Scientists Say Herd Immunity Might Be Achieved At 50% Or Lower: Report

Over a dozen scientists say the threshold to reach coronavirus herd immunity might be lower than they initially projected, The New York Times reported Monday.

According to scientists, herd immunity will be reached when the virus is unable to spread broadly because there are not enough vulnerable hosts, the Times reported. The consensus among scientists has been that 70% of a population needed to be immune through either vaccination or survival to reach herd immunity, according to the Times, but now several researchers claim threshold could be 50% or fewer.

“I’m quite prepared to believe that there are pockets in New York City and London which have substantial immunity,” said epidemiologist Bill Hanage of the Harvard T.H. Chan School of Public Health, the Times reported. “What happens this winter will reflect that.”

“The question of what it means for the population as a whole, however, is much more fraught,” Hanage said.

https://twitter.com/apoorva_nyc/status/1295356655140589568?ref_src=twsrc%5Etfw” target=”_blank” rel=”noopener noreferrer
Herd immunity is determined using an epidemic’s reproductive number — the number expresses how many people each infected individual spreads the virus to, the Times reported.

Initial calculations presumed every individual was equally susceptible to catching the virus and interacted randomly with every other person in the community, the Times reported.

“That doesn’t happen in real life,” said Dr. Saad Omer, director of the Yale Institute for Global Health, according to the Times. “Herd immunity could vary from group to group, and subpopulation to subpopulation.”

Estimates for herd immunity reportedly decreased when real-word variations of demographics and density were added to the equation, the Times reported. Some researched said herd immunity to coronavirus could be reached with as little 10 to 20 percent infected, the Times reported.