They didn’t claim it would be. They claimed it was 90% effective in the (time limited) study which they performed. It’s fair that you might have misinterprete

They didn’t claim it would be. They claimed it was 90% effective in the (time limited) study which they performed. It’s fair that you might have misinterpreted that as meaning it will be 90% effective. Especially if you don’t know how viruses work, but that’s not what was actually claimed.