Health Secretary Robert F. Kennedy Jr. has raised concerns about the safety of mRNA vaccines for Covid-19. Scientists have sought funding from the National Institutes of Health: Scrub their grants of mRNA references. State legislatures nationwide are debating bills that aim to ban or limit these vaccines. Weapons of mass destruction.
Messenger RNAs (mRNAs) have gained significant attention recently, though they were first discovered in 1961. Since then, scientists have explored their potential in preventing infections and treating cancer and rare diseases.
What is mRNA?
mRNA is a large molecule present in all cells, serving as a template to produce the proteins encoded by our DNA. It carries instructions from the DNA in the nucleus to the cell’s protein synthesis machinery. According to Jeff Koller, a professor of RNA biology and therapy at Johns Hopkins University, a single mRNA molecule can generate multiple copies of a protein, and is designed to break down after fulfilling its role.
How do mRNA vaccines work?
Currently, there are three FDA-approved mRNA vaccines for older adults. These vaccines utilize strands of mRNA that encode specific viral proteins.
Upon receiving a Covid-19 vaccine, the mRNA chains, encapsulated in tiny fat particles, enter muscle and immune cells, explained Robert Alexander Wesselhoif, director of the RNA Therapy Institute at Mass General Brigham’s Institute of Genetic and Cell Therapy. These intracellular factories then use mRNA instructions to produce proteins resembling those on the Covid-19 virus surface. The body perceives these proteins as foreign, triggering an immune response.
While most mRNA degrades within days, the body keeps a “memory” in the form of antibodies, noted Dr. Koller. As with other vaccines, immunity may wane over time, requiring updates for new variants.
Why are mRNA vaccines being used now?
In the mid-2000s, researchers at the University of Pennsylvania discovered a method to introduce foreign mRNA into human cells without it degrading first, paving the way for vaccine development.
Currently, the primary application of these vaccines is to prevent infectious diseases like Covid-19 and RSV, according to Dr. Wesselhoeft, who founded a company focused on RNA therapy. mRNA vaccines can be developed quickly, as the non-RNA components remain consistent across different vaccines.
This rapid development could aid in creating annual flu vaccines, stated Florian Krammer, a virologist from the Icahn School of Medicine at Mount Sinai. Typically, choice of flu vaccine strains is made in late winter, but mRNA vaccines can adapt more swiftly, allowing for better efficacy against circulating strains.
Are these vaccines safe?
A common question is whether mRNA vaccines can impact DNA. Dr. Boucher clarified that this is not possible; mRNA cannot be converted into DNA or integrated into the genome.
Covid-19 vaccines may cause temporary muscle pain and other mild side effects, as noted by Dr. Krammer.
Dr. Adam Ratner, a pediatric infection specialist in New York, remarked that in the over four years since the rollout of the Covid-19 vaccine, there have been “no long-term safety signals.” He noted parental concerns regarding myocarditis, an inflammation of the heart, but emphasized that the risks associated with actual Covid-19 infections far outweigh those of vaccination.
What additional applications does mRNA have?
mRNA-based vaccines may target a variety of diseases, including cancer, cardiovascular conditions, autoimmune disorders like type 1 diabetes, and rare diseases such as cystic fibrosis.
For cancer, the concept is that mRNA can encode tumor-associated proteins, prompting an immune response against tumors. In genetic disorders like cystic fibrosis, mRNA can produce a functional version of a missing protein, restoring normal function in affected tissues.
A recent paper published in Nature outlined an experimental mRNA vaccine for pancreatic cancer, which elicited immune responses in some patients post-surgery. Those who experienced immune activation had improved survival rates compared to those who did not.
Another study on monkeys investigated inhaled mRNA therapy aimed at producing proteins necessary for cilia formation, which play a crucial role in clearing mucus in the airways. This therapy targets dysfunctions associated with primary ciliary dyskinesia.
This research is in its preliminary stages, with the Phase I trial for pancreatic cancer involving only 16 patients, which may lead to variability in survival outcomes. Dr. Stephen Rosenberg, an expert in cancer immunotherapy at the National Cancer Institute, has indicated that interventions can stimulate immune responses without significantly altering patient outcomes.
Dr. Richard Boucher, a pulmonary scientist at the University of North Carolina at Chapel Hill, noted that targeting the correct cells with mRNA-carrying particles for lung diseases is particularly challenging.
Overall, Dr. Ratner described mRNA vaccines as “exciting” and holding promise for treating conditions where prior technologies have struggled. However, he cautioned that mRNA therapies should be seen as one of many drug technologies, with varying efficacy depending on the illness.
Source: www.nytimes.com
