Many people wonder if current seasonal influenza vaccines, commonly known as flu shots, contain messenger RNA (mRNA) technology. The vast majority of currently available seasonal flu shots do not use mRNA technology. This question often arises due to the widespread use of mRNA-based COVID-19 vaccines in recent years. While mRNA technology represents a significant advancement, traditional flu vaccines protect against influenza viruses through different, well-established mechanisms.
How Traditional Flu Shots Work
Traditional flu shots function by introducing components of the influenza virus to the immune system, prompting it to build protection without causing illness. Most flu vaccines contain inactivated (killed) virus particles, meaning the virus cannot replicate or cause disease. Some vaccines may use weakened live viruses, known as attenuated viruses, or specific proteins from the virus, such as hemagglutinin, which are key to the virus’s ability to infect cells.
These vaccine components are recognized by the body’s immune system as foreign. In response, the immune system produces specialized proteins called antibodies, along with other immune cells, to neutralize the viral components. This process trains the body to quickly recognize and fight off the actual influenza virus if exposed in the future. It generally takes about two weeks after vaccination for these protective antibodies to develop.
The manufacturing of traditional flu vaccines relies on three different technologies. The most common method, used for over 70 years, is egg-based production, where selected flu virus strains are grown in fertilized chicken eggs. Another method involves cell-based technology, where flu viruses are grown in cultured mammalian cells instead of eggs. A third approach, recombinant technology, does not use eggs or live virus. Instead, it isolates a specific protein, like hemagglutinin, from the flu virus and combines it with another virus that grows well in insect cells, which then produce the flu protein for the vaccine.
Understanding mRNA Vaccines
Messenger RNA (mRNA) vaccines represent a distinct approach to stimulating an immune response compared to traditional vaccines. Instead of introducing viral components directly, mRNA vaccines deliver genetic instructions to the body’s cells. This mRNA guides the cells to produce a particular viral protein, such as the spike protein found on the surface of the SARS-CoV-2 virus.
Once these viral proteins are produced, the immune system recognizes them as foreign. This triggers an immune response, leading to the creation of antibodies and specialized immune cells designed to target and eliminate the threat. Importantly, the mRNA from the vaccine does not enter the cell’s nucleus, where human DNA is stored, meaning it cannot alter a person’s genetic material.
The mRNA instructions are temporary and are quickly broken down by the body’s cellular machinery once protein production is complete. This ensures the genetic material does not persist in the body. mRNA vaccines teach the immune system how to respond if it encounters the actual virus in the future, preparing the body for a more effective defense.
Current Flu Shots and mRNA Technology
Current seasonal flu shots do not contain mRNA technology. They are produced using established methods, relying on inactivated viruses, weakened viruses, or specific viral proteins to elicit an immune response. The technology behind the currently available flu shot is distinct from the mRNA platforms used for some other vaccines.
While traditional flu vaccines remain the standard, significant research and development efforts are underway to explore mRNA-based flu vaccines. Pharmaceutical companies, including Moderna and Pfizer, are actively conducting clinical trials for mRNA flu vaccine candidates, with some already showing promising results in late-stage studies. These experimental mRNA flu vaccines aim to offer potential advantages, such as faster manufacturing times and the ability to more precisely match circulating flu strains.
Despite ongoing research and positive trial results, mRNA flu vaccines are not yet licensed or widely available to the public. The flu shots offered each season utilize conventional vaccine technologies, ensuring continued protection against influenza based on decades of scientific understanding and production experience. The development of mRNA flu vaccines represents a future possibility rather than a current reality for seasonal influenza prevention.