Thursday, March 25, 2021

COVID-19 Immunity and Vaccination: An Update From the Front

I've been away from the blog for a while, as it's been a very busy semester! But things have calmed down and I'm back.  

"Should I get the vaccine?"

This is the question of the moment in my practice. To some this may seem odd. Who wouldn't want it? People are "jumping the line" and engaging in all sorts of cheats to get their shots. I heard a woman interviewed on NPR recently who said she wept when she got hers, she was so relieved to have been vaccinated.

So who wouldn't want this? 

Today we're talking about "vaccine hesitancy" which is, I believe, a kinder and more accurate term than "anti-vaxxer", which has also gained popularity as description of online communities and public antagonists who ardently oppose artificial immunization. The latter are a diffuse and widespread group who believe that vaccines are bad for health, and some who argue that vaccine programs are a plot against ordinary folks, a plot by drug companies to get money, a plot by governments to sicken or control people. 

I've stated elsewhere in this blog that artificial immunization generally works as it is supposed to, that in a sense it mimics homeopathy in its approach to disease reduction, that its value is often overstated by its promoters and understated by its opponents, that it has had less effect on population health than improved sanitation and nutrition have, and that in some it can lead to enduring negative health effects, but that predicting who will suffer such effects is difficult. As I have noted elsewhere, it can confuse early homeopathic treatment, but most people seem to do ok. In the end, it is a risk-to-benefit analysis that must be calculated by the person considering immunization. 

"Ok, ok...but should I get the vaccine?"

There are two things to consider here. The first is protection from future disease, and the second is the social climate around this disease. The first feature is the easier to navigate, so let's address that now.

There's been a lot of mixed messaging around immunity from SARS-CoV-2--the "coronavirus". Of course there are many coronaviruses, and some cause the common cold, so it's likely many of you have had a "coronavirus" before. Some are more serious, and it's true that novel viruses, like SARS-CoV-2, and its cousins SARS-CoV-1 and MERS-CoV, often caused more severe disease in people because they are new. We come into this world with a set of instructions for beating most of the common germs, and even instructions for some things not so common. But these instructions vary in their detail. Once exposed to some germ or another, those instructions for generating an immune response to that germ are revised, refined. Next time we come into contact with it, we're likely to respond better and faster, and may not even get symptoms at all.

This is one reason COVID-19 has been more lethal than the flu or common cold: we didn't have the best set of instructions for developing an immune response. Nevertheless, many people who "got" COVID didn't get too sick, or they got pretty sick but got better without having to be hospitalized. A lot of people git very sick, and many died, and sometimes this was because of immune senescence (older folks' immune systems decline in effectiveness), general poor health (obesity, diabetes, heart disease, etc.), and--sometimes--bad luck. It would be silly to ignore the fact that some otherwise perfectly healthy people in good shape got "the 'rona" and just died. Some day we may discover some genetic or other peculiarity that explains this, but right now, we just have to accept that there is vulnerability across the lifespan, even if that vulnerability varies somewhat.

I must add that some germs are just more deadly for reasons other than or in addition to their novelty in people. So of them are just bad--keep that in mind as well. COVID-19 seems to be staying at around 1-2% mortality, so it's still more deadly than a cold or the flu. 

Given the facts of the case, lacking immunity to this coronavirus--whether naturally acquired (had the disease) or artificially acquired (immunized)--poses at least some risk. The vaccine rollout addresses this pretty well. Frontline health workers and older people are first in line. Viewed another way: people constantly exposed to sick people, and the folks most likely to die from COVID need to be considered most at risk and they get the shots first. There are controversies about prioritization..., but let's not get into that here. You get the basic concept.

"I had COVID. Do I still need the vaccine?"

The short answer from my perspective is: we don't know. Currently, public health authorities recommend it if you're in an eligible group. They say this is because we don't know how long natural immunity lasts. Some experts suggest natural immunity isn't as durable as artificial immunity, but the science is murky, and some experts argue that natural immunity comes with significant risks, but if you already had COVID and survived without any subsequent health problems, that safety concern is moot, and it's likely immunity will persist for a time. It's possible that natural or artificial immunity will be similarly durable, and right now we don't know what that durability is...three months? A year? Two years? 

And as the virus evolves new versions of itself, will we have protection from those? Early research suggests, yes, probably. Again, for how long? We're not sure. So for now the message from most experts is: "When your turn in line comes up, get it!" regardless of whether or not you already had COVID.

I've been reading research reports and right now there's evidence that we don't maintain antibodies for longer than three months after infection. Antibodies are chemicals our immune cells make to bind to germs and deactivate them promptly, but you have to have been exposed to the germ at least once, first. "Circulating antibodies" have been considered a medical measure of immunity to infectious diseases. For example, my students sometimes have to get them checked for things like measles or mumps, to see if they need a booster shot before entering nursing school. 

