People are likely to need a booster dose of vaccine six to 12 months after their first round, Albert Bourla, CEO of Pfizer, said.

Real-world data shows the Pfizer vaccine is effective against a worrying variant of coronavirus first seen in South Africa, called B.1.351, Bourla said during a CVS Health Live event posted to Facebook Thursday. “Protection goes down by time but still in six months it’s still extremely, extremely high,” he said.

“If you ask me, I think that there will be a need, based on these data, for revaccinations,” Bourla added.

Bourla said it remains to be seen how often this would have to happen, but “a likely scenario is that there will be likely a need for a third dose somewhere between six and 12 months and then from there, there will be an annual re-vaccination. But all this needs to be confirmed.”

“In pandemics, you are as protected as your neighbor,” Bourla said. He said that’s why it’s important that all countries get their citizens vaccinated.