Your workplace might not have a vaccine mandate, but that could change soon — or not, depending on some legal drama.

On Saturday, a federal appeals court temporarily blocked a vaccine mandate issued by the Biden administration last week. The mandate stated that by January 4, all U.S. businesses with 100 or more employees will need to either institute a mandatory Covid vaccine policy or require that all unvaccinated employees wear a mask at work while getting tested for Covid regularly.

The Labor Department's top lawyer, Seema Nanda, said that the Biden administration is "fully prepared to defend this standard in court," in a statement Friday.

For some workplaces, such a mandate might not be a problem: As of Monday morning, roughly 70% of Americans ages 18 and older are fully vaccinated against Covid, according to data from the Centers for Disease Control and Prevention.

But among the country's unvaccinated population, many people remain deeply hesitant. Last month, a Kaiser Family Foundation survey found that 16% of Americans plan to never get vaccinated against Covid, and 4% only plan to get vaccinated if they're required to for work, school or other activities.

The Biden administration's mandate, which would apply to more than 84 million workers across approximately two-thirds of the private workforce, could test those numbers.

Many of those unvaccinated people have a wide array of reasons, often borne from misinformation, for avoiding the shot. A new Kaiser Family Foundation report published Monday found that 78% of surveyed adults either believe at least one piece of misinformation about the Covid disease or vaccines, or they're unsure whether that misinformation is true or false.

Here are six common myths and misconceptions about the Covid vaccines, and what experts say is true instead:

Myth: People who had Covid don't need to get vaccinated

If you've gotten Covid and recovered from it, you probably do have a degree of natural immunity against the virus now. But a new CDC study published last week found that unvaccinated people who'd recovered from Covid were five times as likely to catch it again, compared to people who got two doses of an mRNA vaccine from Pfizer or Moderna.

Vaccine-induced immunity against Covid is more protective, robust and consistent than natural immunity, according to the study. In other words, a vaccine will protect you significantly more against getting Covid again, a particular concern as new mutations develop.

The CDC currently recommends that anyone who's at least 5 years old should get vaccinated, even people who've already recovered from a bout with Covid. "We now have additional evidence that reaffirms the importance of Covid-19 vaccines, even if you have had prior infection," CDC Director Dr. Rochelle Walensky said in a statement Friday.

Myth: You shouldn't get vaccinated if you're trying to have a baby

According to the CDC, it's totally safe to get vaccinated against Covid if you're pregnant — and there's no evidence that the authorized Covid vaccines can cause fertility issues in men or women.

That's significant: Pregnant people have a high risk of severe illness from Covid, Keri Althoff, an epidemiologist at the Johns Hopkins Bloomberg School of Public Health, tells CNBC Make It.

And if you get Covid while pregnant, you also have a much higher risk of preterm delivery, neonatal intensive care, ICU admissions and death compared to women of the same age who aren't pregnant, says Dr. Lisa Hansard, a reproductive endocrinology and infertility specialist with Texas Fertility Center.

Yet in Monday's Kaiser Family Foundation survey, 17% of respondents said they'd heard that pregnant women shouldn't get the vaccine, while 8% believed that the vaccines cause infertility. As of Oct. 30, only 35% of people in the U.S. who have gotten pregnant since the vaccines were authorized are fully vaccinated, according to CDC data.

Those who've gotten pregnant have fared well. A recent CDC study on 1,613 pregnant women who got the Covid vaccine in their second or third trimesters found no increase in miscarriages or birth defects. And their children seem to bear no ill effects from their parents' vaccines, Dr. Lee Savio Beers, president of the American Academy of Pediatrics, told CNBC Make It last month.

Studies even suggest that pregnant people who are vaccinated against Covid can pass along protective immunity to their newborn through breastmilk and placenta — which is particularly important, since children under age 5 aren't eligible to get vaccinated yet.

Myth: Experts rushed to develop mRNA vaccines, so they can't be safe

Researchers developed the mRNA vaccines for Covid at a historic pace — but the technology isn't brand new. In fact, it's been under development for decades: Scientists started testing the first mRNA vaccines in mice in the 1990s.

Historically, mRNA vaccines have been too expensive and difficult to manufacture at scale, Dr. Margaret Liu, a physician and board chair of the International Society for Vaccines, told NPR in May. But when the pandemic hit last year, the technology was essentially in the right place at the right time for widescale deployment.

It's more than just lucky timing, too. The country's approved Covid vaccines have been subject to the most intense scrutiny and testing processes in American history.

"We're 425 million doses deep in the United States, and the systems are watching," Althoff says. "So, if you've ever wanted to know a ton about a vaccine, this this is the moment. This is the vaccine."

Even now, as more than 177 million people have received mRNA vaccines from Pfizer and Moderna, the CDC and the U.S. Food and Drug Administration still constantly monitor safety data.

Myth: mRNA vaccines can alter your DNA

Neither of the country's approved mRNA vaccines messes with your DNA.

In Monday's Kaiser Family Foundation survey, 8% of people surveyed believed this particular myth. The confusion is understandable: DNA and RNA are often mentioned side-by-side in biology classes. DNA stores and transfers your body's genetic information, while RNA helps your body create amino acids and proteins.

Pfizer and Moderna's vaccines work by sending messenger RNA, or mRNA, into your body's cells. The mRNA instructs those cells to make a harmless form of the "spike protein" found on the virus that causes Covid. Your immune system then recognizes that protein as foreign, and creates brand-new antibodies — ones that it's never needed before — to fight the protein off.

In essence, the vaccines help your body create a blueprint for fighting against Covid, so that if you're exposed to the virus, your immune system can immediately ward it off before it takes root.

No DNA involved.

Myth: Covid vaccines could have long-term side effects that have yet to reveal themselves

It's been 20 months since the first people got vaccinated in U.S. clinical trials, and 11 months since the country's vaccine rollout started. Researchers have yet to detect any long-term health problems associated with the vaccines.

All three of the country's authorized Covid vaccines can come with uncomfortable side effects in the 24 to 48 hours following the shot, like pain, a headache or a fever. That's often a sign that the vaccine is working as intended: You feel sick because your body thinks it's fighting off a dangerous virus, even though it isn't.

The symptoms typically disappear when your immune system finishes building its protection against Covid, usually within a few days.

For those who want to keep waiting for potential long-term side effects to emerge, Althoff says decades of data from mRNA vaccine clinical trials show that you don't need to be concerned. And, she adds: "We will continue to watch for all those who are skeptical."

Myth: The vaccine causes the Covid virus to mutate into more dangerous variants

In May, the three vaccines became widely available to all U.S. adults. Two months later, the delta variant became the country's dominant strain of Covid — causing some people to link the two events.

Althoff says the theory simply doesn't make sense, based on both pure logic and the known science of how viruses evolve.

The longer a virus can spread within a population, the more time it has to evolve and find new ways to counteract the body's defenses. By July, the virus that causes Covid had already been circulating in the U.S. for well over a year — plenty of time for a dangerous mutation like delta to emerge.

And since vaccinations help limit the spread of viruses, they actually reduce the likelihood of new variants emerging.

"The more replicating virus, the higher number of mutations and the greater likelihood of variants," Althoff says. "So, in order to stop a viral replication, you build immunity in the population — and that's what the vaccine does."

Update: This story has been updated to reflect a federal appeals panel's temporary block on the Biden administration's vaccine mandate, and new Kaiser Family Foundation survey findings on the spread of Covid misinformation.

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