This blog is the second in a 2-part series on COVID vaccines. Part one focused on weighing risk associated with COVID-19 infection against risk seen so far with vaccination. Here we’ll cover frequently asked questions about the COVID vaccines. Feel free to skip ahead to part 3, where we discuss ways to prepare your body for vaccination, as well as minimize COVID vaccine side effects.
Before we get started, I want to reiterate that I’m not a scientist or an infectious disease or vaccine expert. I’m a practicing naturopath with a strong nerd streak, and am sharing what I’m learning as I work on making an informed decision for myself.
Don’t Vaccines Contain Mercury, Aluminum, Formaldehyde and Egg Protein?
Aluminum salt is the most commonly used adjuvant in vaccines; adjuvants are used to enhance immune response. Fortunately, messenger RNA-based (mRNA) vaccines (Moderna and Pfizer), do not require an adjuvant, so they are aluminum-free. Johnson & Johnson and a vaccine from AstraZeneca that will likely hit the market soon, are also aluminum-free. (Not much information is available yet on a fifth vaccine by Novavax, which is expected sometime this summer.)
Thimerosal, which is approximately 50% mercury by weight, has been one of the most widely used preservatives in vaccines, but all 4 of the vaccines discussed here are also free of thimerosal, one reason why refrigeration/freezing are necessary for stabilization.
Formaldehyde’s role in a flu shot is to inactivate toxins from viruses and bacteria that may contaminate the vaccine during production, but the COVID vaccines discussed here all use sugars, salts and acids for this purpose (ingredients links to all 4 vaccines are below).
Egg protein is commonly used to make flu vaccines, but according to scientists, because of differing receptors and other characteristics, the novel coronavirus isn’t able to replicate inside eggs, so all are egg-free.
None of this rules out other ingredients of concern. The anaphylactic reaction seen in both of the mRNA vaccines (Moderna and Pfizer) has been widely blamed on the polyethylene glycol (PEG) both vaccines contain. PEG is a petroleum derivative found in Miralax (a commonly used osmotic laxative) that is known to cause mast cells to degranulate and release histamine. However, allergy experts suspect there may be more than one cause for the reactions, citing incomplete information about those who reacted, including blood and lab tests to determine if symptoms were allergic in nature or had another cause.
Another ingredient of concern found in Johnson & Johnson and AstraZeneca vaccines, polysorbate 80, is a common excipient and solubilizing agent used in the pharmaceutical industry that has also been associated with anaphylactic-type, as well as injection site reactions.
Over 90% of anaphylactic reactions occurred within 30 minutes following injection (some occurred up to a few hours later). Vaccination sites are now observing patients for 15 minutes post-vaccine, but some experts suggest waiting an additional 15 minutes before leaving the area.
How do the Vaccines Work?
Moderna and Pfizer (mRNA):
After injection, mRNA enters the cytoplasm of the cells (mRNA never accesses the nucleus of the cell, where our DNA is stored), where it provides instructions for the body’s own protein manufacturing process to make the partial spike protein that is central to the coronavirus’s ability to access and infect our cells. Once the viral spike protein is made, mRNA is broken down and removed permanently from the body. The partial spike protein goes on to simulate T-cells to attack the virus inside cells, as well as antibodies that attack viruses outside cells.
Though they create a nearly identical immune defense against COVID-19, the Pfizer vaccine uses 30mg of mRNA per dose, while Moderna uses 100mg, which is believed to be the reason Moderna vaccine is known to cause more serious short-term side effects.
Johnson & Johnson and Astra Zeneca (Adenovirus):
Many vaccines use a weakened or inactivated form of the target pathogen to trigger an immune response, however these vaccines use a modified adenovirus, the virus that causes the common cold, to deliver genetic instructions into our cells to make the spike protein antigen, triggering production of antibodies and a resulting immune response.
To see a side by side comparison of these 4 vaccines, click here.
Can COVID vaccines Cause/Contribute to Autoimmunity?
Since it takes years for autoimmune conditions to develop, we won’t have this answer for some time, however, there is a growing body of research to suggest that those who suffer from Long Hauler’s Syndrome (AKA Long COVID) following COVID infection, are developing autoimmune conditions.
