Understanding COVID-19: How mRNA Vaccines Work

Messenger RNAs, mRNAS, are the messages that the cell uses to create a variety of proteins, which are building blocks and tools for cell function and survival. mRNA vaccines send that message with a blueprint, and it's a message that has an auto destruct feature, like Mission Impossible or a Snapchat message. The mRNA vaccine takes the blueprint of the viral spike protein, and enables the immune system to generate very protective high level neutralizing antibodies. The body recognizes that spike protein and remembers that it has seen it before, so that next time when there is an infection, it attacks the full virus.

Reports from the phase three trial of these vaccines show remarkable efficacy, even in different ethnic groups and age groups, which is quite significant because older adults tend to have lower responses to vaccines. The vaccines also have an efficacy of 95% of preventing symptomatic COVID disease. And this is very encouraging because this will allow rapid and thorough control of viral infection in the population.

The study also found that after a single dose of vaccine, some individuals did not approach the target antibody range. The boost from the second dose was needed to provide maximum protection. Additionally, having that booster dose will impact the durability or the longevity of the immune response generated.

In the past 10 to 15 years in the field of vaccinology and public health preparedness, there's been this focus on technologies in which we as a country and the world invested, without knowing what they would be targeting. mRNA vaccines have been tested in multiple clinical trials before, for infections like the Zika virus, HIV, and influenza. The mRNA vaccines are taking a small piece of the viral sequence and making mRNA out of them. It's not the entire virus, as it's impossible to make a whole virus out of the mRNA. The attractiveness of this technology is that you can program that message into an mRNA relatively quickly and with the vaccines being sorely needed it can be scaled up to meet that demand.