We are coming up against a time when a vaccine against Covid-19, also called SARS-CoV-2, may become available.
Viruses mutate very rapidly, changing their surface proteins and such. The virus variants that are best at evading the human immune system are the ones that prosper, which makes our challenges in fighting them very difficult. Yet, effective vaccines againsts the Covid-19 virus are now being developed. It may be that, like influenza vaccines, new Covid-19 vaccines will need to be administered each year, in order to keep up our collective immunity.
There's one thing I am certain of regarding a Covid-19 vaccine in modern America, however, and that is that in all respects, it will be a politically and culturally charged issue.
Thus, I wish to explain the four types of anti-viral vaccines, so that you are all prepared for the time when we will face the personal and societal decision on being inoculated.
Similar-Species Vaccines are not common today, but were very important historically. The world-changing smallpox vaccine used cowpox, a poxvirus that was similar enough to smallpox to protect us against it, but not cause disease in humans. The Covid-19 vaccines currently being developed are not of this type.
The next category is Live-Attenuated (weakened) Vaccines. Attenuated vaccines can be made in several different ways, but they all involve passing a virus through a non-human host in the lab. Sometimes, for up to 200 cycles. The goal is to produce a version of the virus that can still be recognized by the human immune system, but cannot replicate (make copies of itself) well inside our bodies. Examples of attenuated vaccines include MMR (Measles, Mumps, Rubella), Chickenpox, Influenza, and Rotavirus.
There is one concern with attenuated viruses: that they may, through random mutations, regain the ability to replicate within the human body and cause illness again. The most significant example of this in the U.S. was the oral polio vaccine, which was an attenuated virus. In extremely rare cases, it mutated fast enough to cause polio again, so we switched the polio vaccine to the next category of vaccine types in order to 100% avoid this complication.
The next category is Inactivated Vaccines, which are produced by "killing" the pathogen with chemicals, heat and/or radiation.
(Sometimes, to be as certain as possible of total kill, researchers even expose the virus in question to repeated recordings of the rants of modern American Members of Congress and other politicians ...)
Note, I placed the word "killing" in quotations marks above. This is because a virus, in a philosophical sense, isn't really alive at all, at least in some ways of looking at it. Viruses are inert outside of their host, and don't really "do" anything at all until they make their way in and start causing trouble. It's a very weird concept to grapple with.
Any event. I imagine the technical trick with making inactivated vaccines is to wreck the virus DNA or RNA, so that it can't do anything to harm us, and yet leave the outer protein coat relatively intact. In this way, our immune system can still recognize the protein shapes it has to in order to fight the virus. It's a clever balance!
The fourth category of vaccines against viruses is the newest one, in use since the 1980s, and it's really clever: Subunit Vaccines.
What if we could take just parts of the protein shell, that our immune system can recognize, and not have any viral DNA or RNA at all? Without its DNA or RNA, a virus isn't a virus. Its genetic code is what enables it to harm us by telling the cells it enters to do something that the virus "wants" instead of going about their normal business. Robbed of its genetic material, such a mere shell of a virus makes the iconic country singer who's lost his gal, tore his best jeans and crashed his pickup truck look like the luckiest guy in the world.
To make a subunit vaccine, just one viral gene coding for one vaccine protein is inserted into producer cells in culture; often, yeast. The yeast (bless the little beasties, who also make us bread and beer) pump out this one protein, a vaccine is made with it, and even though our immune system doesn't get to "see" the whole virus, often times, one piece of it is enough to stimulate an effective immune reaction. Those red spikes on Covid-19 look like mighty fine targets, don't they?
The Hepatitis B and HPV (human papillomavirus) vaccines are examples of subunit vaccines.
What does this all mean for us as we go forward? The Covid-19 vaccines that reach commercial development are not going to be similar-species vaccines, so we can forgo that category.
For me, if a Covid-19 vaccine is a subunit vaccine or an inactivated vaccine, I have no worries at all about receiving it. Sign me up to go first, give me twenty boosters, I'm not worried about a thing.
If the vaccine is an attenuated one, I'll still get it, but even as a health care worker, I'm inclined to hold back for just a little while, to ensure that no Covid-19 infections result from it. Especially considering that this whole enterprise is a rush job. Probably just a month or so would be enough to make the call.
In my view, though, the rigid anti-vaxxer stance is foolish, misinformed and just a staggering example of human confirmation bias, in which no amount of real-world facts can change emotionally charged beliefs.
We get to have our own opinions, yes. But we don't get to have our own facts.
I sincerely hope that this post helps you all understand anti-viral vaccines better than you did before, and gives you the confidence to receive them, should Covid-19 vaccines become available.
Oh, and this year of all years, please get your flu vaccines.
And floss.
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