Two potential vaccines are in the final stretches of an unprecedented regulatory sprint to be approved for sale and distribution to billions of people worldwide. Pfizer and its partner BioNTech are currently in the lead with their mRNA vaccine, which was found to be 95 percent effective in Phase 3 clinical trials and was granted authorization by the U.K.’s Medicines and Healthcare Products Regulatory Agency (MHRA) on December 2. Pfizer has submitted its emergency use authorization (EUA) application to the FDA and could receive authorization for sale in the U.S. in the next few weeks, after the FDA holds an advisory committee meeting regarding the vaccine on December 10.

Close on Pfizer’s heels is Moderna and its 95 percent effective vaccine, which has its FDA advisory committee meeting on December 17. Trailing behind both is AstraZeneca, which has reported Phase 3 clinical trial results of 90 percent and 62 percent effectiveness, depending on the dose pattern used. This race to quickly provide a safe and effective COVID-19 vaccine has put the FDA and its EUA regime in an unwanted spotlight.

Unlike other health-related items regulated by FDA, such as drugs and medical devices, biological products and particularly vaccines have been the subject of growing consumer skepticism — and misinformation — for many years. While this article will not wade into the debate between the medical community and “anti-vaxxers,” the breadth of such skepticism regarding vaccines in general provides important context for any discussion of the approval and release of any COVID-19 vaccines.

Regardless, due to the nature of vaccines, it is critical that FDA assure that these biological products be demonstrated to be safe and effective. To that end, FDA requires that vaccines undergo a rigorous and extensive development program, from laboratory creation through numerous animal studies and then human clinical trials, to determine their safety, efficacy, purity and potency prior to approval. In addition, FDA performs on-site inspections and audits of the manufacturing facilities, procedures and quality controls related to these new biological products. This arduous approval process often takes years to complete.

The problem with a raging global pandemic that threatens the health of millions and the economies of the world is that a vaccine simply can’t wait that long. FDA is thus faced with the unenviable task of providing the pathway for industry to quickly develop and market a vaccine while still assuring that such products are as safe and effective as possible — and in which the public has confidence to receive them.

Fortunately, the EUA system was developed several years ago specifically to deal with such global threats. The current structure was created pursuant to and following the 2006 Pandemic and All Hazards Preparedness Act to develop countermeasures for chemical, biological, radiological, and nuclear (CBRN) threats posed by nature or hostile parties.

Under this authority, the FDA commissioner may allow unapproved medical products to be used in an emergency to diagnose, treat, or prevent serious or life-threatening diseases or conditions caused by CBRN threat agents when there are no adequate, approved, and available alternatives.

Under this EUA, these vaccines will not — and cannot — go through the same scrutiny that FDA uses for the same biological products in a normal review. There simply isn’t time. Thus, the purpose of the EUA is to provide an adequate review to assure some level of safety and effectiveness while still getting the potentially life-saving vaccine widely distributed as soon as possible.

To adequately assure safety and effectiveness, FDA still requires a robust three-phase clinical study with the EUA, with tens of thousands of participants. These studies first assess the safety of the vaccine using a small number of healthy recipients; if successful, a larger Phase 2 randomized-controlled study with hundreds more demographically diverse participants. Phase 3 studies are even larger and more diverse, with thousands of participants from broad demographic groups that mimic the intended population of recipients. Successful Phase 3 studies provide the requisite validity for safety and effectiveness of the vaccine itself.

Although these multi-phase studies are similar to those required for “regular” vaccine approval, the timeline is quite compressed, generally requiring only two months of follow-up for Phase 3 participants prior to submitting an EUA request. Other significant differences related to the EUA process is that FDA will not perform a pre-approval inspection of the manufacturing facilities, instead relying on its review and evaluation of detailed process performance qualification testing data to validate that critical process and quality controls are in place. In addition, manufacturers must provide detailed description of facilities and equipment used.

Obviously, supply chain and logistical information for the manufacturing and distribution of billions of doses of vaccines in the next year is of great importance. EUA applicants must also provide detailed information regarding their supply chain for FDA to evaluate anticipated availability of the vaccines if approved. This information includes whether the manufacturer will supply the vaccines to the U.S. government or use its own vendor managed inventory system to control supply. Similarly, manufacturers must provide details for its distribution plans to get vaccines properly distributed as soon as possible.

The fact that we are possibly weeks away from public distribution of COVID-19 vaccines less than 10 months after work began is nothing short of amazing. This pandemic has provided the toughest test of FDA’s EUA system to date. If the candidate vaccines obtain EUA approval and remain as safe and effective as shown thus far, then this EUA system will have proven itself and may save millions of lives worldwide.

Lee Gray is a partner at Holland & Hart LLP focused on the manufacturing and food & beverage sectors. Reach him at The statements made are provided for educational purposes only and do not constitute and should not be taken as legal advice. The opinions expressed do not necessarily reflect the views of Holland & Hart LLP or any of its attorneys other than the author.