to herd immunity and we get to a vaccine. Large scale events that bring in hundreds, thousand, tens of thousands of strangers..is not in the cards."
That all but guarantees this year's Comic-Con is impossible (it feels like it's only a matter of time before that announcement is made), and it doesn't bode well for 2021's edition, either. Vaccines can take a long time to complete (12-18 months), so it's likely one for COVID-19 won't be available for a while. Since Newsom is waiting on a coronavirus vaccine before signing off on "mass gatherings," even next year's San Diego Comic-Con is in jeopardy. The event traditionally takes place in July, and 18 months from now (April 2020) is October 2021. That timeframe is actually in line with the prediction some health experts have that big events like sports games and concerts could be delayed until fall 2021, meaning cancelling next year's San Diego Comic-Con is a more realistic possibility than some people may want to admit. The city of San Diego and potential Comic-Con attendees would certainly love for the convention to happen as planned, but people's health has to come first. If it's not safe to hold Comic-Con, it's not worth the risk.
Due to the fluidity of the situation, it's impossible to say when stay-home orders and other restrictions will be lifted. Whenever it is time to reopen places, it will most assuredly be a slow, gradual process over time. Starting with institutions like restaurants and movie theaters (where it's easier to implement precautions to keep people separated) makes sense, and then everyone can see where things go from there. It would be extremely difficult to have that kind of control over San Diego Comic-Con, even if the convention center was capped at partial capacity. For example, Hall H can house 6,500 people, with the whole event routinely drawing well over 100,000 attendees annually. Until there is a reliable coronavirus vaccine in place, it's hard to see how San Diego Comic-Con and similar events can take place. And unless things rapidly improve, that may not be for another couple of years.