We've Moved

Visit our new website at Science.Feedback.org for scientific verifications of viral claims.

COVID-19 vaccines received Emergency Use Authorization from the FDA after clinical trials demonstrated that they are safe and effective; COVID-19 vaccines aren’t experimental

“Not one [COVID-19] vaccine is FDA approved. [...] They are all experimental.”
Misleading: Many vaccines are tested for safety and efficacy, and some vaccines are proven to be effective against disease even if they haven’t been approved by the FDA. Three COVID-19 vaccines have received Emergency Use Authorization from the FDA, which is better suited to ongoing health crises such as the COVID-19 pandemic than standard approval process.
Emergency Use Authorization (EUA) is a fast-track process for approving vaccines and drugs when their benefits outweigh the potential risks to a population. EUA is well-suited for addressing ongoing global health threats, such as the COVID-19 pandemic. Three COVID-19 vaccines received EUA from the FDA, after clinical data showed they were effective at protecting vaccinated individuals against the disease and had few risks for the general population. Continued monitoring of vaccinated populations is a standard procedure to increase our knowledge about a vaccine’s benefits and risk in a real world setting.

FULL CLAIM: “Not one [COVID-19] vaccine is FDA approved. [...] They are all experimental. You are in the experiment”


The rapid development of COVID-19 vaccines allowed the U.S. to initiate a nationwide campaign of vaccination against the disease in December 2020. More than 138 million vaccine doses were administered as of 24 March 2021. U.S. president Joe Biden set a goal of administering 200 million doses by the end of April 2021 to stop a pandemic that caused more than 550,000 deaths in the country as of 30 March 2021.

Social media posts, such as this one, claimed that COVID-19 vaccines are experimental and didn’t receive approval by the U.S. Food and Drug Administration (FDA), which is the federal agency responsible for vetting and approving of drugs and vaccines. These claims implied that the safety and efficacy of COVID-19 vaccines haven’t been demonstrated yet. However, this is misleading as it fails to mention that the vaccines were authorized for emergency use only after they were shown to be safe and effective during clinical trials.

COVID-19 are authorized for emergency use following a careful review of their benefits and potential risks

Three COVID-19 vaccines are authorized for use in the U.S. as of 29 March 2021. The Pfizer-BioNTech vaccine was authorized by the FDA on 11 December 2020, the Moderna vaccine on 18 December 2020, and the Johnson & Johnson vaccine on 27 February 2021. All three vaccines received the Emergency Use Authorization (EUA), which is distinct from FDA approval.

The FDA describes the EUA concept as follows:

“Under an EUA, FDA may allow the use of unapproved medical products, or unapproved uses of approved medical products in an emergency to diagnose, treat, or prevent serious or life-threatening diseases or conditions when certain statutory criteria have been met, including that there are no adequate, approved, and available alternatives.”

This description illustrates that the EUA is specifically designed to address serious public health threats, such as that posed by the COVID-19 pandemic, when a swift reaction is needed. An EUA can only be issued if the government declares a public health emergency, as was done by the U.S. Secretary of Health and Human Services on 31 January 2020. An EUA is limited and ends when the declaration of a public health emergency is terminated or revoked.

Importantly, any drug or vaccine candidate under consideration for the EUA must have undergone clinical trials. Specifically, the FDA requires data from Phase I, Phase II and Phase III clinical trials that demonstrate the safety and efficacy of the vaccine in order to issue an EUA for a vaccine. The data are then reviewed by a panel of leading vaccine and infectious disease experts who determine whether the benefits of the vaccine outweigh its risks. The FDA made the biological and clinical data for the Pfizer-BioNTech, Moderna, and Johnson & Johnson vaccines publicly available. These data highlighted a vaccine efficacy of 95%, 94.5% and 66.9%, respectively.

The clinical trials also established the safety of those vaccines. The majority of observed adverse events are mild and transient and characteristic of the body’s reaction to vaccination. They include redness and pain at the site of injection, fever or headache. The clinical trials on the Pfizer-BioNTech, Moderna and Johnson & Johnson vaccines all showed that serious adverse events were extremely rare (below 1% of the number of volunteers) and occured in the same proportion between the volunteers who received the vaccine and those who didn’t (control group). This strongly suggests that none of the serious adverse events observed during the trials were caused by the vaccine.

