Experts warn U.S. may never reach herd immunity with COVID-19. Here s why
|CTVnews 04 May 2021 at 08:22|
Herd immunity with COVID-19 could come and go, scientists say. Or we might never reach it at all.
"There s a lot of things that have to go our way to actually get to herd immunity," said Dr. Christopher Murray, director of the University of Washington s Institute for Health Metrics and Evaluation.
And with vaccine hesitancy , "I m not sure that we are going to reach herd immunity," CNN Medical Analyst Dr. Leana Wen said.
But don t panic. Here s why it s possible to dip in and out of herd immunity, and what you can do now to maximize the chances of snuffing out COVID-19 for good:
"Herd immunity is the point where there s enough people that have been either infected or vaccinated that you basically can t sustain transmission in the community," Murray said.
"And if one case leads to less than one new infection, then eventually it peters out."
Estimates vary on how much of the population needs to have immunity to reach that goal.
Dr. Anthony Fauci, head of the U.S. National Institute of Allergy and Infectious Diseases, has said if 70-85% of people are immune. Board-certified internist Dr. Jorge Rodriguez estimates that number is about 85-90%.
"If we vaccinate 70% of the whole U.S. population, including kids, and then another 15-20% have already gotten (infected), I think we re pretty close to reaching a normalcy with the virus," he said.
But there s a big catch: No one younger than 16 can get a coronavirus vaccine in the United States right now. The Pfizer/BioNTech vaccine is authorized for those age 16 and older, and the Moderna and Johnson & Johnson vaccines are authorized for adults ages 18 and older.
All three vaccine makers are conducting vaccine trials with children. Some health experts say high school and middle school-age children could be vaccinated by this fall, but Fauci has said younger children will likely have to wait until early 2022 .
And that s a major obstacle for reaching herd immunity, as young people can still get infected and transmit the virus.
"We have already 25% of our population not eligible for the vaccine. I mean, we re already starting (with our) hands tied," said epidemiologist Ali Mokdad, a professor of health metrics sciences at the IHME.