With the release of the new Covid vaccines, I thought it would be good to look at these two vaccines, review some of our previous discussions of vaccination, and dispel a few myths.
The Vaccines
There have been two vaccines against Covid-19 approved for use in the United States; one made by a partnership between the companies Pfizer (US), BioNTech (German), and Fosun (Chinese), and one made by a partnership between the company Moderna and several US government agencies. The former (which I will call the Pfizer vaccine from now on for brevity) has been approved for use in 14 countries (counting the EU), while the Moderna vaccine has so far only been approved for use in the United States and Canada.
Both vaccines are examples of mRNA vaccines. As discussed before, this means the vaccine consists of a bit of Covid-19 genetic code protected inside a bubble of fat. The cells of the patient’s body absorb the bubble, use the bit of Covid RNA as instructions to construct coronavirus proteins, and release these proteins into the bloodstream. The immune system believes this ever growing amount of Covid proteins is a sign of infection and creates an antibody response that is also effective against the Covid-19 virus. These two vaccines are the first examples of genetic vaccines approved for use in humans, but the tremendous amounts of research done since even my original post seem to have disproven most of our previous concerns about this method, as genetic vaccines appear to be as safe as traditional vaccines.
The major disadvantage of mRNA vaccines is one of storage; RNA is much more delicate than the components of traditional vaccines, so these vaccines must be stored at lower temperatures. The Moderna vaccine will need to be stored at roughly -20°C (-4°F, or the temperature of an average home freezer), while the Pfizer vaccine will need to be stored at roughly -70°C (-94°F, or slightly above the freezing temperature of dry ice). It already takes specialized infrastructure to transport and store cold sensitive goods, doing so for super-cold sensitive goods like the Pfizer vaccine will necessitate stretching extremely specialized infrastructure to its very limits. Keep in mind these vaccines also have to be delivered and used in developing nations, where cold storage and timely transport are less reliable. The current plan is to use the Pfizer vaccine in predominantly urban areas, where super-cold storage is more common and higher population density means the vaccines won’t have to be stored as long. Meanwhile, the Moderna vaccine will be reserved for more rural areas, where traditional cold storage can be used. Governments and various shipping and storage companies have spent months preparing for this mass inoculation. But no matter what, this will be a one of, if not the biggest logistical challenges in recent history.
Both of these vaccines require two doses, taken about two to three weeks apart, in order to be effective. We’ve discussed before why certain vaccines require booster shots, and it’s the same case here. For any vaccine to be effective, the immune system needs to believe it is a legitimate infection that poses a real threat to the body. It can be difficult to simulate such an infection that doesn’t actually pose a real threat to the body, so one method is to have multiple small infections in rapid succession that don’t threaten the body individually, but together convince the immune system that they collectively represent a significant risk. Taking only one dose of either the Pfizer or Moderna vaccines only prevent about 50% of Covid infections. Taking two prevents about 95% of infections. So it is important to get both recommended injections and don’t stop wearing a mask or social distancing after receiving the first dose! Also, it can take up to two weeks after inoculation to develop the full immune response, so don’t stop wearing a mask or social distancing immediately after receiving the second dose! As an act of precaution, it is best to not break quarantine until health experts begin telling us it’s safe to do so. While this vaccine will definitely make you and everyone safer, the risks created by this pandemic are too great to be flippant.
Dispelling Misconceptions
I’m going to avoid talking about the truly ridiculous myths floating around as even mentioning them would be giving them more credence than they deserve. But suffice to say, neither vaccine contains tracking devices. You can already be tracked by your cell phone, so such a tracker would be redundant.
Rapid Development...possibly too rapid
These vaccines have been through the fastest approval process of any vaccine in history. So it’s...not unreasonable to have some healthy suspicion. That said, while the approval process for both vaccines was accelerated, they both went through all the same steps as any other vaccine. I’ve talked before about the stages of vaccine development and how they could be accelerated if it became necessary. The Pfizer vaccine combined its Phase II and Phase III clinical trials into one trial with 43,000 participants, each of which were monitored for two months for any side effects. These combined trials aren’t normally done because these trials are expensive and no one wants to pay for the Phase III trials of a drug that fails its Phase II trials. But with the near limitless funding given to Covid research, money was less of a concern. Both drugs also had their approval processes expedited by the FDA and other regulatory bodies. This doesn’t mean these regulators skipped steps, it means these vaccines were moved to the top of the list instead of being approved on a ‘first come first serve’ basis. It should also be noted that researchers weren’t starting from scratch when developing these vaccines. Scientific resources were poured into the original SARS pandemic in 2002, but that pandemic fizzled out on its own before a vaccine could be finished. Covid-19 is very closely related to the original SARS, so much of that research could be repurposed, resulting in a shorter initial development phase. With enough resources dedicated to a single goal, anything can be made to go faster than you would believe possible.
