Central to the debate is how to minimize the risk from coronavirus variants that are more contagious than the original virus and threaten to make vaccines less effective.
Storyboard
The Second Dose Debate
Experts are split on whether to delay the second dose of COVID-19 vaccines to immunize more people. Prioritizing first doses means more vulnerable people get some protection, which could save lives. But doing so would increase the risk of more coronavirus mutations .
Consulting the Experts
The US needs to dish out as many first doses as it can to over-65s to "reduce the serious illnesses and deaths that are going to occur in the weeks ahead," Osterholm said.
"[The variants are] more transmissible, and if your immunity is only half what it should be, that will increase the risk of transmission," Schoub said.
While one shot gives "some" protection, data suggests two shots are "tenfold" better, Fauci said.
"What we have right now, and what we must go with, is the scientific data that we've accumulated," Dr. Fauci said.
Has anyone tried it?
Pfizer says that a single dose of its vaccine is about 52% effective, while getting a second dose makes it around 95% effective.
The Variants
All the variants contain mutations in the code for the part of the virus that it uses to infect cells. Alterations in this area could enable the virus to infect cells more easily.
