Understanding the technology behind our four currently available vaccines will help you decide which vaccine is best.
Unrelenting brain fog. Disabling body aches for weeks after the fevers have cleared. Recurring daily headaches that make it hard to concentrate. Vertigo and tinnitus that you’ve never had before. If you’re young, healthy, eat well, and—especially important—have been avoiding vegetable oils, COVID is fairly mild. But when it’s not mild, it can hit hard.
If you’ve decided you’d rather get a vaccine than play roulette with a loaded virus, you’re probably wondering which vaccine is the most effective and carries the least risk.
The information here is based on CDC guidance, other medical research, and, where there is no data, on my best opinion at the moment.
Which is the best vaccine?
The CDC says “they’re all great!” But my answer is “the kind of vaccine you get makes a big safety difference.”
Our current COVID vaccines are all entirely unlike any other vaccines ever before released upon the general public. There are two types of COVID vaccines right now, both types are a distinct form of new technology that has not previously been employed to manufacture a mass-produced commercial product.
The first kind that was released (by Pfizer) is made with mRNA technology. The second kind that was released (by Johnson and Johnson) is made using viral vector technology. This is the kind that was put on pause for causing blood clots.
I recommend getting the mRNA, two-shot vaccines, and avoiding the viral vector vaccine single-shot vaccine at this point in time.
The mRNA vaccines made by Pfizer and Moderna both use mRNA technology. I was initially very skeptical of these vaccines because mRNA vaccines have never been released on the human population before and so, in a sense, this has been a big experiment. But now that so many millions of us have been subjected to this experiment with no surprises, meaning no unexpected short-term side effects, I feel a lot better about it.
Here’s how the mRNA vaccine works.
The m in mRNA stands for messenger. Messenger RNA contains instructions for making proteins, hence the term messenger, and it does not last very long once it gets inside your cells because our cells can rapidly break down the mRNA messages. This is by design; mRNA has to be rapidly broken down so cells are always making proteins based on the most recent instructions released from the nucleus, where the brains of the cell reside in the form of DNA.
Think of mRNA as what’s trending on Twitter. It changes from minute to minute and so we don’t have to worry about it sticking around very long.
The mRNA in the Pfizer and Moderna vaccines teaches your cells to make the spike protein. It may sound foolish to willingly get injected with something that takes over your cells and forces them to drop whatever they normally do and instead churn out viral spike proteins. But if we want to develop immunity to a virus, we have to allow ourselves to be exposed to at least some part of that virus.
The spike protein is a piece of the covid virus that very effectively attracts our immune system and when our immune system makes antibodies against spike proteins it very effectively beats covid. After being exposed to the spike protein, our immune system “learns” to recognize this bit of protein as foreign so if we are later infected with the real virus it will recognize the foreign invader and attack it quickly with antibodies, ideally without us ever feeling sick.
Unlike the actual COVID infection, which contains mRNA for making a whole new baby virus ready to infect more cells, the COVID mRNA vaccine just contains the instruction to make the spike protein; it can’t make the whole virus. So while getting any vaccine can make you sore and tired and achy because it can elicit an immune response, it won’t make you as sick as covid makes you. Not even close.
As mentioned, after entering your cells, mRNA is quickly broken down so your cells don’t make spike protein very long, possibly just for a few hours. Meanwhile, your immune system learns to recognize and rapidly attack spike protein, thus protecting you from covid in the future. It’s that process of learning to recognize the spike protein that makes us feel bad after a vaccine. Oh, and the 3-inch needle stabbed into your deltoid doesn’t feel great either.
How do vaccines generally work?
Most vaccines expose us to viral proteins directly. These protiens are called antigens. The flu shot, for example, contains proteins from the influenza virus and when we get a flu vaccine we are injected with flu antigens that then teach our body to fight off the flu by making antibodies. Antibodies can last for a very long time; survivors of the 1919 influenza pandemic were found to have antibodies 75 years later. So you can see our immune system has a long “memory.” The reason we need to get a different flu shot every flu season is that there’s a different flu virus with different antigens, not because our immune system “forgets” about the antibodies it made.
As a side note, antigens and antibodies sound similar and often confuse even medical students. To sort out which is which, you can try thinking like this: gens sounds like germs and antigens are made by germs like viruses, and your body makes antibodies.
The big difference between the typical flu vaccine and the mRNA covid vaccine is that instead of injecting you with viral protein you get injected with viral mRNA so your own body’s cells end up making the viral proteins that then trigger the antibody response. The mRNA vaccine is therefore a big step removed from normal vaccine technology.
