Bill Gates, co-founder of Microsoft MSFT, +1.30%, offered up some “bad news” in a CNN interview on Sunday for those feeling optimistic over the imminent U.S. arrival of the first COVID-19 vaccine.

 ”Sadly, the next four to six months could be the worst of the pandemic. The IHME forecast shows over 200,000 additional deaths. If we would follow the rules, in terms of wearing masks and not mixing, we could avoid a large percentage of those deaths.“

In other words, keep expectations for the vaccine’s impact in check.

“I thought the U.S. would do a better job handling it,” Gates explained to CNN host Jake Tapper. “This virus could be more fatal than it is. We didn’t get the worst-case. But the thing that has surprised me is that the economic impact in the U.S. and around the world has been much greater than the forecasts that I made five years ago.”

Gates also said that we can expect the world to start its long-awaited return to normalcy as early as the summer of 2021, with a few caveats.

“Even through early 2022, unless we help other countries get rid of this disease and we get high vaccinations rates in our country, the risk of reintroduction will be there,” he said. “And, of course, the global economy will be slowed down, which hurts America’s economy in a pretty dramatic way. “/CNN