Since Pfizer and our collaboration partner, BioNTech, began our mission to develop a COVID-19 vaccine, safety has been our guiding principle every step of the way.
At the same time, given the urgency of the global pandemic, we continue to move at record-breaking speed. We recently started the phase 2/3 safety and efficacy trial for our lead vaccine candidate, approximately three months after we started the phase 1/2 safety and immunogenicity trials in Germany and the United States for our four initial vaccine candidates. Progressing from the start of clinical testing for a vaccine candidate in small numbers of trial participants to a large-scale efficacy trial is a process that can usually take years, sometimes even a decade.
How have we managed to compress the timeline, while maintaining our high standards of safety? Simply put, we know how to navigate the complex and challenging process of vaccine development and our deep history shows it. For well over a century, Pfizer has been at the forefront of helping to reduce the threat of deadly infectious diseases through the development of novel vaccines and medicines based on new delivery systems and technology. In 2000, we were the first to license a 7-valent pneumococcal vaccine for infants and young children. We have six approved vaccines in our portfolio, deployed in more than 160 countries. And today, our thousands of colleagues around the world globe are marshaling their expertise to rise to this unprecedented challenge.
Read on to learn more about some of the key factors driving the safety and speed of our vaccine development.
We are building upon an existing collaboration
In March, when we launched our collaboration with BioNTech to develop a COVID-19 vaccine, we already had an existing relationship with the German biotech company, which had advanced novel mRNA platforms. Since 2018, we’ve been collaborating to develop mRNA vaccine technologies for potential influenza vaccines. “We already had processes in place, so we were able to implement those quickly for COVID-19,” says Phil Dormitzer, Vice President and Chief Scientific Officer for Viral Vaccines at Pfizer.
We are designing a unique safety and efficacy trial
Our phase 1/2 trials, which examine the safety, immunogenicity, and optimal dose level of our investigational mRNA vaccines, tested four vaccine candidates. Vaccine developers usually move only one candidate into human testing. Testing four candidates in parallel helps to shorten the amount of time it takes to gather necessary data and sift out a lead candidate.
Our process includes outside safety experts
In addition to our own safety experts, our COVID-19 vaccine trial is being overseen by an independent data monitoring committee (DMC), an outside group of experts who closely monitor patient safety and efficacy during the study. “We take their advice very seriously,” says Alejandra Gurtman, Vice President of Vaccine Research and Development at Pfizer. These outside experts can make recommendations whether the study should be changed or stopped due to safety concerns.
We are collaborating at unprecedented levels
Working closely with academic and industry experts around the globe, scientists are using every resource at their disposal to accelerate steps in vaccine development. One example is the sharing of knowledge and expertise related to serology assays. These blood tests are critical to measuring the immune response after vaccination. Thanks to close collaborations with outside partners, our scientists were able to quickly adapt to rapidly enable serology testing for SARS-CoV-2, some of which must be done at special labs having high levels of biocontainment.
We are working closely with the FDA
In the usual drug development journey, the process of preparing regulatory data packages to submit to the FDA and then waiting to hear back is typically iterative and time consuming, often taking months. With all hands-on-deck in the fight against COVID-19 across the globe, regulators are responding to data very quickly, often in real time, to help keep trials running as quickly as possible.
We are leveraging our vast experience, heritage and infrastructure
We have a long track record in vaccine development, including extensive experience in running large phase 3 clinical trials, working closely with regulators, and scaling up manufacturing. “This is what we do for a living,” says Dormitzer. “We have all the infrastructure in place to run large studies and to manufacture large quantities of vaccines and medicines.” For example, as we’ve scaled up to our phase 2/3 study, we’re able to turn to existing networks with testing sites to quickly recruit participants.
Our trial is moving to phase 2/3
In the final phase, we plan to give our potential vaccine to up to 30,000 participants to test its efficacy and safety. The number of participants who will be observed after immunization to assess vaccine safety will be the same number usually required by the FDA to license a vaccine under non-emergency circumstances. Researchers are looking for evidence that subjects are protected against COVID-19. “We will have a standard large safety database and fully statistically rigorous determination of efficacy,” says Dormitzer. “The trial will continue until we get that, and we estimate that by fall we could have enough data to determine if the vaccine works or not,” he adds.