The Most Common Coronavirus Vaccine Questions, Answered

Do the COVID-19 shots prevent infection? How long does immunity last? Do they work against mutations? Here's what to know.

Experts know and are learning a lot about the coronavirus vaccine, shots that offer many a glimmer of hope as the pandemic continues to rage on and as daily death counts reach all-time highs.

At this point, millions of Americans have received the coronavirus vaccine, which has given experts a clearer picture of the treatment and its impact on large groups of people. But there are still a lot of unknowns, too.

Here are answers to some of the most common vaccine questions right now:

Does the COVID-19 vaccine prevent you from spreading the virus to others who haven’t been vaccinated?

Answer: It is unknown right now.

William Moss, executive director of the International Vaccine Access Center at the Johns Hopkins Bloomberg School of Public Health, said we are still waiting on results from ongoing formal studies to determine whether vaccinated people can asymptomatically spread COVID-19 to those who are not vaccinated.

He noted that the end goal of the phase three vaccine trials, which served as the basis for the vaccines’ emergency use authorization by the Food and Drug Administration, was to look at clinical disease, not potential transmission from vaccinated individuals.

“The trials as they were originally designed were not able to address this question,” he said. “What we can say is that it’s highly likely that [the vaccine] reduces the risk of transmission, whether it prevents it completely, that is what we’ll have to see.”

It is known that there is a relationship between the amount of virus in a person and how severe the disease is, Moss said. “And we know that these vaccines can reduce the severity of disease and prevent disease, so it is highly likely that these vaccines also prevent the amount of virus within an individual and thus have an impact on transmission.”

He added that while it is likely that the coronavirus vaccines reduce the risk of transmission, we do not have data to prove that the vaccines completely prevent a vaccinated individual from asymptomatically transmitting the virus.

So, even after you’re vaccinated, it’s crucial to follow all public health measures (masking, social distancing and hand washing) to ensure you aren’t unknowingly spreading the virus to those around you.

How long does immunity last once you get the COVID-19 vaccine?

Answer: It’s not clear right now, but experts hope for *at least* a year.

Ongoing studies are currently examining the post-vaccine immunity timeline, but at this point, it is not known for certain how long immunity lasts after vaccination.

“From what I can tell, people who were vaccinated in the earliest parts of the trial are still showing signs of neutralizing immunity,” said Rachel Graham, an assistant professor in epidemiology at the Gillings School of Global Public Health at the University of North Carolina, Chapel Hill. She noted that at this point, that is just a few months.

Graham added that we’ll know more about the immunity timeline and how that affects the spread of COVID once further phases are rolled out.

“Hopefully we’ll get something that shows that immunity lasts at least a year so this vaccination can become part of your yearly vaccination program,” she said.

Should people who had COVID-19 still get vaccinated?

Answer: Yes.

While people who have had COVID-19 may think they’re protected, that may not actually be the case. There is a lot of variability in the immune response following natural infection, Moss said.

According to Sandra Albrecht, assistant professor in epidemiology at the Mailman School of Public Health at Columbia University in New York, people develop different levels of immunity after a natural COVID infection — some people have no antibodies, some people have low levels of antibodies and some people have high levels of antibodies. But there is no way to predict who is immune after natural infection, Albrecht added.

“We have really good information about how people respond to the vaccine, we have really good information on how protected they are. We just have a lot more confidence and certainty in the level of protection following vaccination,” Moss said.

That same kind of rigorous data does not exist for natural infection. “It is recommended that people who have had COVID-19 be vaccinated, it’s more about just being confident that they’re actually protected,” Moss added.

Should people who are worried about allergic reactions get the shot?

Answer: A majority of the time, yes. Talk with your doctor about your options.

Severe allergic reactions to the shots are extremely rare, Graham said. However, because the vaccine is so new, medical professionals will keep an eye on recipients after their shot in case of any issues.

“The vaccine administrator is going to ask you to hang around for 15 or 30 minutes after the vaccination is completed to make sure you don’t have any adverse reactions,” Graham said.

Graham added that when it comes to the coronavirus vaccine, the only recorded allergen that is potentially problematic for some is polyethylene glycol, which people would be exposed to in a high-test laxative like MiraLAX or in gut prep for a colonoscopy. “You would know if you’re allergic to it at this point,” Graham said.

Albrecht offered some solace by noting that the percentage of severe reactions is very small. So far there are only about 11 cases of severe reactions per 1 million administered doses. If someone does have a severe allergic reaction, there are immediate treatments that medical professionals can implement.

“Allergic reactions, in general, can be treated in that moment — that’s one of the reasons why individuals are encouraged to stay at the location after being vaccinated,” Albrecht said.

Before you get your COVID shot, it’s important to let your medical provider know if you have ever experienced anaphylaxis after a vaccine or medicine.

Will the vaccine protect against the new COVID-19 mutations?

Answer: Experts believe so. Right now, it’s known that the Pfizer vaccine is effective in protecting against new coronavirus variants; the Moderna vaccine is still being studied.

Over the past few weeks, new and more contagious coronavirus variants have popped up. The more contagious variants ― first identified in the UK and South Africa ― are now infecting people in additional countries too, including the United States. The Centers for Disease Control and Prevention believes the new variant will become the dominant strain in the U.S.

