I hope you all were able to nerd out on yesterdays message because today’s may be a bit worse but it is getting us to the science we all need to understand regarding a Covid-19 vaccine.
We discussed how presenting the human immune system with the three dimensional structure of a pathogen allows us to build a very specific 3D antibody that we can use to ‘lock up’ the infectious agent. Now lets consider how we could present the immune system with something like this that doesn’t cause the actual disease or trigger any adverse immune consequences. Historically we have developed vaccines mostly through these platforms; Inactivated Vaccines- The infectious particle is killed but left in-tact and injected into the host (human). Influenza, Hepatitis A, Rabies, and Polio are examples.
Live Attenuated Strain Vaccines- This strategy allows us to use a weakened form of the virus that has some of its virulence removed by removing genes or selecting out the weakest version of a virus found in nature. Measels, Mumps, and Rubella (MMR) are examples.
Subunit Vaccines- This takes elements of the outer coat (antigen) of a bacteria or virus, attaches them to a protein carrier, and then injected into a host (human) that produces antibodies against the antigen. Pneumonia, H-Flu and Meningitis are examples.
Toxoid Vaccines- These vaccines are developed using a toxic product that an organism may make that can hurt us. We use the structure of the toxin (made non toxic) and inject into a host (human) to produce antibodies against. Diptheria and Tetnus are examples.
These vaccines have generally worked well with occasional complications usually related to immune system over response creating inflammatory states. I don’t know of any vaccine of this type that has taken less than ten years to develop. The Ebola Vaccine came out relatively quickly following the outbreak in Africa in 2013-16. What most people don’t know is that it had been in the works for many years. Here is a link to a great story; https://www.statnews.com/2020/01/07/inside-story-scientists-produced-world-first-ebola-vaccine/
These traditional models of vaccine development are not likely to produce a meaningful product in a short period of time. This is in part because the science is complex but also in part because determining their safely and efficacy are long arduous processes. After the science is done and we’ve cooked up the vaccine we then move to animal studies, then human studies, and then wait to see long term results. We need to know how long does the immunity last and what other side effects have we triggered. Does the effectiveness of the vaccine outweigh the risk etc… You can see why vaccines are years in the making. I am concerned that many of these crucial safety steps will need to be curtailed or bypassed completely to get anything to market in a timely fashion.
Lets look at Moderna’s promising mRNA vaccine. This is a whole new vaccine development platform never used in a large scale on humans before. Moderna had been using this technology to develop a Cytomegalovirus (CMV) vaccine which is in human testing but un-deployed on a large scale. This technology actually inserts RNA (a gene) from the Corona virus into human cells. The human cell then produces the protein product this gene codes for in this case Covid’s Spike Protein. These particles are released into circulation, the immune system see them, and develops an antibody against them.
Pretty clever but I have significant reservations about inserting any viral genes into any human. I think it would take decades to understand the full repercussions of this technology.
So this is a really long lead in to me giving my humble opinion that we need an effective treatment for Covid rather than a vaccine rushed to market. With an effective treatment we can decrease morbidity and mortality while society goes on to develop herd immunity like we’ve done with the other four common Corona viruses that circulate. I’ll go into depth on current treatment status soon.
Thank you for indulging me. I would value people’s opinion on this current missive. Is this way too much info? is it presented in a format that is difficult to understand? Are you tired of my ramblings? Please let me know and if you need me to shed more light on any other topics that would help to ease your stress/distress on Covid do not hesitate to reach out.