Riding high on Covid-19 vaccine success, FDA boosts mRNA vaccine reviews

The success of Covid-19 messenger RNA (mRNA) vaccines has highlighted the promising advantages of this technology in immunisation, prompting the United States Food and Drug Administration (FDA) to increase the number of review designations for mRNA vaccines in recent years.

Review designations by regulatory agencies such as the FDA represent significant steps in evaluating and potentially approving new drugs or vaccines. They involve a comprehensive assessment of safety, efficacy, and quality data provided by pharmaceutical companies during clinical trials.

In 2023, a record nine review designations were awarded to mRNA vaccines for eight different conditions, reflecting the FDA’s commitment to fostering broader applications of these vaccines, according to GlobalData, a data and analytics firm.

mRNA vaccines distinguish themselves by utilising synthetic messenger RNA to instruct cells in the body to produce proteins that trigger an immune response. Unlike traditional vaccines that use weakened forms of viruses or bacteria, mRNA vaccines employ synthetic messenger RNA to encode parts of the virus, prompting the immune system to recognise and combat the disease.

The success of Pfizer-BioNTech and Moderna’s Covid-19 vaccines highlighted the potential of mRNA technology. Starting with the FDA approval of Pfizer’s Comirnaty in August 2021, followed by Moderna’s Spikevax in January 2022, these vaccines marked a significant breakthrough by preventing an estimated 14.4 million deaths from Covid-19 globally, as per paper published in The Lancet in 2022.

 “Since the first FDA review designation for an mRNA vaccine in 2018, 25 designations have been awarded. Notably, 2023 saw an 80% increase in review designations over 2021, extending to varied indications including human metapneumovirus and metastatic melanoma,” Jasper Morley, a pharma analyst at GlobalData, said.

“mRNA vaccines’ success against Covid-19 has prompted an increased number of FDA review designations, suggesting a regulator-driven boost in developing mRNA vaccines for diverse ailments,” Morley said.

This surge indicates the FDA’s intent to promote mRNA vaccines for conditions beyond Covid-19, a notion crystallised by the approval of Moderna’s mRNA vaccine for respiratory syncytial virus (RSV) in May 2024. Moderna’s mRNA-1083, which received four fast-track designations in Phase III trials for Influenza A, Influenza B, and Covid-19, is anticipated to hit the market by 2025, further expanding the horizon for mRNA applications.

“mRNA technology is the way to go. The ongoing work allowed us to develop a vaccine during the pandemic with good efficacy. This advantage positions mRNA to potentially replace other technologies, such as vector-based vaccines. It's a cost-effective step forward that enables rapid development of new products,” Vaccinology expert Naveen Thacker, a member of the Covid-19 expert task force of doctors formed by the government and President of the International Pediatric Association added.

The World Health Organization’s (WHO) Science Council supported these sentiments in a report published in December 2023, emphasising the need for robust research and development to overcome mRNA technology's limitations, such as temperature sensitivity and cost barriers in low-income countries.

Professor Harold Varmus, Chair of the WHO Science Council, had said that to maximise mRNA’s potential beyond Covid-19, research must aim to develop more stable and broadly effective vaccines.