Dr David Nabarro, the World Health Organisation special envoy on COVID-19, said the new coronavirus is "by and large much more stable than many other viruses that we deal with".
Speaking to the All-Party Parliamentary Group on Coronavirus, he said: "So we're basically saying, my colleagues and I, just recognise that we as humanity are going to have to live with this virus for the foreseeable future.
"Living with the virus means holding it at bay, it doesn't mean letting it come and infect anybody and not worrying about it.
"The talk about herd immunity as a strategy is not viable, it's not ethical, it's not based on anything that we've ever done before.
"We encourage everybody to just put that one on the side, we may change our advice, but right now that's not the advice."