Danny Altmann, a professor of immunology at Imperial College London, told CNBC that only 10 to 15 percent of the population of a town or city is likely to be immune to COVID-19.
“And immunity to this thing looks rather fragile — it looks like some people might have antibodies for a few months and then it might wane, so it’s not looking like a safe bet,” he told the network. “It’s a very deceitful virus and immunity to it is very confusing and rather short-lived.”
He also warned that a second wave of infections is possible, but governments are better prepared to handle the outbreak than when the virus first took a grip on the world months ago.
“Anybody who thinks that it has got more mild or gone away or that somehow the problem’s going to solve itself is kidding themselves,” he told CNBC. “It’s still a very lethal virus, it still infects people very, very readily. And I think humanity isn’t used to dealing with those realities."
“The devil is in the detail, vaccines aren’t that easy,” Altmann added. “There’s more than 100 in trial at the moment, and many things can go wrong along the way. I place no bets at the moment myself.”
The World Health Organization warned last week that the virus is spreading as many countries begin lifting lockdown measures to repair their shattered economies.
“Although many countries have made some progress, globally, the pandemic is actually speeding up,” said WHO Director-General Tedros Adhanom Ghebreyesus during a June 29 briefing.
As of Monday, more than 11.5 million people have tested positive and over 535,400 have died, according to Johns Hopkins University.
Altmann told CNBC lawmakers need to find a balance between protecting individuals and preventing an economic freefall. However, he cautioned the main goal is to prevent more infections.
“We need to continue to be led by the science and the medicine and do the right thing," he said. "And doing the right thing means everything you can do to block transmission.”