A Vaccine

Today a 90 year old lady in Coventry, England, became the first person in the UK to get a production version of the BioNTech/Pfizer vaccine. Meanwhile, earlier this week, a Wyoming state health official, Igor Shepherd, who works on the state’s covid response, said that the “so-called pandemic” and efforts to develop a vaccine are plots by Russia and China to spread communism worldwide. He is apparently not alone by a long shot.

Here’s my two cent understanding of how an mRNA vaccine works (Michelle – could you please run it by Alu and see if it is somewhat correct).

photo by Getty Images

The corona virus consists of a genome of RNA enclosed in a protein envelope with spike proteins on its surface, giving it that special sucker-ball look. These spike proteins are what allows a virus to stick to a corresponding receptor protein on a human cell surface, and then poke through the cell wall and transfer its genome to the host cell. Once inside the host cell, the genomic RNA replicates itself and it hijacks cellular organelles called ribosomes within the infected host cell to make viral proteins including new copies of the spike protein. It can do both because it is a strand of RNA which is both a genome and a messenger RNA. The proteins and the replicated RNA self assemble into new virus which infect more cells in our bodies. But it isn’t all one-sided. Our adaptive immune system marks the spike protein that is causing all the fuss as an antigen. In a series of amazing molecular orchestrations via different immune cells, our body produces yet another very specific matching protein called an antibody. The antibody can latch on to the antigen like one puzzle piece fits into another. If all the spike proteins in the invading virus are locked by antibodies in this way, the virus can’t use its spike proteins to invade cells. Additionally, the antibodies, once latched to antigens, mark those virus for destruction by other immune cells. This is how the body fights the virus. The adaptive immune system has a memory. If your body encounters the antigen in the future, it quickly recognizes the antigen and produce lots of antibodies to bring to the battle, thereby preventing future infections. Incidentally, antigen tests for covid work by looking for the corona virus antigens in your tissue sample instead of the virus genetic material itself. Because it is easier to test for a protein, these tests are faster, but they are also less accurate – you may be infected but you may not yet have sufficient antigens to produce a positive covid test.

Back to the vaccine. So the BioNTech and Pfizer scientists first synthesized the mRNA strand that encodes for the corona virus spike protein. This is a portion of the corona virus genome but it isn’t grown from the virus. Instead it is built from scratch. The mRNA strand is then wrapped in a tiny oily bubble made of lipid nanoparticles. When sufficient number of these are injected into your arm, some of these bubble wrapped mRNA packages bump up against your cells and fuse with them and release the mRNA into that cell. Once inside the cell the mRNA does what mRNA do – it instructs the cell’s ribosomes to make the protein encoded in its structure – which happens to be the corona virus spike protein. And once your vaccinated host cell produces the spike protein in sufficient quantities, your body’s immune system takes over and produces antibodies just as if you have a covid infection. Because this bit of mRNA knowns only how to make the spike protein, it does not know how to replicate itself or make the other proteins needed to assemble a virus. So you can’t get infected. But bam, you are protected against infection.

These vaccines are feats of modern science. They wouldn’t be here without the rigor and expertise that the anti-science crowd berates. Government organizations like the NIH, the CDC, and the FDA in the US and corresponding organizations in other countries, and private research and pharmaceutical companies from around the world, and billions of taxpayer dollars have funded the research and the build-up of the manufacturing capacity for this vaccine. Thousands of scientists have worked through the pandemic to get here. There are still unknowns. This is the first time that a vaccine using mRNA has been approved for human use. Are there long term side effects or problems? Can we afford to wait to find out?

The covid vaccine may be the defining scientific moment of my time. Unless it turns us all into controllable communists. Is the vaccine right for you? Here’s a simple test: if you agree that Trump won this election, don’t get the vaccine. Instead, gather in large numbers indoors without masks. If you are concerned about state or local laws the limit how many people can meet, don’t worry. Go meet at church and you’ll be fine. Really. The Supreme Court said so.

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