With U.S. vaccination numbers far, the Food and Drug Administration is considering cutting doses of one vaccine in half to double its supply and speed up distribution.
So far, more than 4.5 million COVID shots have been given out, but that's just a fraction of the 20 million initially expected by the end of 2020.
Long lines in Florida, Tennessee and Texas are where overburdened systems meet overwhelming demand.
"I have high blood pressure. I have diabetes, I have susceptibility to pneumonia. I'll wait a whole day for this if I have to, you know," Alex Wathen told CBS News.
Florida's governor pinned the problem on some hospitals.
"Hospitals that don't do a good job of getting the vaccine out will have their allotment transferred to hospitals that are doing a good job of getting the vaccine out," Governor Ron DeSantis said.
But the governor's decision to open up vaccination to anyone over 65 — ahead of some essential workers — has added to the crunch.
Dr. Robert Goldszer said Mt. Sinai Medical Center in Miami Beach has 10,000 people scheduled. "We're going full tilt, we're going to 7 p.m. at night, Saturday and Sunday," Goldszer said.
There is debate on whether to give half doses of the Moderna vaccine to people between 18 and 55 years old, doubling the number of people who can take it.
"We know it induces identical immune response to the hundred microgram dose and therefore we are in discussion with Moderna and with the FDA," Dr. Moncef Slaoui, the head of Operation Warp Speed, told "" on Sunday.
In Britain on Monday, another first: Oxford and AstraZeneca'sstarted to roll out. It likely will be months before that can happen in the U.S.
Meanwhile, vaccine sabotage is adding to the problems. On Monday, Steven Brandenburg appeared before a judge in Wisconsin, accused ofhundreds of doses at a hospital outside Milwaukee where he worked as a pharmacist. Prosecutors said Brandenburg believed the vaccine was unsafe.
There is progress: In Queens, New York, nurse Sandra Lindsay, who famously received one of the first doses of Pfizer's vaccine, got her second dose to complete the vaccination.
"But the burden feels definitely much lighter today," Lindsay said. "And I am very, very grateful."