Artem Podrez/PexelsThe COVID-19 pandemic has brought unusual attention to everything from handwashing to polymerase chain reaction tests. As we move into the later stages of this pandemic, though, a different scientific concept has dominated the national conversation: vaccines. The study of the human immune system and how vaccines influence it is complex and sometimes counterintuitive, and the deployment of a new method for immunization based on mRNA has made it all the more confusing.
Still, if the end goal of each type of vaccine is the same, why does it matter which one is used? The answer comes down to the characteristics of the target pathogen, as well as the timeframe under which the vaccine is being developed. The advantage mRNA vaccines have isn’t necessarily that they’re better at inducing immunity, says Bernard Verrier, the director of the Laboratory of Tissue Biology and Therapeutic Engineering at CNRS-Université de Lyon, it’s that they’re fast. Not only is the initial production of an mRNA vaccine rapid, the manufacturing is reactive, meaning it would be quick and simple to substitute in a different mRNA sequence if the target pathogen mutated.
Other vaccines, for example protein subunit types, make use of an adjuvant, which is a substance that jumpstarts the immune system. mRNA vaccines don’t need adjuvants because the mRNA sequences themselves, along with impurities in the form of double stranded RNA, trigger the immune system.
Ummmm, they don't.