There are indeed differences between FDA approval and an EUA. In an article published by The Conversation, Christopher Robertson, a professor of law at Boston University and Jeremy Greene, a professor of medicine at Johns Hopkins University explained that FDA approval usually requires two Phase III clinical trials and a longer follow-up than an EUA.

However, the FDA approval process for a vaccine isn’t practical in the face of a serious health threat that is causing excess mortality. As such, the process for granting an EUA evaluates whether a product’s benefits outweigh the risks, whereas FDA approval focuses solely on the proof of safety. In the case of the three authorized COVID-19 vaccines, clinical trials and post-authorization monitoring showed that risks are very small, the majority of reported adverse events being mild and transient and characteristic of vaccination.

According to the University of North Carolina Health Care, the EUA also speeds up the manufacturing process for vaccines by allowing companies to scale-up production in parallel with the clinical trials. During a standard FDA approval, clinical trials would be conducted before scaling up production, delaying the availability of the vaccine to the general public.

The use of the EUA is not new, as several EUAs have been issued in the past. For instance, the U.S. Secretary of Health declared an emergency in 2005 due to a heightened risk of anthrax contamination of military personnel. This led the FDA to issue an EUA for an anthrax vaccine by EUA from 2005 to 2006. Several other EUAs for products pertaining to other public health concerns, such as Ebola, remain active.

Continued monitoring following authorization is a standard procedure and doesn’t mean that the vaccines are experimental

The Facebook post also claimed that COVID-19 vaccines are experimental and seemed to imply that people who received the vaccines are “in the experiment”. This claim is inaccurate and misleading, as it suggests that people who received the vaccine are guinea pigs for the vaccines and that the vaccines’ safety and efficacy aren’t established.

Although the COVID-19 vaccination campaigns are continually monitored by health agencies, the fact that new data is being collected after the vaccines were authorized doesn’t mean that the vaccine is experimental. Rather, the goal is to increase our knowledge of how the vaccine works and ensure that it is indeed effective in the real world.

This continued gathering of data is helpful, as certain populations were excluded from the initial clinical trials. For instance, the Phase III Pfizer-BioNTech trial excluded volunteers younger than 18 and pregnant women. Although the mechanism of the vaccine and data from the initial clinical trials don’t indicate grounds for concern in pregnant women and children, additional studies were planned in order to gather more data in these specific groups. These studies will enable researchers to better evaluate the vaccines’ safety and efficacy. An ongoing clinical trial is investigating the efficacy and safety of the Pfizer-BioNTech vaccine on pregnant women, while a trial of the Moderna vaccine is underway in children.

Finally, a newly approved or authorized vaccine enters into the Phase IV trials, which examine the effects of the vaccine in the real world. Phase IV trials monitor the population that received the vaccine[1] and determine whether the vaccine provided the same benefits observed in earlier stages of clinical trials.

For instance, the ongoing monitoring of the Israeli population showed that the Pfizer-BioNTech vaccine was 94% effective against symptomatic cases of COVID-19[2]. The researchers concluded that this result is consistent with that of the initial clinical trials[3].

Another study of more than 110,000 individuals in Israel revealed that the viral load was lower in patients who became infected after their first vaccine dose (when the vaccine protection wasn’t complete yet) compared to their non-vaccinated counterpart[4]. A similar post-authorization study of U.S. healthcare workers who were vaccinated showed that the COVID-19 RNA vaccines are 90% effective against infection, similar to the results obtained during clinical trials.

In summary, the COVID-19 vaccines available in the U.S. aren’t experimental, as they were shown to have met the FDA’s requirements for safety and efficacy. The vaccines benefited from a fast-track process in which the balance between the potential risks and benefits is carefully assessed in the context of the ongoing health crisis. The vaccines continue to be monitored after their authorization as part of the usual process for new drug release to improve our understanding of its effects and to ensure their safety.



Published on: 31 Mar 2021 | Editor:

Health Feedback is a non-partisan, non-profit organization dedicated to science education. Our reviews are crowdsourced directly from a community of scientists with relevant expertise. We strive to explain whether and why information is or is not consistent with the science and to help readers know which news to trust.
Please get in touch if you have any comment or think there is an important claim or article that would need to be reviewed.