(CNN) – As the world awaits a COVID-19 vaccine, you may have heard the term “herd immunity.”
But what is it?
Herd immunity occurs when a virus is allowed to spread freely.
“It would mean that 60 to 70% of the population becomes infected,” according to Dr. Sanjay Gupta, CNN’s chief medical correspondent. “That’s a large enough number that they essentially create a herd of protection around other people.”
Experts say there’s a problem with that strategy.
Up to this point, some 220,000 people have died in the United States, but not even 10% of the people have been infected.
“If you start to multiply that times six or seven, that’s where you’re starting to get into the 1.4 to 2 million number that people who would potentially die,” Gupta said.
In addition, it’s uncertain how long immunity lasts once you get coronavirus.
Globally, the numbers would be many times higher.
The head of the World Health Organization worries a herd immunity approach could lead to more problems.
“Allowing a dangerous virus that we don’t fully understand to run free is simply unethical,” according to Tedros Adhanom Ghebreyesus, the World Health Organization’s director-general. “It’s not an option.”
Dr. Anthony Fauci agrees.
“There will be so many people in the community that you can’t shelter, that you can’t protect, who are going to get sick and get serious consequences,” the director of the National Institute of Allergy and Infectious Diseases said. “So, this idea that we have the power to protect the vulnerable is total nonsense.”