With this pandemic, there's been intense interest in memory cells. When we get an infection, B- and T-lymphocytes--types of white blood cells--"learn" the nature of the novel germ. They use this pattern recognition to develop effective, targeted responses to beat the infection. They also generate a few copies of cells that don't join the fight. Those cells just go hide out somewhere until it's over. These are memory cells. They remember the pattern so that the next time that germ shows up, they can quickly generate new antibodies and new killer cells to mop up the problem fast, sometimes without even any symptoms! 

We've known about this process for decades, but this level of interest in it is new, and happening because of the pandemic, so you can't go to Quest or LabCorp and get your memory cells tested! It's all just research at this point.

But we now know something important that we didn't really think about before: that circulating antibodies are not the only measure of immune defense. Indeed, we now have some research that suggests this response, what immunologists call the "anamnestic response", may be more important to COVID immunity than how much antibody is swimming around in your blood. The latest research suggests this may be at least 8-12 months. I include links here for the science nerds, Rodda, et al. 2021, Quast & Tarlinton 2021. This isn't comprehensive, but gives an idea.

"And soooo?"

Right now, I'm telling people that if they had COVID within the last year or so (the period of time we have at least some evidence for), and if they want to wait a while, it's probably ok to do so. Why wait? One doesn't have to, but some people are, rightfully in my view, a little cautious about a brand new drug and a brand new technology (mRNA vaccines) until a little more time goes by. That's their personal risk-to-benefit analysis.

I'm also inclined to have people get immunized if they have special vulnerabilities (age, disease) and they have not already had COVID.

A Little Bit About the Actual Products

Pfizer and Moderna make COVID vaccines with this new technology. So far it appears to be fairly safe, and something like 90 million have been immunized in the US with at least one dose of this 2-dose regimen, so it's looking pretty good--notwithstanding that a lot of people have reported to me that they got some uncomfortable symptoms (fatigue, fevers, chills) from them. This has also been widely reported in the media. So I find people setting aside a day to recover from their shots, especially the second one. I've seen some people miss a day of work for this reason. 

The Johnson & Johnson and Astra-Zeneca products use a more familiar technology that uses DNA in a harmless virus to do the same thing in one shot. I don't have as many reports to work from, but so far it seems the side effects are less bothersome. It's hard to say what's going to happen with Astra-Zeneca's product, as there have been controversies among experts about its effectiveness, so it isn't available yet in the US. However both of these "DNA-adenovirus" products seem to be very effective at preventing serious disease. Overall, the 2-shot mRNA vaccines seem a bit more effective than the DNA-adenovirus vaccines, but the latter require only one shot and may have fewer side effects. 

"Are you going to get it?"

That's a question I get a lot. People figure that if the alternative medicine homeopathic guy gets it, there must be a good reason. It's complicated, and that takes me to the social issues surrounding mass coronavirus immunization.

I believe that having been vaccinated will become a marker of sorts for whom to trust, who can come into our "bubbles", who is a "good person" and who is a "bad person." I believe the collective mental scar from this past year and over a half-million people dead will become an enduring driver of public opinion, occupational policy, medical approaches, and administrative law. I don't know if it will be permanent, but already I am hearing about companies that will require vaccination for in-person work. I'm sure my incoming class in the fall will all be required to have been immunized in order to be in the nursing program. Hospitals will be even more dictatorial about corornavirus vaccination than they have been about flu vaccination. If immunity turns out to be long lasting, those demands may fade with time, but by that time, most Americans will have been vaccinated, either by choice or because they had to in order to keep their jobs, their place in school, and so on.

I don't believe that every school and every workplace will require it. That's harder to enforce, but I predict that it will become common for many social points of contact to demand proof of immunization before a person can [fill in the blank] with "get a job", "stay in school", or "fly on a plane" as examples. 

There will be resistance to this effort for sure--this is America, where we are often contrarian by dint of our culture! But you can bet there will be change.

More interesting is that I have begun to see individuals share that they will only consort with people who have been immunized. There's a lot of fear out there, and I'm not saying it is unjustified, but fear is on a spectrum from "foolhardy disregard" to "paralyzed panic", and I wonder how many folks are at the "paralyzed panic" end of the spectrum, and thus how common shaming of the unvaccinated might become, and how it will amplify our already-agitated social state. 

Somewhere on that spectrum is "wary regard of potential hazard"--That's where a lot of people are. That's where I've been. 

I have seen a lot of shaming of people not wearing masks. Some of those unmasked folks might be in the "foolhardy disregard" category, but some of them have medical issues that make mask-wearing difficult or dangerous--yet they too are shamed, because we see a thing and we form an instant (and uninformed) opinion. I am betting the same thing will happen with coronavirus vaccination status. One can easily see that choosing to get the shot may come down to concerns other than one's health, or risk-to-benefit analysis!

So, will I get the vaccine? If I do, it'll likely be the J&J product; I prefer drug tech that's been around for a while to tech that's brand new. That's just my experience after 30 years of practice. But will I get it, you ask?

Well, let's just wait and see.

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