Coronavirus vaccine FAQs: What you need to know

The race is on to get Americans vaccinated against COVID-19.

People in the D.C. area are eager to get shots, and every week, it seems, more venues are offering vaccine doses — but supply remains extremely limited, which has led to some frustration and confusion over where, how and when to get vaccinated.

Here’s what you need to know.

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Looking for more information? D.C., Maryland and Virginia are each releasing more data every day. Visit their official sites here: Virginia | Maryland | D.C.

  • Q: Can I get a vaccine in the D.C. area?
  • Across the D.C. area, officials are rolling out the coronavirus vaccines in phases. In general, vaccines are still limited to those in the health care field and some other front-line workers, as well as the area’s oldest residents. However, there are differences across each jurisdiction.


    Virginia is currently in its version of Phase 1b of the vaccine rollout. This includes front line essential workers, such as police and firefighters, teachers and grocery store workers; people 65 and older, people 16-64 with high-risk medical conditions.

    You can see more details about eligibility in Virginia on the state’s department of health website.

    Virginia health officials announced the launch of a new statewide pre-registration system starting Feb. 16. (Fairfax County, however will not be participating in the statewide system.)

    However, county health department clinics may have specific steps for registering for appointments and, given the low supply, may be prioritizing certain populations only:

    In addition to health department clinics, some CVS pharmacies in Virginia are also offering the vaccine.


    In Maryland, the vaccination rollout statewide is now in Phase 2a, which includes residents 60 and older, as well as teachers and other front-line essential workers.

    You can see the full list of people in Maryland’s Phase 2a on the state’s coronavirus website. However, remember, your local health department may only be prioritizing certain groups.

    Maryland has a COVID-19 vaccine locator and map you can use to find a site near you. These sites include clinics run by local health departments, as well as sites run by hospital and retail pharmacies, such as Giant and Safeway. Be warned, however, that most sites are being hit with heavy demand and you might not be able to find an open appointment right away.

    The state is also planning 12 mass vaccination sites across Maryland. Six sites are already open. You can pre-register online for an appointment at one of the sites. In the D.C. area, there is mass-vaccine site already up and running at Six Flags in Prince George’s County. Another mass vaccination site is set for the Germantown campus of Montgomery College in Montgomery County.

    To get vaccinated at a clinic run by your local health department, you must pre-register. See links below to Maryland health departments in the D.C. area.

    It’s also important when you receive a link to make an appointment, that you don’t share that with others or post it online in a Facebook group or Listserv. Officials say that results in ineligible people making appointments and gums up the works.


    In D.C., if you’re over 65 you can sign up for a shot by calling 855-363-0333 or using D.C.’s online portal. Here’s where you can make an appointment in D.C.

  • Q: How is the rollout going in general?
  • Around the country and in the D.C. area, the initial rollout has been shaky. The No. 1 problem around the country is limited supply, even as demand for the shots has surged. Locally, the rollout has led to frustration and confusion about how to sign up for shots, eligibility rules and tech problems, as well as concerns about equal access to the shots.

    Despite the confusion, shots are getting into arms, slowly but surely. Track vaccinations across D.C., Maryland and Virginia on WTOP’s vaccination tracker.

    Local officials are hopeful more supply is coming.

    President Joe Biden has set a goal of 100 million shots in his first 100 days in office — a goal that experts say the U.S. is on track to exceed.

    In addition, the Biden administration has secured more doses — a total of 600 million doses through the end of July. That’s enough doses to inoculate 300 million Americans, since the vaccines purchased required two shots.

  • Q: How many different kinds of COVID-19 vaccines are there?
  • The pace of vaccinations could increase even more if a third vaccine from Johnson & Johnson receives authorization from the Food and Drug Administration.

    There are currently two COVID-19 vaccines in circulation. One is made by Pfizer-BioNTech and the other is made by Moderna. Both require two shots.

    For Pfizer, the booster shot is needed three weeks after your first shot. For Moderna’s, it’s four weeks.

    The Pfizer requires deep-freeze storage.

    The Johnson & Johnson vaccine is unique because it only requires one shot. The FDA has scheduled a meeting Feb. 26, when advisers will review the data and decide whether to green-light the vaccine option.

    Another vaccine option, made by the pharmaceutical company AstraZeneca has been authorized in other parts of the world but not in the U.S.

