Image by WEF/Victor Tangermann

Bill Gates — the retired Microsoft co-founder turned philanthropist — has emerged as a surprisingly high-profile figure during the coronavirus pandemic, criticizing the government's response to the disease and raising money to distribute a vaccine.

Now, in a new interview with CNBC, Gates says that he's still optimistic that a vaccine is on the way. It's possible that one will be available by the end of the year, he said, but he considers it unlikely.

"The only vaccine that if everything went perfectly, might seek the emergency use license by the end of October, would be Pfizer," he said. "None of the vaccines are likely to seek approval in the U.S. before the end of October."

But by the very end of 2020 or 2021, the multibillionaire said, he thinks that the chances will start to get better and better.

"I do think once you get into, say, December or January, the chances are that at least two or three will (seek approval) — if the effectiveness is there," he told the network.

In the same interview, Gates also expressed optimism about the results of the vaccines under development by Moderna and AstraZeneca.

"We do see good antibody levels both in the phase one and the phase two, so we’re pretty hopeful," Gates said.

Both Russia and China have already approved emergency vaccines — but without testing rigorous enough to convince doctors.

“This is a reckless and foolish decision,” Francois Balloux, Professor of Computational Systems Biology at University College London said, told Science Media Centre in August.