The Potential and Future of the mRNA SARS-Cov-2 Vaccines
By: Carolyn Mish, Contributing Writer
Since the early months of the COVID-19 pandemic, biotechnical companies worldwide have been scrambling to create an effective vaccine for the novel coronavirus. While effective treatments such as Remdesvir have been approved for emergency use by the Food and Drug Administration, creating a successful vaccine was shortlisted, though vaccine creation is one of the longest timelines in medicine.
Within normal conditions, vaccines can take up to a decade to be deemed safe for the public. This is largely due to the bureaucratic processes that take time when other vaccines and medicines take up government time and resources. The FDA usually takes 6 months to approve a tested vaccine for widespread use. There are six main stages to creating a vaccine; exploratory, pre-clinical, clinical development, regulatory review and approval, manufacturing, and quality control.
Clinical development is a three step process in itself. During phase 1, the first group of adults to receive the vaccine are administered it to gauge immune response and the overall safety of the vaccine. Phase 2A involves expanding the control group to determine an effective dosage. Then comes Phase 3. During the third phase, more volunteers receive the vaccine to determine its effectiveness. This step usually takes the longest; to gather a large volunteer pool and confidently determine the effectiveness of the vaccine takes time. However, due to the global need for a SARS-Cov-2 vaccine, companies such as Pfizer and Moderna were able to amass the necessary volunteer groups within months. During Phase 3 of testing a SARS-Cov-2 vaccine, volunteers would first test negative for the virus, then half of the group would be given the true vaccine and half would receive a placebo. This allows scientists to determine the effectiveness of the vaccine. The next step is regulatory review and approval. Companies submit an application for approval to the FDA and wait. The FDA can choose to approve (or license) the vaccine.
Due to the urgency of this vaccine, the process has been globally expedited. This includes the use of a EUA; an Emergency Use Authorization. This allows unapproved medical solutions to be used in the event that there is no adequate alternative available. EUAs have been used in the past to help treat the Zika Virus, as well as Ebola. This doesn’t signal a lack of review; instead, a reallocation of resources to speed up the process while ensuring that the result is safe and effective to those who receive a potential vaccine.
That being said, two main companies have emerged from clinical trials with promising findings. Pfizer, and their German partner BioNTECH, announced on Nov. 18 that their mRNA based vaccine was 95% effective, and that their third phase of testing had met their efficacy goals. The way a mRNA vaccine works is by injecting the genetic material of the virus and allowing the cells of the injection site replicate the mRNA. This process mimics what COVID does when a person is infected, but on a much smaller scale that does not include disease; this preview allows the body to build immunity. Moderna announced on Nov. 16 that their mRNA vaccine had reached 94.5% effectiveness during preliminary analysis of their third phase of testing. Both companies will submit EUA applications and if successful, plan to distribute up to a billion doses by the end of 2021.
Now that promising vaccines exist, who will receive them? Due to the increased risk the elderly face, they are top priority to receive a vaccine, alongside healthcare workers and other essential workers. The numbers in vaccine allocations are difficult; Pfizer projects that they could administer 13.5 million vaccines by the end of 2020. There are an estimated 17 to 20 million healthcare workers living in the U.S. Despite the ethical issues around vaccine distribution, agreements have been made between companies and the government to make the vaccine accessible.
Two aspects of the vaccines make them difficult to distribute. The Pfizer-BioNTech vaccine needs to be stored at -70℃, which is colder than most pharmacy and hospital freezers. The Moderna vaccine needs to be stored at 20℃, which is more manageable. Both vaccines need to be preserved in these conditions due to their mRNA composition; enzymes easily break down in the wrong conditions, despite structural efforts to preserve the genetic material. With both vaccines, these conditions add significant costs and effort when distributing the vaccine to the masses.
Both vaccine companies plan to apply for regulatory review in countries globally. Even after a vaccine is approved and distributed, the FDA will monitor its recipients to ensure adverse effects are not an issue. The potential creation of an effective, accessible vaccine in record time is an exciting advancement not just for pharmaceutical companies, but for humanity at large.