  • Q: When will vaccines be widely available?
  • Dr. Anthony Fauci, the nation’s top infectious diseases doctor said he expects the pace of vaccinations to pick up over the next few months and predicted it would be “open season” around April, meaning anyone — not just those in high-risk groups — could sign up for the shots.

  • Q: How effective have the vaccines been in trials?
  • Pfizer and Moderna are reporting preliminary results from late-stage trials that show their vaccines are almost 95% effective.

    AstraZeneca says its vaccine is up to 90% effective.

  • Q: What does 'vaccine efficacy' or efficiency mean?
  • Percentages in vaccine efficacy and vaccine effectiveness describes “the proportionate reduction in disease among the vaccinated group. So a VE of 90% indicates a 90% reduction in disease occurrence among the vaccinated group, or a 90% reduction from the number of cases you would expect if they have not been vaccinated,” according to the CDC.

    There’s a formula for it:

    “Vaccine efficacy/effectiveness (VE) is measured by calculating the risk of disease among vaccinated and unvaccinated persons and determining the percentage reduction in risk of disease among vaccinated persons relative to unvaccinated persons. The greater the percentage reduction of illness in the vaccinated group, the greater the vaccine efficacy/effectiveness.

    The basic formula is written as:

    Risk among unvaccinated group − risk among vaccinated group
    Risk among unvaccinated group OR: 1 − risk ratio

    In the first formula, the numerator (risk among unvaccinated − risk among vaccinated) is sometimes called the risk difference or excess risk.”

  • Q: What are the differences between the vaccines?
  • The vaccines differ in doses and distribution requirements.

    A half-dose of AstraZeneca‘s vaccine followed by a full dose at least one month later was 90% effective.

    Both Pfizer and Moderna‘s vaccines require two shots. For Pfizer, the booster shot is needed three weeks after your first shot. For Moderna’s, it’s four weeks.

    AstraZeneca’s vaccine doesn’t need to be stored at ultracold temperatures, making it easier to distribute, especially in developing countries. It can be transported under “normal refrigerated conditions” of 2 to 8 degrees Celsius (36 to 46 degrees Fahrenheit).

    Pfizer, on the other hand, plans to distribute its vaccine using specially designed “thermal shippers” that use dry ice to maintain temperatures of minus-70 degrees Celsius (minus-94 degrees Fahrenheit).

  • Q: How do the vaccines work?
  • AstraZeneca’s vaccine uses a weakened version of a common cold virus that is combined with genetic material for the characteristic spike protein of the virus that causes COVID-19. After vaccination, the spike protein primes the immune system to attack the virus if it later infects the body. Pfizer and Moderna’s vaccines also teach the immune system to recognize coronavirus, through messenger RNA.

    The CDC has an explainer on how vaccines work online.

  • Q: Does the vaccine mean the pandemic is over?
  • Nope.

    Dr. Anthony Fauci, the top disease expert in the U.S., told CBS that for there to be herd immunity requires that a majority of the country be vaccinated.

    “If you have a highly efficacious vaccine, and only a relatively small 40, 50% of the people get vaccinated, you’re not going to get the herd immunity you need,” Fauci said. “What we do need is we need to get as many people as possible vaccinated.”

    The CDC cautions that experts “do not know what percentage of people would need to get vaccinated to achieve herd immunity.”

    What exactly is herd immunity?

    Per the CDC: “Herd immunity is a term used to describe when enough people have protection — either from previous infection or vaccination — that it is unlikely a virus or bacteria can spread and cause disease. As a result, everyone within the community is protected even if some people don’t have any protection themselves. The percentage of people who need to have protection in order to achieve herd immunity varies by disease.”

  • Q: What can Americans do until we've all been vaccinated?
  • Stay safe: Wear a mask, wash your hands, use hand sanitizer, reduce your risk of exposure, check for symptoms and get tested.

    The Associated Press contributed to this report.

The Associated Press contributed to this report.

Jack Moore

Jack Moore joined as a digital writer/editor in July 2016. Previous to his current role, he covered federal government management and technology as the news editor at, part of Government Executive Media Group.

Will Vitka

William Vitka is a Digital Writer/Editor for He's been in the news industry for over a decade. Before joining WTOP, he worked for CBS News, Stuff Magazine, The New York Post and wrote a variety of books—about a dozen of them, with more to come.

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