Albrecht noted that studies suggest the Pfizer vaccine is effective in protecting against both new variants discovered so far. She added that experts are waiting on data on the Moderna vaccine, which is still being processed, to see if it is effective as well. Moderna expects its vaccine to protect against the variants, too.

You do not have to pay for the vaccine in 2021.
Marko Geber via Getty Images
You do not have to pay for the vaccine in 2021.

Do you have to pay for the COVID-19 vaccine?

Answer: The vaccine is free in 2021.

The federal government is covering costs associated with the coronavirus vaccine through 2021, meaning the vaccine is free to receive through the end of this year, Graham said. Some healthcare providers may charge administration fees, though.

Even after the federal government ends financial coverage of the vaccine, the associated health care provider costs are expected to stay low, she noted.

“It’s a very novel strategy for making a vaccine. One of the main things is that the associated cost with producing the vaccine is extremely low,” she said, adding that this vaccine will likely be covered by insurance when we are out of the public health emergency.

“People should not worry about this becoming something that is going to be an expensive copay later on,” Graham added.

Is it safe for immunocompromised individuals or people who are pregnant to get the vaccine?

Answer: Both groups of people are encouraged to get the COVID-19 vaccine.

Earlier this winter, the American College of Obstetricians and Gynecologists stated that the COVID-19 vaccine should not be withheld from people who are pregnant, offering some reassurance to soon-to-be moms.

“So far, we haven’t seen any adverse events in this group,” Albrecht said. But, at the same time, there are probably not enough pregnant women who have been vaccinated to see anything come up in the data, she added.

Pregnant women were not included in the vaccine trials, which is normal; pregnant people are actually not included in most clinical research trials. And while there is not much data available currently, experts do not think the risks outweigh the coronavirus vaccine benefits.

For immunocompromised individuals, the CDC also recommends that they get the coronavirus vaccine when it is available to them. There is also not much data on adverse events and the efficacy rates in those who are immunocompromised, but people with stable HIV infections were included in the COVID-19 vaccine trials.

When deciding whether or not to get vaccinated, it’s important to remember that immunocompromised individuals and pregnant people are at higher risk for severe coronavirus disease. It’s also important to discuss any questions or concerns with your doctor.

What are the side effects?

Answer: Side effects include injection site pain, fever and headaches — but are anticipated and normal.

The side effects of the coronavirus vaccine vary from person to person. Many people experience no side effects at all, but most commonly, people reported injection site pain, headaches, low-grade fever, muscle aches and fatigue for a few days after injection. Overall, side effects are more common after the second dose of the two-dose vaccine.

The anticipated side effects are not a reason to worry; they are an expected immune response to the vaccine.

An immune response to a vaccine involves some degree of inflammation, which can come in the form of headache, injection site swelling or low-grade fever, according to Yvonne Maldonado, a pediatric infectious disease epidemiologist at Stanford University.

Side effects can be treated with anti-inflammatory drugs like Advil and Aleve, according to Moss.

Do most people trust the COVID-19 vaccine?

Answer: Yes, but there is a lot of misinformation still circulating around the shots.

“We’re trying to address a host of misinformation around the vaccine,” said Albrecht, who is also a part of Dear Pandemic, a social media-based organization made up of clinicians and researchers who are working to combat coronavirus misinformation by answering questions from the public and sharing easy-to-understand data.

“There are so many misconceptions, lots of misinformation and lots of conspiracy theories around it,” she added.

The misinformation around the vaccine is so rampant that Google has committed $3 million to efforts around fact-checking vaccine information in order to fight the misinformation that is already so prevalent and influencing so many people.

Albrecht added that a number of the circling conspiracy theories prey on people’s innate fears, drawing in folks who are already hesitant about vaccines in addition to those who may not have been nervous about vaccines in the past.

“We try to use the science and what we know about the vaccine,” Albrecht said. “That’s what we try to emphasize to help people sort through the misinformation out there.”

Is the vaccine rollout going well?

Answer: No, it’s pretty messy right now.

Moss stressed that a few aspects of the current mass vaccination process are less than ideal ― which was to be expected, to an extent. But the U.S. is currently faced with a ton of vaccine-related distribution issues, along with data-collection challenges and a lack of demand from those who are hesitant about the vaccine.

When it comes to mass vaccine campaigns, Moss noted that a lot of planning, resources and personnel are required. “I think we fell short on a lot of those areas,” he said. “We didn’t have the detailed planning that was required to do it successfully and effectively, and the states didn’t have the resources.”

He added that there was an assumption that a standard vaccine distribution plan through health care providers and pharmacies could work in this situation, but vaccine distribution to the scale that is necessary to inoculate large amounts of people requires much more.

Moss noted that there are calls for external vaccination sites in places like parking lots or schools, along with calls for a larger trained workforce to deliver the vaccines, which is promising.

“We want to see hospitalizations and death go down,” he said. “When we start seeing that, we’ll know we’re having an impact with these vaccines.”

Experts are still learning about COVID-19. The information in this story is what was known or available as of publication, but guidance can change as scientists discover more about the virus. Please check the Centers for Disease Control and Prevention for the most updated recommendations.