Experts have made it clear: to overcome the Covid-19 pandemic, America needs to get vaccinated.
And that includes younger Americans, some of whom still are hesitant or may think they don't have as much to fear from the virus.
Everyone 16 and older is currently eligible for a Covid-19 vaccine. But a recent Quinnipiac University poll found 36% of adults under the age of 35 don't plan on getting one.
Here's why it matters that young groups sign up for the shots: When Centers for Disease Control and Prevention Director Dr. Rochelle Walensky warned of a rise in Covid-19 cases and hospitalizations earlier this month, that increase was predominantly among younger adults, most of whom were not vaccinated.
Despite the push for more vaccinations, state and local leaders are seeing a decrease in demand. As a result, they're asking vaccine manufacturers to scale down the size of vials and how much is distributed.
"Many of our health departments, especially those in rural America, are providing feedback that they either need smaller dosage vials or we may have to contend with waste," said Lori Tremmel Freeman, CEO of the National Association of County and City Health Officials.
Pfizer said Thursday it will begin offering smaller shipment sizes of its Covid-19 vaccine at the end of May to give vaccine sites more flexibility.
The current shipment size is a 195-vial pack that contains 1,170 doses. The smaller shipment sizes will come in three 25-vial packs which contain a total of 450 doses. Vaccination sites will have the option to order either size.
Some experts estimate that to suppress the spread of the virus, somewhere between 70% to 85% of the US population needs to be immune. So far, roughly 43% of the country has received at least one Covid-19 vaccine dose and about 29.5% is fully vaccinated, according to CDC data.
About 35% of the US population has been infected with the virus that causes Covid-19, the CDC said Thursday. The agency estimates the virus has led to 114.6 million infections, 97.1 million symptomatic illnesses and 5.6 million hospitalizations from February 2020 to March 2021.
The more people are vaccinated, the fewer opportunities the virus has to not only transmit but to further mutate. And we already know what those mutations could mean. One coronavirus variant, for example, which became the dominant strain in the US, helped fuel recent Covid-19 spikes in several states, including Michigan. That strain, the B.1.1.7 variant, is more contagious and hit younger people particularly hard.
And there's another major reason young people shouldn't turn away from the shot: long-term consequences of Covid-19.
"One critical way to prevent long Covid is to prevent Covid itself," National Institutes of Health Director Dr. Francis Collins said at a House Energy and Commerce subcommittee hearing on Wednesday.
"Even for young people who consider their risk of severe Covid to be low, the long-term consequences can be quite serious," he added. "So long Covid represents one more reason to encourage everyone age 16 and over to get vaccinated as quickly as possible."
And those long-lasting symptoms can develop even in people who have mild cases of Covid-19. Americans have reported dozens of persistent symptoms that last months after their infection, including fatigue, headaches, memory loss, gastrointestinal problems, muscle aches, heart palpitations and loss of smell or taste.