Some scientists believe that because coronavisuses contain a lot of genetic material, they produce a large number of proteins that get dumped into your system during active infection. Since all of these are seen as foreign, the immune system will attempt to build antibodies to all of it, increasing the risk that some of these antibodies will go on to attack native (self) tissues. There is already scientific evidence that lupus, psoriatic arthritis, some types of rheumatoid arthritis and multiple sclerosis (all autoimmune conditions) can be triggered by infection.
Because the vaccines are developed to direct the cells to create an immune response against only the most critical viral protein, it’s a more targeted process, which scientists say could mean a lesser likelihood of autoimmunity developing.
Do I need the vaccine if I’ve had COVID?
Vaccines are currently recommended for those previously infected with COVID-19 because historically, only about 50% of people infected with other coronaviruses have gone on to develop long-term immunity. However, we’re learning that aside from antibodies against the spike protein, there are other measurable components that comprise durable immunity from COVID-19, among them, virus-specific memory B cells and T cells (CD4+ and CD8+).
Recent research funded jointly by NIH’s National Institute of Allergy and Infectious Diseases and National Cancer Institute, found that *95% of the 188 people studied had at least 3 out of 4 immune-system components that could recognize SARS-CoV-2 up to 8 months after infection. Findings were published on January 6, 2021 in the journal Science.
Additionally, data is starting to accumulate that shows those who have been previously infected with COVID are developing 10-45 times the immune response after only one vaccination as compared to those who have never been infected and have received 2 doses.
*This makes sense, since one year into this pandemic, we know the incidences of those contracting COVID-19 a second time are rare, and even rarer, within 90 days of initial infection. Since COVID-19 stimulates the development of such a large array of antibodies, it seems like it would be worth waiting for at least 90 days after infection (whether or not you’ve had monoclonal antibodies or convalescent plasma) before goosing your immune system with a vaccine. It took quite some time Googling, but I did find Mayo Clinic also recommends waiting 90 days. This will give us time to learn more about lasting immunity from COVID-19 infection as well as adverse events associated with vaccinating those who have recovered.
Did the Faster Production of the Vaccines Compromise Safety?
There are numerous reasons we were able to bring vaccines to the market more quickly than ever before.
- The federal government invested $10 billion on development. This meant we started out with more vaccine candidates, some of which failed along the way. However, rather than starting with just one option, and starting over from scratch if it failed, we had more odds of hitting a home run.
- Steps that are typically done sequentially were done simultaneously
- While animal trials were still a first step, they were shortened, and there are many in the scientific field who think this change may become a new norm since the vast majority of new drugs fail once they move into human studies, despite appearing safe and effective in costly and lengthy animal trials. For those concerned with animal welfare, there are exciting changes coming in the development of effective medical advancements that may move us away from animal trials.
- Though we’re now seeing our first messenger RNA vaccines roll out across the country, the technology to perfect them began in 1990, and was finalized in 2018
- Finding infected human subjects was much easier with COVID-19 than for most studied infections because of its high rates of transmissibility
- Most previous vaccines have been protein-based, which is a much more complex process, requiring more time solving manufacturing issues. The manufacturing process for mRNA-based vaccines is more straightforward (once scientists worked out all the manufacturing issues in previous years of research), which streamlined the approval process. There are also protein-based COVID vaccines in the works, but they’re taking longer in manufacturing
- Vaccine developers started the manufacturing process while awaiting results of final clinical trials and approval. This was a gamble, since the vaccines produced prior to approval could have been wasted time and money, but they allowed for vaccine roll-out to happen more quickly
- Also, to speed up approval, larger safety trials were done on the COVID mRNA vaccines than are typically done, which amassed much more safety data than is typically available on a new vaccine. Like any new drug, however, once rolled out to a larger population, more unusual reactions are and will continue to be seen.
- Emergency use authorization is a quicker process that takes into consideration the risk of harm should a drug be delayed in reaching the public.
If you have a question about COVID-19 vaccines, please add it in the comments below, and I’ll do my best to answer it. Remember, I see patients in practice, so it may take me some time.
To continue to part 3 in this series, click here.