While the Food and Drug Administration granted full approval to Pfizer’s COVID-19 mRNA vaccine on Aug. 23, officials are now asking the White House to scale back the plan to administer vaccine boosters until the Centers for Disease Control and other health organizations can thoroughly review the data. Over 200 million doses of the Pfizer vaccine have been administered in the United States since December, and though most clinical trials can last years before being granted full FDA approval, the FDA is confident in the efficacy and safety of this vaccine after months of real-world trials.


Jessica Merricks, assistant professor of biology.
What do vaccines like those for COVID-19 do? What do they not do? 

“While vaccines vary in terms of the way they are made, their ultimate goal is to help us build a defense against a virus. The three vaccines being administered around the country (Moderna, Pfizer, and Johnson & Johnson) teach our bodies to create a protein that looks like part of the virus. When our immune system comes across this protein in our blood, it initiates our body’s natural defense system, producing antibodies that will protect us if the real virus ever enters our body. The result: our body knows exactly how to fight COVID-19, meaning we will experience little or no mild/moderate symptoms of the disease, and no severe or life-threatening effects.”


What does the vaccine development process look like in the United States?

“There are several broad stages involved in vaccine development. The process involves lab and animal studies, clinical studies with human subjects to assess safety and immune response, regulatory approval processes, scaling up and manufacturing the vaccine and post-approval monitoring of potential side effects.”


What does FDA approval mean for the efficacy and safety of a vaccine?

“Essentially, when the FDA approves a vaccine, it means that through rigorous testing and regulatory oversight the benefits of the use of the vaccine have been shown to outweigh the risks of its use. It suggests that the public can be confident that the vaccine meets high standards for safety and effectiveness.”


What requirements does a vaccine need to satisfy to gain FDA approval?

“The lab producing the vaccine must conduct rigorous lab, animal and human clinical testing and submit their data to the FDA for review. In the case of the COVID-19 vaccines, efficacy standards for clinical trials were set at 50% or greater. If the FDA determines that the vaccine lowers the risk of a particular outcome (e.g. confirmed COVID infection, severe infection, hospitalization, death, etc.) by 50%, then the vaccine can move forward in the approval process. In the case of the COVID-19 vaccines, the FDA considers updated data from the clinical trials that led to Emergency Use Authorization, as well as post-authorization safety surveillance data (which reports adverse reactions and side effects) prior to making its final decision.”


Who is responsible for regulating vaccine approval?

“The Center for Biologics Evaluation and Research, an arm of the Food and Drug Administration’s (FDA), is responsible for regulating vaccines in the United States.”


How will FDA approval of COVID-19 vaccines impact inoculation rates across the country?

A: “FDA approval will likely have significant impacts on vaccination rates in the U.S. On the one hand, some national surveys have indicated that more people will be willing to get vaccinated once full FDA approval is complete. In addition, FDA approval may open the door for some employers to mandate vaccination of their employers. On the other hand, there are many people who still do not feel comfortable getting vaccinated for various reasons, so FDA approval is unlikely to change their minds.


How long does it typically take for a vaccine to gain approval?

“Typically, it takes 10-15 years for a vaccine to gain approval and make it to market. When the FDA approves a drug for Emergency Authorization Use (EAU) however, some stages can be completed simultaneously which dramatically reduces the length of the process.” 


What do you want students to know about vaccine approval?

“FDA approval is an important milestone in our journey toward ending the pandemic. I hope the approval gives those who are hesitant about getting vaccinated the confidence to accept these safe and effective vaccines.”