(CNN)The US Centers for Disease Control and Prevention told CNN Friday that the agency is tracking the Delta coronavirus variant, among others -- and warned that there is a small chance a fully vaccinated person could still get infected if they're exposed.
"Current data suggest that COVID-19 vaccines authorized for use in the United States offer protection against most variants currently spreading in the United States. However, some variants might cause illness in some people even after they are fully vaccinated," CDC spokesperson Jade Fulce told CNN in an email on Friday.
While Covid-19 vaccines are effective, Fulce said no vaccine is "100% effective at preventing illness."
And with millions of people getting vaccinated against the virus, some who are fully vaccinated "will still get sick if they are exposed," Fulce said.
"However, people with breakthrough infections may get less severely ill or have a shorter illness than they would have if they had not been vaccinated."
That's why experts are especially worried about people who have not yet gotten their Covid-19 shots.
More than 53% of the US population has received at least one Covid-19 vaccine dose and more than 45% is fully vaccinated, CDC data shows.
'Please get your second shot'
As officials urge more people to get their shots, the US surgeon general warns a big obstacle stands in their way: Misinformation.
"There is so much misinformation out there about the vaccine, coming through so many channels -- a lot of it being spread on social media," Dr. Vivek Murthy told CNN's Erin Burnett. "It's inducing a lot of fear among people."
"Two-thirds of those who are unvaccinated in polls say that they either believe the myths about Covid-19 or think that they might be true," he added.
Experts, including Dr. Anthony Fauci, have estimated that 70 to 85% of people in the US will need to become immune to the virus through vaccination or infection in order to control community spread. But after initial surges, vaccination rates have now slowed across the country.
And more than 1 in 10 people who have received one dose of the Pfizer/BioNTech or Moderna vaccine have missed their second dose, according to data shared with CNN by the CDC.
That statistic is especially concerning to experts because studies have shown that the vaccines are much more effective against the Delta variant after the two-dose series is completed.
"Please get your second shot," CDC Director Dr. Rochelle Walensky said in a Friday NPR interview. "What we do know is you get some protection from the first shot, but really that second shot gives you breadth and depth of vaccine coverage to really be able to tackle this Delta variant and other variants as well.
"If you missed your second within the time window, get it whenever, get it now, but do get that second shot," Walensky added.
Officials worried about unvaccinated Americans
The Delta variant is believed to be more transmissible and cause more severe disease than other strains. Murthy said he is worried for those who are unvaccinated as the variant spreads.
In Los Angeles County, the impact is already clear. Nearly all of the Covid-19 cases, hospitalizations, and deaths in Los Angeles County are occurring among people who are unvaccinated, county health officials said Thursday.
Out of nearly 437,000 positive coronavirus cases reported in L.A. County since December 2020, 99.6% of those were among individuals who were unvaccinated, health officials said in a press release.
"The virus is still with us," Los Angeles County Public Health Director Barbara Ferrer said at a press conference. "Even now, we need to be careful to mask and maintain distance from people outside of our households, especially if they're not yet vaccinated.''
Missouri hospitals stretched thin
Missouri is the state with the largest proportion of the Delta variant of Covid-19 infections, according to the CDC. And hospitals in the state are feeling the stress of managing Covid-19 patients on top of their regular intake, one hospital leader told CNN's Ana Cabrera on Thursday.
"Both hospitals here in town are stretched," said Erik Frederick, chief administrative officer at Mercy Hospital Springfield in Springfield, Missouri.
"We saw a very rapid escalation in our in-patient census starting June 1, we went from 26 to 90 in about three weeks. To go back to last year when our peak started, it took us six to seven weeks to escalate that quickly. Today to hit 97, it really took us almost two months to hit that level which we've done in under a month."
Frederick said a return of typical hospital patients is exacerbating the issue.
"The difference between last year and this we have traditional business back we didn't have last year during the initial surge. The demand for beds is higher for both Covid and non-Covid patients. It's definitely a stretch."
Frederick said there is also a high amount of pressure on available labor.
"The staff are right back into the mix of it, and I don't think they were fully recovered from last year," he said.
Smell and taste come back, studies show
In a bit of good news, researchers reported Thursday that those who did not regain their sense of taste and smell when they cleared their Covid-19 infections should get them back after a year.
Studies confirm that many, if not most, Covid-19 patients say their sense of smell is affected -- a condition called anosmia or hyposmia. Because smell and taste are closely linked, many people feel their ability to taste food normally is also affected when their sense of smell is disrupted.
An ongoing experiment of about 100 people who lost their sense of smell in early 2020 showed it can take months for it to come back, but it does. Some patients didn't realize or appreciate it, however, the international team of researchers reported in the Journal of the American Medical Association's JAMA Network Open.
"At eight months, objective olfactory assessment confirmed full recovery in 49 of 51 patients (96.1%)," they wrote. Two continued to have an abnormal sense of smell a year later -- one who couldn't smell much and another who had an abnormal smell sense.
"Our findings suggest that an additional 10% gain in recovery can be expected at 12 months, compared with studies with 6 months of follow-up that found only 85.9% of patients with recovery," they wrote.
