Pfizer vs Moderna: What are the Differences

Is One COVID Vaccine Better than the Other?

Pfizer and Moderna vaccines are very similar. They are both mRNA vaccines administered in 2 doses within a month. The end result will be the same for both, with 95% protection after your second dose. So one is not better than the other. If you decide to get the vaccine, chose whichever one you feel comfortable with. The FDA recommends Moderna 20-0 for the vaccine of choice based on the amount of available research. This may change as we learn more information about Pfizer.

What are the differences between the vaccines? Pfizer is slightly less effective after the initial dose, with ~52% protection. Moderna reported 80% protection with their initial dose. Moderna does administer a larger dose of 100mcg for both doses, and the second dose is administered after 28 days. On the other hand, Pfizer administers 30mcg for both doses and recommends administering the second dose 21 days after the first.

Pfizer	Moderna
52% protection after 1st dose	80% protection after 1st dose
2 x 30 mcg IM injections	2 x 100 mcg IM injections
2nd dose given after 21 days	2nd dose given after 28 days
95% protection after 2nd dose	95% protection after 2nd dose

The only 2 vaccine options available as of January 2021 are Pfizer (BNT-162b2) and Moderna (mRNA-1273). Currently (as of February 2021), only high-risk populations are allowed to get the vaccine, which are healthcare providers and the elderly population.

What is an mRNA Vaccine?

Vaccines traditionally contain either weakened viruses or purified signature proteins of the virus, which is what some of the upcoming vaccine options are using. Johnson & Johnson’s COVID vaccine uses a viral vector while Novavax uses a protein subunit. Pfizer and Moderna are mRNA vaccines. Instead of injecting a viral protein, they are injecting mRNA genetic material into the body.

If most vaccines are made from viruses or proteins, why are they using mRNA? Let’s talk about how an mRNA vaccine works? COVID is an RNA virus, so the vaccine mimics what the virus does to our body in real life. After the vaccine is injected, your body produces a part of the viral proteins that are in the COVID virus.

Will the vaccine give you COVID? The mRNA only tells the body to produce a specific fragment of the COVID viral protein. Have you heard them talk about the spikes on the surface of the virus? That is what your body produces, the harmless spikes.

How does the vaccine produce antibodies? Our body recognizes the vaccine as an unwanted invader and starts producing antibodies to protect itself. Well, now your body had a sneak preview of how the virus works. It will already have antibodies to fight against COVID and you are more likely to experience mild symptoms. The virus does not prevent you from getting COVID, it prevents severe illness.

Common COVID Vaccine Side Effects

If you get the vaccine, report any side effects you experience to Vsafe. They are tracking all of the effects there. Both vaccines are known to cause similar side effects. The most common side effects are fatigue (feeling tired), headaches, fever, chills, joint pain, and muscle pain. Both of the vaccines are causing redness at injection sites, mild asthma flareups, swelling, etc. A rare but serious potential side effect from either vaccine is a severe allergic reaction. These usually occur in someone with severe food or drug allergies.

Each vaccine has a few unique side effects. For example, Pfizer is linked to rare occurrences of Bell’s Palsy. This is rare but possible. If you are a woman with facial filler you may experience mild facial swelling, but these were easily managed with Benadryl and over the counter medications. Many are experiencing swollen lymph nodes after the second Moderna dose.

I know a few healthcare workers who tested positive for COVID after the first dose, and some after their second dose. We do not feel as if the vaccine caused COVID, but that they were already exposed before getting the first vaccine. You are not 100% protected, even after the 2nd dose, so it is possible to get COVID after getting the vaccine. The hope is the vaccine will decrease the severity of your COVID symptoms. TBD!

So, YES! Unfortunately, you still need to wear a mask. I really hope we learn enough to effectively manage the symptoms or discover a vaccine that allows us to return to normal life. I know I am not alone, I do not like the new normal.

Who Should Not Get the COVID Vaccine?

Anyone who has severe food and drug allergies is at risk for serious side effects from both vaccines. Pregnant women should reconsider the vaccine since both the WHO and American College of Obstetrics and Gynecology (ACOG) only recommend high-risk patients to receive the vaccine when the benefits outweigh the risks. Asthma is not an eliminating factor but consider the risk. If you feel like your asthma is severe enough that you would be at risk, consult with your primary care before getting the vaccine.

What Are the Unknowns?

As we follow vaccine recipients we will know how long they are protected. Will you need a booster to remain protected? How often will you need a booster? This is a guarantee, but the timeline for when this will be necessary is unknown. These are all things that will be determined as we learn more.

What are the side effects? we know what people are experiencing, but we are learning more every day. This is truly a live research study with the entire world. Make sure you report your side effects to Vsafe. At least this will allow us to know more about the unknowns.

Will the Vaccine Be Effective Against Mutated Strains

Both Moderna and Pfizer are working on a booster that will be effective against the mutated strains of COVID. No one is saying if the current 2 dose vaccines will or will not be effective. If they are developing a booster to target the mutations, this suggests they are questioning if it will be effective? We are our own research study. What happens in the patient population receiving the vaccine will determine what side effects occur and if it works against the mutated strains. I guess time will tell.

Final Thoughts About the Vaccines

We are all in this together. With so many unknowns it is difficult for us all. If you want to know if you are a good candidate for the vaccine visit my post “How to Determine If You Should Get the Vaccine”.