How Does a COVID mRNA vaccine really work?

Abstract

The most potent weapon against COVID-19 is a vaccine based on messenger RNA (mRNA). The first of these vaccines authorized for use was developed by the German company BioNTech in cooperation with Pfizer, closely followed by the (U.S.-produced) Moderna vaccine. These vaccines send a piece of mRNA into cells of a host. The mRNA instructs the cells to produce masses of the same spike protein that also occurs on the shell of the real coronavirus. The immune system responds by learning to destroy anything showing that protein: if the real virus arrives, the immune system will attack it immediately. This much has been reported widely by the media. But important questions remain. How is mRNA actually synthesized as a transcription of the spike-producing segment of the virus' RNA? How is the selection and replication done? How does mRNA enter a host cell, and how long will it stay there? Will it produce the spike protein forever? Is it perhaps dangerous? And the biggest question of all: How does the immune system record the structure of the foreign protein, how does it recognize the invader, and how is the immune response cranked up? To answer these questions, we bring you a conversation between Ubiquity editor Walter Tichy and his daughter Dr. Evelyn Tichy, an infectious disease expert.