With the ever-growing list of COVID-19 vaccine candidates, developers are moving onto the next step in the process: emergency use authorization (EUA). Following the approvals, it is only then that officials can deploy the vaccines to the citizens of different countries. However, early deployment of vaccines could lead to consequences given that the vaccine trials are still ongoing, and thus all the possible effects of the vaccines cannot be known.
The Pfizer and BioNTech, and Moderna vaccines applied for EUA in numerous countries. The U.S Food and Drug Administration (FDA) approved the Pfizer vaccine for EUA late last week.
Pfizer and BioNTech’s BNT162b2 is based on messenger ribonucleic acid (mRNA) immunotherapy. Developed through a computational approach, it creates a unique bioinformatic profile of mutation patterns with mRNA particles for the immune system to grow resistance.
Similarly, Moderna’s mRNA-1273 instructs the body to create the coronavirus spike protein to enable the immune system to recognize COVID-19 and learn how to make an antibody to fight it.
Both vaccines are 95 percent effective based on clinical trials.
What Is an Emergency Use Authorization (EUA)?
The U.S. FDA regulates the safety, effectiveness and quality of vaccines. The agency provides an evaluation through all phases of the clinical trial process and approves the vaccine for emergency use. The EUA enables developers to make a vaccine available during public health emergencies.
Before submitting an EUA application, developers must conduct clinical trials with thousands of volunteers to determine the safety and effectiveness of their vaccines. There are three phases in each clinical trial. The first phase is to test the vaccine on a small number of healthy people at an increasing dose to see if the vaccine triggers an immune response. In the second phase, the vaccine is given to more people of various health statuses to analyze short term side effects and risks. Finally, in the third phase, a vaccine and placebo are given to two separate groups consisting of thousands of people to provide data on effectiveness and safety. The FDA then gathers the information and compares the risks and benefits of deploying the vaccine.
During a pandemic, the government may partner with agencies, international counterparts, academia, nonprofit organizations, and pharmaceutical companies to speed up the development of the best vaccine candidates as well as make investments into manufacturing and distributing them.
What Are the Challenges Surrounding Emergency Authorized Vaccines?
Developers have started to distribute the COVID-19 vaccines starting with China, Russia and the United Arab Emirates, which administered the vaccines before the clinical trials ended. The United Kingdom and United States did so also following the results from phase three trials.
Indeed, the vaccine will not be subject to the same informed requirements for clinical investigations due to the pandemic. In fact, there is not enough long-term data to establish information such as whether the vaccine prevents infection, how long the vaccine protection lasts, and how well these vaccines work on people who are at high risk of contracting the virus.
The outcomes of trials for both the Pfizer and Moderna vaccines are only two months following the participant’s last dose, as mandated by the FDA. According to an article in The New England Journal of Medicine, a patient shows the effects of a vaccination after six weeks, and a two-month follow-up will show if the immune system creates an antibody for the vaccine. However, the FDA generally requires at least six months for the clinicians to follow up to see if any serious health issues were caused by the vaccine. Since the technologies used to prevent COVID-19 have not been used in previously licensed vaccines, many argue that a longer safety follow-up will show concrete evidence of any safety issues.
For example, participants in Shingrix clinical trials for a shingles vaccine had a follow-up after 3.1 years on average and 3.9 years in another trial. In the Zostavax clinical trials, the clinicians had a follow-up after 1.3 years in one study and 3.1 years in another.
Once a vaccine is approved, the participants in the placebo-controlled group might receive the vaccine, which means that the company would not be able to effectively compare the long-term effects of the people who received the vaccine to those who did not. The best quality of information will only be available if clinicians can continue to compare the two study groups.
Both companies say they will monitor participants for two years after their final vaccine dose to gather safety and efficacy data. They will monitor both the vaccine and placebo groups, and those who received the placebo but crossed over to the vaccine group, separately to compare the data between them.
According to the FDA, it has issued the first EUA to allow the Pfizer-BioNTech COVID-19 vaccine to be distributed across the county. Now, the U.S. Centers for Disease Control and Prevention (CDC) will set forth its distribution list of who will receive the vaccinations and when. Following the approval of the vaccine, the FDA, the CDC, and health care delivery companies will monitor the safety of the vaccines to detect any arising issues.
Vaccine recipients will receive a fact sheet that describes the investigational nature of the product, the known and potential benefits and risks, available alternatives, and the option to refuse vaccination.