Scientists around the world are racing to develop an effective vaccine to protect people from the coronavirus.

Three companies have announced their COVID-19 vaccines have the potential to be at least 90% effective. So far, no vaccines have received approval from the Food and Drug Administration, although some are in the midst of clinical trials. The FDA wants a vaccine to prove it’s at least 50% effective against the virus.

Dr. David Pearce, president of Research, Innovation and World Clinic for Sanford Health, thinks the U.S. will have a vaccine available by the end of 2020.

Learn more: COVID-19 vaccine updates from Sanford Health

After the science has answered its questions, it’ll be up to manufacturing to come up with a substantial number of doses, he said.

“The bigger question is, how do we distribute that vaccine, and how do we convince everybody to have that vaccine?” he says.

David expects Sanford Health, with its extensive network, to be able to distribute a vaccine as quickly as possible. A multidisciplinary group across the health system is working on detailed plans for receiving, storing and administering the vaccine. The same group is planning for who should receive the vaccine first.

To be able to come up with a vaccine in less than a year would be an unusual feat, but the pandemic has been anything but ordinary.

“This is an innovative time,” David says. “Right now, this is a serious pandemic. Many thousands of people have lost their lives. All hands on deck, not taking shortcuts, just 24/7, and lots of people 24/7 throwing their energy and innovation toward this because we’ve got to crack it.”

You may wonder how a vaccine gets developed and then approved. Here’s some basic information about how the vaccine development process works, according to the FDA and the Centers for Disease Control and Prevention. There also are some specific considerations for a coronavirus vaccine.

What is a vaccine used for?

Vaccines offer people immunity from infectious diseases caused by viruses or bacteria that could cause complications, hospitalizations or even death in some populations. Vaccines may prevent people from getting a disease at all, or they may reduce the severity of an illness.

Why are vaccines important?

Vaccines can protect individuals from unpleasant symptoms or dangerous effects of an illness. If a large enough percentage of the population gets immunized, vaccines also have the effect of protecting the people who are unable to be immunized. They can help keep immune-compromised people or young infants from catching a life-threatening disease.

How do vaccines work?

Vaccines contain a part or whole piece of the bacteria or virus they aim to protect against, but in a weakened or inactive form. Vaccines stimulate the body to create immunity that defends against future infection. That means when a person is exposed to the disease later, their body produces an immune response to fight off the virus or bacteria as if they had already had the disease.

How do we know a vaccine is safe?

Before a vaccine can become available for use by the American public, the FDA must approve it first, following a series of successful stages of development. The FDA and CDC then monitor the safety of the vaccine once it is in use. The FDA’s Center for Biologics Evaluation and Research External regulates vaccines in the United States.

How are vaccines usually developed?

Traditionally, vaccines go through a series of stages of development that can take a number of years.

Stage 1: The exploratory stage of basic research, which may take several years.

Stage 2: The preclinical stage, which may involve animal testing.

Stage 3: Clinical trials, which involve humans. This stage, sometimes taking several years, has at least three phases for vaccines and often includes a fourth.

  • Phase 1: This phase gives the vaccine to healthy volunteers and considers questions about safety and side effects.
  • Phase 2: This phase broadens to more volunteers with characteristics similar to the people the vaccine aims to help. It considers questions about safety and effectiveness.
  • Phase 3: This phase involves a large number of volunteers and compares people who received the vaccine to people who didn’t.
  • Phase 4: This phase involves ongoing studies of effectiveness and long-term safety after the vaccine is approved. The FDA can mandate a Phase 4 study.

Stage 4: The regulatory review and approval stage. The FDA approves the vaccine if it’s safe and effective and if the benefits outweigh the risks.

Stage 5: The new vaccine is manufactured in batches called lots.

Stage 6: The quality control stage. Lots are tested by the manufacturer for safety, purity and potency. Then the FDA reviews their safety and quality before they may be distributed. The FDA also conducts inspections of vaccine manufacturing facilities regularly.

What about monitoring after vaccines are in use?

Vaccines are monitored for possible side effects — or adverse events — after they’ve been approved and distributed. Anyone from patients to health care providers can submit reports to the Vaccine Adverse Event Reporting System, which then analyzes them. If reports reveal new information on risks for a vaccine, its recommendations may change.

Do guidelines differ for developing coronavirus vaccines?

No. The FDA released nonbinding recommendations in June specifically addressing the development, approval and manufacturing of vaccines to prevent COVID-19, as the agency considers it a public health emergency.

“While the FDA is committed to expediting this work, we will not cut corners in our decisions and are making clear through this guidance what data should be submitted to meet our regulatory standards,” FDA Commissioner Stephen M. Hahn said when the guidelines were released.

What is emergency use authorization?

Declaring an emergency use authorization would allow a vaccine that hasn’t been approved yet to be distributed — before the end of a Phase 3 clinical trial, for example. Among the requirements to meet an emergency use are a determination that the known and potential benefits of a vaccine outweigh the known and potential risks in preventing a serious or life-threatening disease. For vaccines, an assessment about an emergency use would be considered on a case-by-case basis. However, no new vaccine has ever been released under an Emergency Use Authorization.