Achieving herd immunity to COVID-19 is a goal medical experts hope to meet with the eventual . CDC Director Robert Redfield testified before Congress Wednesday that even if a vaccine is approved and ready to start distributing in November, it would likely take until the for it to be "generally available to the American public so we can begin to take advantage of vaccine to get back to our regular life."
Butand the persistence of in U.S. society could be a barrier to defeating the virus.
"I am quite concerned, given the vaccine hesitancy of many Americans, that it's going to be challenging to get to that point," internal medicine specialist Dr. Shoshana Ungerleider told CBSN on Thursday. "So, all the more reason we need to be reliant on the science."
According to Johns Hopkins University, 70% to 90% of Americans would need to have coronavirus antibodies forto be achieved. Herd immunity helps protect vulnerable people like infants and those with compromised immune systems who can't get the vaccine.
However, vaccine opponents had already begun efforts to disparage the future vaccine, months before any clinical trials.
A mid-May poll conducted by the Associated Press and the University of Chicago found that only about half of Americans said they would get a COVID-19 vaccine, and nearly one-third weren't sure. About 1 in 5 people said they would refuse.
As the race towards a vaccine continues, social media platforms such as Twitter, Facebook and Instagram have flagged instances of COVID-19 misinformation, but have been accused of failing to do so when it comes to anti-vaccination posts.
Ungerleider encouraged those involved into "lead with data and encourage people that they are safe" to combat some Americans' "hesitancy."
"We need to continue on the course of the regulatory lines in order to get a really safe and effective vaccine approved here," she said.
Among the other challenges of COVID-19 vaccine distribution is the likelihood that two doses will be required several weeks apart.
"It's challenging for a number of reasons," Ungerleider explained. "The number of necessary doses doubles… you need to double everything in the supply chain."
She added that the logistics of having every American take two trips to receive the shots would further complicate distribution.
"Recognizing the significant challenges we face… if a vaccine candidate emerges this year — and that's still an if — it's really no wonder thatsaid it would really take until the second or third quarter of 2021 to start seeing results."