COVID-19 will hardly be eliminated by a vaccine, and will likely circulate and be endemic, Sir Patrick Vallance, Chief Scientific Adviser to the UK government, told Members of Parliament (MPs) on Monday.
Only from the phase three clinical trials, we can find out if the vaccines "actually stop you from getting infected" and how effective they are, Vallance said.
"And at that point, we'll also have some clear idea on the safety profile of these vaccines, and from there can start looking at what a sensible vaccination strategy could be across the population," he added.
Vallance said he had been "clear right from January" that he didn't think a vaccine would be widely available before spring next year.
"The notion of eliminating COVID from anywhere ...is not right, because it'll come back," Vallance told the MPs.
Vallance said it is worth reflecting that only one human disease—smallpox—has been "truly eradicated" by vaccine.
"It's a very difficult thing to do," he said.
"I think it's unlikely that we will end up with a truly sterilising vaccine by something that completely stops infection. And it's likely that this disease will circulate, and be endemic," he said, "that's the view of many people on SAGE [Scientific Advisory Group for Emergencies] that's the likely outcome."
Vallance said a vaccine will likely "decrease the chance of infection and the severity of disease," and the pandemic will start "to look more like annual flu than anything else."
Vallance said infectious disease pandemics remain "the highest risk by far" that the UK will face in the coming decades.