Generating $14 billion from the vaccine alone, Pfizer shares hit a record high of $50.42 in August 2021 for the first time in more than 20 years (4).

Who? 43, 548 healthy male and female participants aged 12-85 [16] 

Where? 155 global study locations spanning six countries (US, Germany, Brazil, Turkey, Argentina and South Africa) [16]
 

When? A 7-month effort, with Phase 1 beginning in May 2020 and Phase 3 reaching its primary analysis in November 2020 [16]

Simultaneous evaluation of various mRNA candidates: Pfizer assessed up to four mRNA candidates simultaneously in Phase 1 and 2 to improve efficiency of evaluation in a greater number of volunteers [16]. 

Rolling data submission: FDA received key portions of the application months in advance compared with when they would in a typical timeline. This gave the FDA the opportunity to begin reviewing and resolving issues sooner, shortening the overall review time.

What does this mean for the future of clinical trials? Hybrid clinical trials make research and development less costly as well improve efficiency and the time needed to set-up. This is clearly shown as clinical trial sites were running in weeks, as opposed to months, as there are usually preparations involving locating staff in specific locations for trial monitoring. Furthermore, e-consenting for the trial not only increased the safety of its staff and health care providers, but also improved efficiency. [18] 

Pfizer wanted to ensure they recruited a diverse and representative patient population [16]. This meant selecting the right sites and managing patient recruitment [16]. However, people weren’t signing up in target areas as fast as the companies expected. Pfizer deployed mathematical models to predict COVID-19 hotspots using infection rate and location data, but they weren’t doing a good job at predicting virus hotspots more than a few weeks out.

Ultra-cold storage: Pfizer had to ensure the site was set up to manage temperatures -80 degrees Celsius to -60 degrees Celsius and have monitors on site to ensure that all of the trial protocols were followed. [16]

Ensuring safety in a pandemic: Pfizer had to ensure patient and staff safety, which they did through the use of PPE and other measures. [16]

Primary Endpoints: The number of participants with symptomatic COVID-19 who have not been infected by SARS-CoV-2 prior to immunization, as well as the number of participants with symptomatic COVID-19 regardless of whether participants have previously been infected by SARS-CoV-2. [16]

Secondary Endpoint:  The number of participants with severe COVID-19 in those groups [16]

Results: All primary efficacy endpoints with 95% efficacy. 170 confirmed cases of COVID-19. 162 cases were seen in the placebo group. 8 cases in the vaccine group. [16]

(Roujin et al, 2020)

(Roujin et al, 2020)

1:(Roujin et al, 2020) 2:(Wrapp et al, 2020) 3: (Yuxian et al, 2004)

Luckily for us, the efforts to create a vaccine were not only heavily expedited and incentivized, the process of developing a vaccine may have been revolutionized altogether due to the decades-long effort to bring mRNA vaccines to the forefront of clinical research.

(Joyner et al, 2020)

With the challenges surmounted, the benefits of an mRNA vaccine can stand out:

(Pardi et al, 2018)

(Vogel et al, 2020)

(Vogel et al, 2020)

(Vogel et al, 2020)

All in all, the preclinical trial proved this candidate to be an effective immunizer against COVID-19 and thus it was admitted to clinical trials

(Vogel et al, 2020)

A safe, effective vaccine is urgently needed for children younger than 12 years of age. As of November 9, 2021, a phase 1 evaluation of the BNT162b2 Covid-19 vaccine in children 5 to 11 years of age has been completed. A Covid-19 vaccination regimen consisting of two 10-μg doses of BNT162b2 administered 21 days apart was found to be safe, immunogenic, and efficacious in children 5 to 11 years of age. Phase 2 / 3 is ongoing with 2268 children randomly assigned to receive the BNT162b2 vaccine (1517 children) or placebo (751 children). [19]