On Monday, health-care workers in Pittsburgh, New York, and other cities became the first Americans to get the COVID-19 vaccine, and more than 100,000 doses of the vaccine are headed to hospitals in Pennsylvania.

We spoke with two employment lawyers — Ballard Spahr’s Shannon Farmer, who represents employers, and Community Legal Services’ Rhiannon DiClemente, who represents workers — to figure out what you need to know about vaccine requirements on the job.

A reminder: The vaccine is not yet widely available, so most employers cannot require it right now, even if they wanted and were legally able to. And since we’re in the uncharted territory of COVID-19, it’s possible that vaccine guidelines will change as time goes on.

In the following guide, we’re talking specifically about private employers and their employees — not independent contractors or gig workers.

Can my employer require me to get the vaccine?

It’s possible, but that depends on several factors, including who your employer is and what your personal situation is. Still, it’s likely that more employers will encourage the vaccine rather than require it.

There’s another factor, too: Right now, the vaccine is being distributed under emergency authorization from the Food and Drug Administration, which requires less evidence of safety and effectiveness than full approval. (Though data show the immunization far exceeded hopes in clinical trials.) Before any federal guidance was released, experts had questioned whether the emergency authorization would affect an employer’s ability to mandate a vaccine.

On Wednesday, Dec. 16, the U.S. Equal Employment Opportunity Commission updated its guidance on vaccines, saying that emergency authorization does not change an employer’s legal ability to require a vaccine, Farmer said.

Setting aside emergency authorization, other factors can affect whether your employer could require the vaccine. Your employer would need to be able to show that it’s necessary for the job — that could mean you work in a high-risk environment, such as a hospital or a long-term care facility, and that the vaccine is necessary to keep patients and employees safe — or that there’s a “direct threat,” DiClemente said. The EEOC and CDC have deemed COVID-19 a “direct threat.” That means that if you work in a high-risk environment, employers could likely make the case for requiring a vaccine. But if you work from home, they probably can’t.

Government employers may have “additional hoops to jump through” to be able to require the vaccine, Farmer said. And, she said, some states have restrictions on requiring vaccines, but Pennsylvania doesn’t.

What if I don’t want or can’t get the vaccine?

If your employer is able to make the legal case for requiring the vaccine and you don’t want or can’t get the vaccine, your employer might have to accommodate you, depending on your reasoning.

If you can’t get the vaccine for religious or medical reasons, your employer is legally obligated to accommodate you. But if you don’t want the shot for a political belief — say, you’re opposed to vaccines — your employer likely does not have to accommodate you.

Can I get fired for not getting the vaccine if my employer requires it?

Probably. Pennsylvania, like most of the country, is an “at-will” state. That means your employer can fire you for any reason at any time, except for certain identity reasons (you can’t be fired for being a woman, for example). Union members, however, are usually protected by “just cause” clauses, which say that workers can only be fired for cause.

Will employers require workers to get the vaccine?

That’s still unclear. Temple University Health System said earlier this month that it had no current plans to require vaccination. Penn Medicine and Jefferson also said the vaccine would be voluntary.

Farmer said it’s likely more employers will opt to encourage the vaccine.

Employers who require it will have to be prepared for a number of issues, including working with employees on a case-by-case basis depending on if they need an accommodation and being willing to fire people if they don’t get it. An employer’s willingness to fire workers over the vaccine will depend in part on how easy it is for them to hire workers in their industry, Farmer said.

In the coming months, as the vaccine becomes more widely available, certain types of employers, like music venues or indoor sporting arenas, may consider requiring employees and patrons to prove they got the vaccine in order to open up, Farmer said.

» READ MORE: I’m back at work and I don’t feel safe. What can I do?

What if something happened to me after I got the vaccine because it was required on the job?

If you have a side effect, like a fever, and have to take off work, it depends on what your employer’s policy is. Some health-care employers have said that workers will need to use their personal time, which workers are concerned about, said the American Federation of Teachers union, which represents nurses and other health-care workers.

In terms of employer liability, Farmer said that in similar cases that have been litigated, these situations have often been treated as a workplace-related injury.

What if the vaccine is required at my job but it’s hard to get it?

This will be an area to watch, DiClemente said. Right now, we don’t know enough about how vaccine rollout will work. Will people have to pay for it? Will it take a long time to get access to it? If your job requires you get vaccinated but it’s hard to get it, there will likely not be any law that protects your job if your employer is trying to fire you for not getting the vaccine, DiClemente said.

You could, however, work with your coworkers to make demands on your employer about vaccine policy, whether or not your employer requires it, DiClemente said. Do you think your employer should pay for employees to get vaccinated? Should employees get paid leave while they wait for the vaccine and are able to return to work? You can get together with your coworkers to discuss these issues and demand them from your boss. You’ll be protected under the National Labor Relations Act, which says that workers cannot be fired or retaliated against for trying to improve their working conditions.