The reason mRNA vaccines were released instead of normal protein-based vaccines has to do with how fast the labs could ramp up the production. To make protein, a lab would have to first make mRNA to manufacture the protein in a lab that would then need to be purified. The mRNA vaccine enables labs to skip that protein-making and refining step, and that’s why labs can generate mRNA much faster than they can generate protein.
Are vaccines safe in general?
Injecting yourself with viral proteins might seem like a foolish thing to do. But if you consider that what viruses do to us is worse, it gets less foolish sounding.
Unlike an actual viral infection, where you’re body is exposed to multiple proteins and has to figure out which one actually works to fight off the virus, the vaccine makers have done that work for us and chosen the right protein most likely to protect us. Not to mention the fact that the protein injected can’t take over our cells, can’t divide, and can’t kill us but viruses can.
Here’s how the viral vector covid vaccine works.
Now that we’ve discussed how vaccines generally work as well as the mRNA vaccine, let’s take a look at the Jansen (AKA Johnson & Johnson) and Astra Zeneca single-dose covid vaccines that use a whole different kind of technology. These two vaccines both use a modified strain of cold virus, called an adenovirus, that’s been drained of its normal contents, which would cause you to get a cold, and loaded with man-made DNA instead. This DNA teaches your cells to make the spike protein in a manner that’s similar to the way the mRNA vaccine works, but fundamentally different and more complex. Anything this complicated is more likely to cause unpleasant surprises.
First of all, the delivery vehicle, the monkey virus, is genetically modified to render it incapable of dividing in your body, we hope. It’s not totally a matter of hope; the vaccine was tested in humans, but only in a very limited way. Prior to covid, similar viral vector technology had been tested in humans and animals, though, so that’s reassuring.
Secondly, and here’s what’s unsettling, is that the vaccine contains DNA, not mRNA. DNA lasts longer than mRNA but will break down eventually, we hope. This part is pretty iffy because DNA is designed to last forever, or at least billions of years. DNA survives by replicating itself, mutating, going dormant, and it probably has a number of other tricks up its sleeve we haven’t yet discovered. DNA is the most ruthless molecule on the planet; it’s the ultimate survivor. So this aspect of this viral vector vaccine worries me.
As you can see, there are more unknowns with this type of vaccine which is why I can’t comfortably recommend it at this point in time.
Which vaccine should I get if I’m pregnant?
The official answer from the CDC is “We have no idea how these vaccines affect pregnant women. Go ask your doctor.” Nice, huh. Kind of like saying “Don’t blame us when things go wrong, we didn’t give you the shot.”
My answer is: The Pfizer and Moderna mRNA vaccines are much more likely to be safe in pregnancy, although this has barely been studied. The Jansen and Astra Zeneca single-dose vaccines have been studied even less and seem much riskier based on the kind of technology used.
The crazy thing is there is almost no research on mRNA in pregnancy. It’s especially crazy because mRNA vaccines have been in development for decades and you’d think at some point in time someone would have pointed out that we need to know if mRNA crosses the placenta. If mRNA crosses the placenta, a lot of insanely bad things might happen and the vaccine really needs to be studied very carefully before giving it to a pregnant woman. If it does not, then that’s a whole different thing.
If I had to guess, I’d say having covid in pregnancy is probably riskier than getting the vaccine, but we really don’t have any good science to support that guess.
Which vaccine is less likely to cause long-term complications?
The official answer is “Long-term complications are extremely unlikely.” And technically that’s statistically true; a one in a thousand chance of a reaction means for any individual it’s extremely unlikely. But the reality is, we can’t know. Both vaccine technologies are new, never before released on the human population, so we can’t know the answer.
That said, with other vaccines the rate of short-term complications is related to the rate of long-term expectations, and this vaccine can reasonably be expected to follow that pattern.
So, since the mRNA vaccines have had few short-term complications after more than 60 million doses and no unexpected complications, while the viral vector vaccine less than 10 million and already some deadly and unexpected blood clots, I would predict that long-term complications will also be found more frequently with the viral vector vaccine.
So Which Vaccine Did I Get?
There’s no way I personally would get the viral vector vaccine—there’s a lot I just don’t like about it. Especially when there’s what seems a much safer option. I got one of the available mRNA vaccines. I can’t remember which pharmaceutical brand, but I do remember the 2-inch, 22 gauge needle, which is longer and wider than necessary but the pharmacist said it’s what they came loaded with so I was stuck with it.
This is a little like where we’re all at with COVID: there’s plenty to complain about but, in the end, most of us are doing our best. Because that’s all any of us can do, right? Consider as much available evidence from credible sources as possible, weigh the pros against the cons, and then take your best shot.