Got questions about COVID-19 vaccines? We’ve got answers.

As new vaccines come on-line, more people are becoming eligible to be vaccinated against COVID-19.

Dr. Eneida Roldan, CEO of the FIU HealthCare Network and professor at the Herbert Wertheim College of Medicine, answers some frequently asked questions—from vaccine efficacy to cost.

Roldan is the medical director for the FIU COVID-19 vaccination site, the Miami-Dade testing site at the Fairgrounds, and the FIU campus test sites.

What's the difference between the three currently approved vaccines? Is one better than the other?
The Pfizer and Moderna vaccines use different technology to fight the virus than the Johnson & Johnson vaccine, but all three have received EUA (emergency use authorization) from the Food and Drug Administration.

Pfizer and Moderna vaccines require two doses—three weeks and four weeks apart, respectively. Pfizer is approved for ages 16 and older. Moderna is approved for 18 years and older. The Johnson & Johnson vaccine is a single shot. It is approved for 18 years and older.

Is one vaccine better than the other?
Because the vaccine clinical trials were conducted differently, it's a bit like comparing apples and oranges. All three vaccines have been deemed effective against SARS-CoV-2, the virus that causes COVID-19. The important message is to get vaccinated as soon as you become eligible.

Can you mix the vaccines?
No. In the case of Moderna and Pfizer vaccines, you should receive both shots of the same vaccine.

Can I get COVID-19 from the vaccine?
No. None of the vaccines contain SARS-CoV-2, so they can't give you COVID-19.

Can the vaccine make me sick?
You may have some side-effects after vaccination. The most common side effects include pain, redness and swelling on the arm where you receive the shot as well as chills, headache, body aches and fatigue. These symptoms usually go away after a couple of days. If they last longer, you may want to contact your health care provider.

Is it true that many people have a stronger reaction to the second dose?
Yes. And in most cases, that's a good thing. It means your immune system is doing what it is supposed to do. 

The first shot is a surprise to your immune system. When your body recognizes the "enemy" a second time, antibodies are ready to attack and may cause a stronger response. 

Older people who generally have a weaker immune system may have a lesser reaction.

How long does it take for the vaccine to start working, and how long does protection last? 
It usually takes a few weeks after the last dose for the body to build immunity. 

We don't know how long that protection will last, and the emergence of new coronavirus variants may complicate things. We may need annual shots as we do with flu vaccines.  

If I had COVID-19, do I still get vaccinated? 
Yes. Although contracting the virus should give you some protection against reinfection, again, we don't know how long that protection lasts. Even if you had COVID-19, we encourage you and everyone to get vaccinated as soon as the vaccine becomes available, and you are eligible.

Can I still get COVID-19 after getting the vaccine?
Yes. The vaccines are not totally foolproof, but if you get re-infected, you should experience milder symptoms.

Also, remember that it takes about two weeks after vaccination for the body to build immunity. So, it’s possible to contract COVID-19 before or just after vaccination since the vaccine did not have enough time to provide protection.

Do I still have to wear a mask after receiving the shots?
Yes. Vaccination is not a free ticket to let your guard down. To protect yourself and others, you should continue to wear a mask, follow social distancing and wash your hands often. The current research is not clear on whether a vaccinated person can still spread the virus.

Is the vaccine free?
Yes, the vaccine is free to everyone who lives in the United States, even if uninsured. If you have private insurance, Medicare or Medicaid, you may be asked for your insurance information. That's so your insurance can pay the provider who gave you the shot. The federal government will reimburse medical providers who administer COVID-19 vaccines to uninsured adults. 

Who should or shouldn't get a vaccine?
The CDC recommends vaccination for all adults except those who've had "a severe or immediate allergic reaction" to any of the ingredients in the vaccine. When in doubt, check with your doctor.

The Moderna and Johnson & Johnson vaccines are approved for people over 18 years old. The Pfizer vaccine is available for people over 16.

There are no COVID-19 vaccines currently approved for children, but clinical trials are underway, and we hope to have a vaccine for children before the end of the year.

Who can get vaccinated in Florida?
Because demand for COVID-19 vaccines is much higher than the supply, the State of Florida is prioritizing certain vulnerable groups. As more vaccines become available, eligibility is being expanded. For a list of who's eligible and a listing of vaccination sites, visit the Florida Health Department's Covid-19 Response website.