Questions about the Covid-19 Vaccine: Answered
Since our last blog about the Covid-19 vaccines, which detailed the ingredients, more research and information has been published about the Pfizer and Moderna vaccinations. Further, as of January 27, 2021, 71.1 million people have been vaccinated, providing valuable data in regards to side-effects and the potential for mast cell activation and allergic reactions.
The idea of a new vaccine, especially one that was released with much less research than previous vaccines, may raise concerns and fear. And rightly so. In this blog, we will answer some questions you may have about the Covid-19 vaccines.
How do mRNA vaccines work?
Pfizer and Moderna’s mRNA vaccines work the same way. The lab-created genetic code in the mRNA sends information into your cells on how to temporarily manufacture a spike protein, which is found on the outside of the coronavirus. For more information about how the spike protein functions in a Covid infection, click here. When cells receive the mRNA genetic code, they absorb it and send it to the ribosome which then begins to manufacture the protein. After the spike protein is released, our immune system develops T and B cells (antibodies) to attack the spike protein.
These antibodies are created to recognize and remember the Covid-19 specific spike protein, so in the future, if you encounter it, your cells will attack and easily destroy the coronavirus. However, because the mRNA does NOT change your DNA, the immunity provided by an mRNA vaccine will not last forever.
Why do I need two doses of the Covid-19 vaccine?
The first dose of the Covid-19 vaccine is when mRNA is introduced into your cells, and the ability to recognize the virus is created. This process takes 2-3 weeks, explaining the delay between the two shots.
The second dose of the vaccine assists the immune system in building your long-term defenses against the virus. The second shot brings the effectiveness up from only 50% after the first shot to the final total of 95%.
How long will the vaccine last?
Most estimates calculate the immunity provided by the vaccine will last only 6-12 months.
If I’ve already had Covid-19, do I still need to get the vaccine?
Yes, the naturally occurring immunity given by Covid-19 antibodies only last 2-3 months. The possibility of getting a second infection rises after that period. Further, the covid-19 antibodies are only effective against whatever strain you had, it will not carry over into new variants. The Covid-19 vaccination, however, is expected to work against all variants.
What’s the difference between the Pfizer and Moderna vaccines?
While the Moderna and Pfizer vaccines are mostly the same, they have several differences.
Moderna:
94.1% effective
mRNA encodes for the entire spike protein on the surface of the virus
2 shots are taken 28 days apart
recommended for people 18+
stored at a freezer temperature of -4 degrees
after thawed, the vaccine can be refrigerated for an additional 30 days
Pfizer:
95% effective
mRNA encodes for a portion of the spike protein on the surface of the virus
2 shots are taken 21 days apart
recommended for people 16+
stored at a freezer temperature of -94 degrees
the vaccine can be refrigerated for 5 days, but must be used within 6 hours after thawing
For both vaccines, if you go longer than the recommended time between shots, you will not have to get the first dose again. You must stay consistent with the brand of vaccine you get. You cannot get the 1st dose of Pfizer and the 2nd of Moderna.
What is the risk of mast cell activation and allergic reaction?
The risk for mast cell activation and an allergic reaction to the vaccine comes from the lipid nanoparticle encapsulation. There might be a mechanism in which these nanoparticles can cause an allergic reaction by activating mast cells. But because the Covid-19 vaccines are the only vaccines available for human use that utilize lipid nanoparticle encapsulation, more research must be done before a conclusion can be made. However, many other products, including common medications, use the lipid nanoparticle encapsulation technique. One researcher said, "one would be hard-pressed to find a first-world patient who has not been exposed to it."
How does the Covid-19 vaccine compare to the flu vaccine?
The Covid-19 vaccinations are likely to have fewer side-effects than flu vaccinations for 2 main reasons:
In the flu vaccination, more flu viruses are included as opposed to the one in Covid-19, thus exposing you to fewer potentially harmful antigens
mRNA vaccines contain even fewer proteins than the virus in flu vaccines, so they have less likelihood to trigger an immune response altogether.
What are the known side-effects?
After the first shot, you might feel some pain and minor swelling around the site of the injection with some muscle stiffness in the arm. These side-effects will usually disappear in under 24 hours. After the second shot, the immune defense is building, so flu-like symptoms with a low-grade fever, fatigue, and chills may occur. But these symptoms will disappear in around 24 hours.
With the mRNA vaccine, you are not receiving a mild case of Covid-19, as there is no actual virus in the vaccine. You are experiencing your immune system reacting the way it is supposed to when a foreign antigen is introduced.
The risk of triggering an autoimmune reaction or illness from the vaccine is 0.1%. As is the same for receiving any kind of vaccination.
What does the CDC say about the side-effects?
In regard to the Pfizer and Moderna vaccines, the CDC agrees with the European Medicines Agency, US Food and Drug Administration, and the World Health Organization- all of which agree the vaccines are safe for use. A breakdown of the side effects is below:
Pfizer: 1 American and 2 Britons experienced anaphylactic shock, with redness and shortness of breath. Manufacturers do NOT see any direct connection with the US physician with no previous illnesses who died from a brain hemorrhage 16 days after receiving the vaccine.
Moderna: The side-effects of the vaccine were mild or moderate. The most serious side effect was fatigue experienced by 10% of those who received the Moderna vaccination. Researchers noted on January 10, out of 4,041,396 doses of the vaccine, 108 allergic reactions were recorded, but only 10 people went into anaphylactic shock. No reactions led to death.
While the CDC does not advise against pregnant women or breastfeeding women taking the vaccine, children are not advised to take it.
What if I don’t want to use an mRNA vaccine?
Two vaccines are soon to be available for public immunization that do not use mRNA. Johnson & Johnson/Janssen uses a virus called Adenovirus 26 and AstraZeneca/Oxford uses a cold virus common in chimpanzees. The Johnson & Johnson/Janssen and AstraZeneca/Oxford vaccines use viruses that have the same spike proteins as the coronavirus. Both vaccines work as standard vaccinations do, using DNA instead of mRNA to cause an immune reaction, making them much more stable than the Pfizer and Moderna vaccines.
The viruses used in these vaccines can enter human cells, but CANNOT reproduce, so they will NOT lead to an infection. Instead, these viruses will enter the nuclear in a human cell, where the spike protein is copied and many more are made. Antibodies will recognize the protein as a foreign antigen and recognize to destroy it. Thus, the next time a Covid-19 spike protein is intensified, it will also be destroyed.
When will the non mRNA vaccines be available?
The Johnson & Johnson/Janssen vaccine is expected to be available in March 2021. The AstraZeneca/Oxford vaccine has not been approved by the United States yet, but it may be ready in late Spring 2021.
