Understanding mRNA Vaccines

This article was last updated August 26, 2021. 

In early 2020, as the novel coronavirus spread rapidly across the globe, biopharmaceutical researchers turned to face the challenge head on. Given the pressing need for safe and effective vaccines to help prevent COVID-19, along with the volume of information that remained unknown about the disease, a wide range of approaches to vaccine development were used to improve the odds that one or more of these approaches would be successful. 

“By no means have the last few months been business as usual,” said Advait Badkar, Ph.D., Senior Director, Novel Delivery Technologies at Pfizer, which is one of numerous companies researching a potential COVID-19 vaccine. “We’ve all stepped up to meet this challenge.”

Breaking Barriers With mRNA Technology 

One of the approaches used to develop a COVID-19 vaccine relies on mRNA technology, which can offer greater flexibility and quicker development timelines than traditional vaccine development.

Unlike conventional vaccines, which work by injecting an inactive or weakened pathogen, or part of a pathogen, into the body to generate an immune response, mRNA vaccines do not require viral material at all. Rather, based on information gleaned from sequencing viral genetic material, these vaccines use strands of mRNA to provide the human body with genetic instructions to produce a viral antigen, such as a protein. 

Once injected, the mRNA enters cells, which manufacture the antigen and give the immune system the exposure it needs to build immunity, without actually causing an infection or exposing people to any form of the virus.

Compared to the conventional approach to vaccine development, mRNA vaccines can require less time to advance. Currently, it takes about a week to produce an experimental batch of mRNA vaccine, compared to the months required by traditional vaccine manufacturing processes that rely on chicken eggs or mammalian cells. Scientists also anticipate that the production process can be rapidly scaled and standardized to accelerate distribution. 

On December 11, 2020, the U.S. Food and Drug Administration (FDA) issued an Emergency Use Authorization (EUA) for the first vaccine for the prevention of the novel coronavirus that causes COVID-19. This vaccine represents the first successful vaccine that was developed using mRNA technology, as well as a historic milestone in vaccine science, given the unprecedented R&D timeline.

Subsequently on August 23, 2021, U.S. regulators approved Pfizer and BioNTech’s COVID-19 vaccine for patients 16 years and older based on extensive review of clinical, manufacturing and other key data. It is the first vaccine for the prevention of COVID-19 to receive approval from the FDA. The FDA’s approval of Pfizer-BioNTech’s mRNA vaccine marks a significant step forward in our work to end COVID-19. According to the FDA, “the vaccine also continues to be available under emergency use authorization (EUA), including for individuals 12 through 15 years of age and for the administration of a third dose in certain immunocompromised individuals.”

In announcing the news, Acting FDA Commissioner Janet Woodcock, M.D. noted, “While this and other vaccines have met the FDA’s rigorous, scientific standards for emergency use authorization, as the first FDA-approved COVID-19 vaccine, the public can be very confident that this vaccine meets the high standards for safety, effectiveness, and manufacturing quality the FDA requires of an approved product.”

To date, a second mRNA vaccine for the novel coronavirus received an EUA as well.

Ensuring Safety And Effectiveness

Because mRNA vaccines do not use an inactivated virus, but rather a portion of the viral sequence encoding for one or more viral antigens, no virus is needed to make a batch of mRNA vaccine. Additionally, mRNA vaccines have demonstrated a favorable safety profile in research studies.

Still, the human body is incredibly complex, and scientists rely on clinical testing to ensure a vaccine's safety and effectiveness. That’s where Dr. Badkar and his team come in. As the head of Pfizer’s Novel Delivery Technologies (NDT) group, he helps guide the formulation and process development of vaccines through clinical trials to commercial readiness. This includes the need to scale up manufacturing to produce large quantities of any potential vaccine.

Dr. Badkar also helps ensure adherence to strict quality and regulatory standards designed to protect patient safety and assure consistent product quality. Across the board, vaccines undergo extensive testing for safety and effectiveness prior to any regulatory approval. Once a vaccine is licensed, regulatory authorities and the vaccine sponsor routinely monitor its use and investigate any potential safety concerns.

Responding To A Global Need

As the world continues to feel the impact of COVID-19, the biopharmaceutical industry continues to work around the clock to identify and develop safe and effective vaccines to prevent infection, while also researching and developing new ways to treat those infected with the virus.