Side Effects
The listed side effects for either vaccine are redness at the injection site, headache, fever, fatigue, chills, and muscle and joint pain. It is important to note that these are also the side effects of many vaccines, occur in less than 10% of patients, and typically last less than a day. All vaccines contain two components; the antigen (the part we’ve been talking about) and an immunological adjuvant. An adjuvant is any substance which increases the activity of the immune system, so it responds more aggressively to the antigen and builds a stronger immune response. These side effects are caused by having a hyperactive immune system spurred by the adjuvant. Without these adjuvant agents, all vaccines would be far less effective. Furthermore, the side effects of either Covid vaccine are no more severe than that of other vaccines.
There have been reported cases of recipients of these vaccines going into anaphylaxis, the same response associated with food allergies. The reaction is believed to be to polyethylene glycol (PEG), a petroleum substance that coats the outside of the bubble of fat containing the RNA in order to make it more stable. Allergic reactions to PEG do occur in some people and research is being done into exactly how common this particular allergy is. That said, PEG is an extremely common stabilizer in many drugs. It is used in laxatives, shampoos, and toothpastes and the vaccine will deliver less PEG to a person’s bloodstream than many other drugs would. Now, if you have been diagnosed with an allergy to PEG, ask your doctor about taking this vaccine. But this is an extremely rare response; of the over 200,000 Americans to have received this vaccine, six have experienced this reaction. This is technically not enough data points to definitively confirm there’s a link between the allergic reaction and PEG, or anything else for that matter. That said, this is a new vaccine technology being used for mass inoculation, so doctors and researchers are still taking this potential risk seriously. This is why they’re recommending that anyone with a history of anaphylaxis should wait for thirty minutes after being vaccinated so they can be monitored and treated if anything happens.
mRNA Vaccination Technology
These two vaccines are the first two genetic vaccines to be used in humans. With any new technology, there’s room for reasonable concern about said technology’s safety, and the researchers who developed these vaccines have certainly taken these risks seriously. But there is no risk whatsoever that either vaccine will incorporate itself into your DNA and alter your genome because neither vaccine uses DNA.
At some point in the future, I would like to do a very brief high-level summary of how the genome works. But to be as brief as possible, there are two types of genetic material in your cells; DNA and RNA. These are both chains of molecules which encode information, specifically, how to construct and regulate proteins. DNA is a very stable molecule, meaning it lasts a long time and won’t break down in the cell’s normal environment. Because it lasts so long, DNA is used by the cells to write out the library which is our genome. All the instructions to run a cell are written out in DNA and permanently stored in the cell’s nucleus. By contrast, RNA is very short-lived, breaking down after only a few minutes inside the cell. This makes it useful as a way to send messages throughout the cell. A cell’s DNA is used as a template to make an RNA copy of the same information, which then travels to machinery outside the nucleus where it is used as instructions to make proteins. It’s the equivalent of making a rubbing of a stone inscription before mailing it to someone who uses the rubbing as a blueprint.
While DNA is used as instructions to make RNA, RNA cannot be easily re-transcribed into DNA*. This means the mRNAs released into the cell by the Covid vaccines can’t be incorporated into the genome since they’re written in incompatible molecules. What will happen is that the machinery of the cell will use these mRNA molecules as instructions to manufacture coronavirus proteins. These proteins will be released into the bloodstream where they will resemble a viral infection to the now hyperactive immune system. Genetic vaccines have the potential to be an extremely safe and effective technique to inoculate against disease. Because it’s only a few viral proteins that are made instead of the entire virus, there’s no risk of the vaccine causing a legitimate infection. This technique also has the advantage of being comparatively easy to manufacture. I’ve talked before about how mass production of vaccines requires growing massive amounts of the virus, which is very difficult even under the best of circumstances. Comparatively, cloning DNA in a lab is far easier (I did it as part of my undergraduate work, though we were using a simpler technique than the one used to make this vaccine). This new technology has a lot of potential that we’ve only just begun to use.
Absolutely none of this is to say that this pandemic is over. This video by Wendover Productions talks about the logistics of distributing this vaccine to everyone on Earth, which will not be easy. (Please note this video was made in September 2020 and therefore refers to future events that we are currently experiencing.) These vaccines mark the very beginning of the third act, not the ending. So it is important to continue to wear masks, social distance, and listen to experts on what is safe. But there is light at the end of the tunnel and we are getting close enough to see it.
*RNA can be re-transcribed into DNA using specialized proteins, but these proteins are not naturally found in human cells.
For More Details
https://www.mayoclinic.org/diseases-conditions/coronavirus/in-depth/coronavirus-vaccine/art-20484859
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