Know the Vaccine Development and Approval Process
Vaccine development and approval is an extensive, phased process that, under normal circumstances, takes years to complete. COVID-19 vaccines were developed at unprecedented speeds, without compromising safety, because governments and developers prioritized vaccine candidates over other medications in development to meet the needs of the worldwide community.
The graphics below compare the typical vaccine development and approval process with the process that is taking place during the COVID-19 pandemic to demonstrate how the vaccines are being made available quickly without skipping safety steps along the way.
Typical Process
6+ Years
Scientists Develop Vaccine Candidates
Phase 1 Clinical Trial
Phase 2 Clinical Trial
Phase 3 Clinical Trial
Review by FDA Vaccines and Related Biological Products Advisory Committee (VRBPAC)
Biologics License Application (BLA)
CDC Advisory Committee on Immunization Practices (ACIP) Recommendation
Manufacturing
Distribution
Phase 4 Safety Monitoring
COVID-19 Vaccine Process
12-18 months
Hover over the boxes below to learn more about the step in the process.
Manufacturing
Scientists Develop Vaccine Candidates
Phase 1 Clinical Trial
Phase 2 Clinical Trial
Phase 3 Clinical Trial
Review by FDA Vaccines and Related Biological Products Advisory Committee (VRBPAC)
FDA Emergency Use Authorization (EUA)
CDC Advisory Committee on Immunization Practices (ACIP) Recommendation
Allocation and Distribution
Phase 4 Safety Monitoring
Biologics License Application (BLA)
Inspired by Hackensack Meridian Health
Vaccine Development
How is it possible that COVID-19 vaccine candidates were developed so quickly?
- SARS-CoV-2, the virus that causes COVID-19 disease, may be new, but coronaviruses are not. COVID-19 is similar to the coronaviruses responsible for Severe Acute Respiratory Syndrome (SARS) and Middle East Respiratory Syndrome (MERS), so scientists were able to leverage previous research on coronaviruses, other viruses, and various vaccine technologies to identify dozens of vaccine candidates quickly.
- mRNA and viral-vector technologies benefited from over 15 years of experience in oncology clinical trials and infectious disease clinical trials.
- Unprecedented financial support from governments around the world empowered scientists to tap into innovative vaccine technologies and remove the financial risk normally involved in vaccine development. This allowed some required steps to be conducted simultaneously, which greatly speeded up the timeline.
- The sheer number of COVID-19 vaccine candidates evaluated is another reason we were able to have EUA-authorized COVID-19 vaccines available to the public in record time. More than 50 COVID-19 vaccine candidates are in human clinical trials around the world, and several times as many are in preclinical testing, where vaccine candidates are under investigation in animals or laboratory studies.
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Quick Tip
How can pharmacists respond to patients who express concerns about potential conflicts of interest driving recommendations?
Vaccine Approval
How was it possible for these COVID-19 vaccines to be distributed so quickly?
- Governments took the financial risk. Under normal circumstances, clinical trials follow a step-by-step process designed to balance safety and scientific progress with prudent financial investment by developers. Because of the overwhelming pandemic emergency, governments took financial risks to fund the trials and the early manufacturing of promising vaccine candidates. If the vaccine candidates had failed, the government resources might have been wasted and the products discarded. In fact, the clinical trials were successful at preventing COVID-19 disease, which has been confirmed with real-world evidence.
- Process improvements. FDA has allowed for some steps in the vaccine development process to be conducted at the same time (simultaneously, rather than in series), but no steps were omitted.
- Lots of people volunteered for the clinical trials quickly. It often takes a lot of time to recruit people for clinical trials. Because the COVID-19 pandemic was spreading rapidly, millions of volunteers were willing to quickly sign up for the clinical trials.
Learn More
Review FDA’s infographic that explains how time was saved. Hear from the pharmacist who helped develop the infographic, Susan Winckler, RPh, Esq., CEO of the Reagan-Udall Foundation for FDA, beginning at minute 29:20 during this APhA Open Forum webinar.
