When Will a COVID-19 Vaccine Be Available — and Who Will Get It First?

The finish line in the race to make a safe and effective COVID-19 vaccine available to the masses is finally within sight. In the last month, biopharmaceutical company Pfizer shared that its vaccine was "more than 90 percent effective" in protecting the body from COVID-19 infection in a large-scale study of more than 43,000 people, and biotechnology company Moderna announced its vaccine was 94.5 percent effectivein protecting more than 30,000 study participants from COVID-19 infection. Both companies say their results have uncovered no serious safety concerns, though they're continuing to collect safety and efficacy data to be totally sure of their findings. As of now, it's unknown whether a vaccine could prevent COVID-19 transmission (meaning it's unclear whether an asymptomatic person might still be able to spread the virus even after they're vaccinated).

In the meantime, the two companies have applied to the Food and Drug Administration (FDA) for emergency use authorization (EUA) of their respective vaccines, meaning they could start to roll out to the public before the new year if authorized — as in, less than a month.

If that sounds fast, that's because it is. It can typically take as long as a decade (maybe more) to develop a vaccine for a new virus, says Erika Schwartz, M.D., an internist who specializes in disease prevention. (

But thanks to existing research on the general family of coronaviruses (following the SARS and MERS outbreaks, two other coronaviruses that previously spread around the world) and the speedier process of carrying out studies remotely, promising COVID-19 vaccines have emerged in a matter of months. Considering there are several other vaccine efforts currently underway in addition to Pfizer's and Moderna's, these two companies won't be the only ones inching closer to requesting FDA authorization.

Of course, that doesn't mean a COVID-19 vaccine will become a reality overnight — at least, not for everyone. There are a lot of challenges, from the storage and shipping of different vaccines to how people receive it. Here's when you can expect the COVID-19 vaccine to be available, who will be vaccinated first, and why.

When will COVID-19 vaccines be ready for distribution?

Now that Pfizer and Moderna have applied for EUAs, the FDA has to assess their applications and analyze their data to ensure the vaccines are as safe and effective as the companies have reported. Typically that process can take "between three and four months, maybe even longer," FDA commissioner Stephen Hahn, M.D. told ABC News. But, in an effort to distribute vaccines as quickly as possible while COVID-19 infections hit all-time highs in the U.S., Dr. Hahn said the FDA is aiming to complete the EUA authorization process in about three weeks. In his interview with ABC News, he assured people that "vigorous standards are being enforced" during the FDA's review, regardless of the timeline. "In terms of setting the appropriate expectations, we are balancing the public health emergency we're facing and the fact that people are getting sick with COVID with the need to get this right," he said. (

Once a vaccine gets its EUA, federal officials say the goal is to begin distribution as soon as 24 hours later, reports USA Today. Local health officials will need to request that their immunization programs receive doses of the vaccine, meaning once a EUA is authorized, distribution is largely up to state and local governments, not federal officials, to carry out, according to the Kaiser Family Foundation.

One major hurdle to distribution is the storing and handling of the vaccines themselves. While Moderna's vaccine can be delivered and stored in a regular medical refrigerator (which provides temperature-controlled airflow, storage, and distribution needed for things including vaccines, blood for transfusions, etc.), Pfizer's requires special freezers with extremely cold temperatures (-94 degrees Fahrenheit — colder than winter in Antarctica), according to Reuters. That means Moderna's vaccine will likely be readily available at places such as doctors' offices and pharmacies, but Pfizer's may only be available at specific vaccination sites that have access to freezers cold enough to store the vaccine. "This will affect distribution, as facilities, and even areas of the world that do not have access to these freezers, may not be able to distribute the Pfizer vaccine," says Purvi Parikh, M.D., an allergist and immunologist at Allergy & Asthma Network.

So far, Britain is the first country to grant emergency authorization of the Pfizer vaccine, and they're expected to start administering doses as soon as next week, according to the New York Times. But as vaccine distribution reaches an international scale, those special freezers required for Pfizer's vaccine will become more sought-after, similar to what we saw with personal protective equipment (PPE) and ventilators earlier in the pandemic, reports The Washington Post. Health-care companies and hospital systems are currently ramping up to meet the demand, according to the publication, but time will tell whether that detail limits Pfizer's distribution of the vaccine, thus potentially putting pressure on other vaccine candidates to increase their distribution.

