Alice Cooper says COVID-19 really "knocked" him out.

The 73-year-old rocker and his wife, Sheryl, 64, both previously had coronavirus and documented having their vaccinations in February.

And in a new interview, the 'Poison' hitmaker has opened up about how debilitating the virus can be and revealed he's now a "walking antibody".

Speaking to Good Day Rochester, Alice said: “All it really did with me was it knocked me out.

“For three weeks, I felt like I went 12 rounds with [boxing legend] Roberto Duran; I was just beat up.

“And then every day, you feel a little bit better, then you feel a little bit better, feel a little bit better, and after about a month, you start feeling pretty good. And so now I’m a walking antibody.”

The couple received their jabs at an immunisation centre in Phoenix, Arizona, set up by non-profit organisation, Team Rubicon, that utilises the skills of military veterans to "serve communities and to help people prepare, respond, and recover from disasters and humanitarian crises."

In a video shared on Team Rubicon’s Twitter page just after having a dose of the vaccine, Alice said at the time: “We already had COVID but we’re getting vaccinated anyway.

“Everyone out here has been really nice and you don’t feel like you’re in danger of anything. So come on out. If you haven’t been vaccinated, come on out.”

His dancer spouse, Sheryl, added that it was "painless".