Were clinical trials of COVID-19 vaccines conducted differently?
Each vaccine goes through three phases of clinical trials before licensure and FDA review. Safety monitoring by FDA, CDC, and its health care partners continues in a fourth phase of the vaccine life cycle. As described above, these phases typically take several years, largely to steward the resources needed to bring a vaccine to the public. During the pandemic, developers still conducted all three phases of clinical trials (e.g., 40,000 volunteers in Phase 3 trials) and were empowered to conduct some of the work simultaneously.
- Phase 1: Emphasis is on assessing safety while considering immune response in a few dozen otherwise healthy volunteers who haven’t been exposed to the virus.
- Phase 2: If no safety concerns arise during Phase 1 studies, Phase 2 studies include more people. Various dosages are tested on a few hundred people with varying health statuses and demographic groups. These studies provide additional safety information, as well as preliminary information on effect (ability to generate antibodies or cellular immune responses).
- Phase 3: If no safety concerns arise during earlier phases, the vaccine is administered to several tens of thousands of people. Vaccine studies are some of the largest clinical trials—typically 20,000 to 40,000 in Phase 3 vaccine studies. These studies generate pivotal information on effectiveness (ability to prevent disease) and additional important safety data on less common adverse events.
- Phase 4: After FDA grants a vaccine permission for widespread use under EUA or a product license, monitoring continues throughout the product’s usage. Additional analysis is done regarding coadministration with other vaccines, use in other age groups, etc.
Learn More
Watch COVID-19 Vaccine Clinical Trial Process Open Forum Webinar from APhA’s Open Forum Webinar series. (Slides)
How is an Emergency Use Authorization different than the usual vaccine licensure process?
During a typical vaccine license process, a developer submits a biologics license application (BLA) to FDA. The FDA often seeks independent, external advice from its Vaccines and Related Biological Products Advisory Committee (VRBPAC). During a public health emergency, such as the current pandemic, FDA can issue an emergency use authorization (EUA) to facilitate the availability of various products. An EUA is a regulatory option for a vaccine once the developer has accumulated enough scientific evidence for efficacy, safety, and product quality. The EUA only lasts during the emergency and is reviewed by the FDA periodically. Later, the developer must seek full approval via BLA as they achieve certain data targets.
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Quick Tip
What should pharmacists know about full vaccine approval and how it differs from emergency use authorization?
What is the role of the CDC’s Advisory Committee on Immunization Practices (ACIP)?
CDC’s Advisory Committee on Immunization Practices (ACIP) is a group of independent medical and public health experts who carefully review all available data about the vaccine from clinical trials and other studies to develop recommendations for vaccine use. The ACIP advises the CDC Director.
Print for Patients
CDC’s How a COVID-19 Vaccine is Recommended for Public Use.
Ongoing Safety Monitoring
What ongoing safety monitoring is being conducted with COVID-19 vaccines?
CDC expanded its usual safety surveillance programs to monitor COVID-19 vaccines, as well as adding new systems and additional information sources. Pharmacists should be aware of these systems and contribute their clinical experiences by reporting adverse events. Expanded or new safety monitoring systems include:
- Vaccine Adverse Event Reporting System (VAERS): The nation’s early-warning system that collects reports of adverse events that happen after vaccination. VAERS can generate signals but cannot assess causality (i.e., cause-and-effect relationship with vaccination).
- CDC’s National Healthcare Safety Network (NHSN): An acute care and long-term care facility monitoring system with reporting to the Vaccine Adverse Event Reporting System (VAERS).
- CDC and FDA Vaccine Safety Datalink (VSD) and other large insurer/payer databases: A system of administrative and claims-based data for surveillance and research. VSD offers some of the more scientifically powerful ways of assessing whether any particular adverse event is associated in a cause-and-effect way with vaccination.
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