Another challenge concerns the dosing of the vaccine. Both Pfizer's and Moderna's vaccines require two doses. You'll need to wait three weeks between the two shots for Pfizer's vaccine, and four weeks between shots for Moderna's, according to The Washington Post.

"Having two doses may be a huge deterrent," says Dr. Schwartz, noting that people may simply not be diligent or willing enough to return for the second dose. That issue could be compounded by the fact that initial reports suggest the side effects of these vaccines, while not serious, can be "unpleasant," which could lead people not to come back for a second dose, according to NBC News.

"All people need to get both doses, not only to be vaccinated fully and gain immunity but also because having only one dose could be dangerous in that those people can potentially still catch COVID-19 and spread it to others," explains Dr. Parikh.

Who will get the COVID-19 vaccine first?

You can expect all COVID-19 vaccines that receive emergency authorization in the U.S. to be in limited supply, at least in the beginning stages of the administration, according to the Centers for Disease Control and Prevention (CDC). As supply chains catch up to demand, the number of available vaccines will eventually "increase in the weeks and months that follow" vaccine authorizations, according to the agency.

Given the limited supply coupled with risk factors, health officials are recommending that some people get vaccinated before others.On December 1st, the CDC's Advisory Committee on Immunization Practices (ACIP) announced that once a COVID-19 vaccine receives emergency authorization, it will recommend that health care workers and residents of long-term care facilities (such as people in nursing homes) be vaccinated first, due to their increased exposure to the virus and risk of severe complications if infected. (

Beyond that, the ACIP is currently considering a few different proposed frameworks for the order in which subsets of people might receive a COVID-19 vaccine — and so far, nothing is confirmed. Here's a glance at one suggested four-phased framework from the National Academies of Sciences, Engineering, and Medicine:

• Phase 1a: First responders and high-risk health workers in hospitals, nursing homes, and home care, including those who provide health care facility services such as transportation. This group makes up about 5 percent of the U.S. population.
• Phase 1b: Older adults (age 65 and up) in "overcrowded settings" such as nursing homes, long-term care facilities, homeless shelters, group homes, and prisons, as well as people of all ages with underlying conditions (such as cancer, serious heart conditions, and sickle cell disease) that put them at "significantly higher risk of severe COVID-19 disease or death." This group accounts for about 10 percent of the population.
• Phase 2: K-12 teachers, school staff, and child care workers. "Critical workers in high-risk settings" (think: grocery store and other food supply workers and people who work in public transit) will also be included, along with people of all ages in overcrowded settings like homeless shelters, group homes, and prisons. Additionally, this phase includes people of all ages with underlying conditions that put them at "moderately high risk" of severe COVID-19 infection (including type 2 diabetes, chronic kidney disease, and obesity, among other conditions). This group makes up about 30-35 percent of the population.
• Phase 3: Young adults (age 18-30), children, and workers in industries that are "important to the functioning of society and at increased risk of exposure not included in Phase 1 or 2" (such as colleges and universities, hotels, banks, exercise facilities, and factories). This covers about 40-45 percent of the population.
• Phase 4: Everyone else in the U.S. who didn't have access to the vaccine in previous phases.

While this entire process could begin as early as mid-December, experts say that the majority of the general public probably won't have access to a vaccine until around spring of 2021, at the earliest.

In the meantime, keep wearing your mask around others outside your home, continue practicing social distancing, and stay on top of your handwashing habits. Even once a vaccine is ready, the CDC says all of these strategies will remain crucial in protecting everyone from and slowing the spread of COVID-19.

The information in this story is accurate as of press time. As updates about coronavirus COVID-19 continue to evolve, it's possible that some information and recommendations in this story have changed since initial publication. We encourage you to check in regularly with resources such as the CDC, the WHO, and your local public health department for the most up-to-date data and recommendations.