What You Need to Know: Moderna vs Pfizer BioNTech vaccines

For this week’s COVID-19 Vaccine updates I want to first acknowledge that we’ve reached a total of 12 million COVID 19 cases here in the United States as of November 23, 2020. That is of course the highest amount of cases for any single country in the world.

Last week we talked about the Pfizer BioNtech messenger RNA vaccine which has now been updated from 90% effective to 95% effective by the company from its current data. They have also applied for the FDA emergency use rule. In the meantime, we now have Moderna’s  messenger RNA vaccine touted at a 94.5% efficacy rating, again by their trial data. All the data being reported of course will need third party and the usual vigorous scientific review when they are completely released to the public.

Here is what we currently know comparing the 2 vaccines. Let me draw out a comparison.  The Pfizer BioNtech vaccine and Moderna’s vaccine both  utilize messenger RNA which we explained  previously is the working copy of DNA which viruses don’t have, and are delivered to the working part of our cells or the cytoplasm encased in a lipid bilayer.  Incidentally our DNA is housed in the nucleotide area of our cells and in theory would  not interact with the messenger RNA in the cytosol. The messenger RNA interacts with the protein producing factories called ribosomes and the ribosomal factory follows the messenger RNA “blueprint” to produce a protein, in this case a SARS COV2 spike protein, and it is this protein that the body reacts to. It causes B white cells to make, activates CD4 T white blood cells, and CD8 T white blood cells.

Both vaccines require 2 doses to complete the vaccination process.  The Pfizer BioNTech vaccine is given on day 1 and then on day 22 (21 days or 3 weeks later). The Moderna vaccine is given on day 1 and then 29 days later. Moderna recently announced that their vaccine was not only 94.5 % effective but that it could be stored at 25 degrees Fahrenheit for 1 month which is much easier transport and distribute as this temperature can be maintained in most hospital and clinic refrigerators whereas minus 94 degrees fahrenheit can be more a challenge for the Pfizer BioNtech vaccine.

The Pfizer BioNtech vaccine however, can be stored at 25 degrees fahrenheit for 5 days and if stored at minus 94 degrees can last 6 months There are other differences between the two vaccines. The average onset of any symptoms such as fever or fatigue was seen 7 days after administration for the Pfizer BioNtech vaccine while for the Moderna vaccine the onset of any symptoms typically weren’t seen until day 14 after administration.  With the onset of symptoms the subjects were tested for COVID-19 infection.

In the Moderna study, the study design called for 30.000 subjects randomized and double blinded (both the subjects and the investigators didn’t know who actually got the vaccine)  to receive either placebo or the vaccine.  11,000 subjects were from communities of color, 7,000 were over the age of 65, and 5,000 were under the age of 65 but had health risks such as obesity or diabetes ( comorbidities). Half of the 30,000 enrolled subjects got the vaccine and the other half got placebo (no vaccine). The subjects got injections on day 1 and day 29 and were told to call in to report any symptoms especially fever, fatigue, shortness of breath, loss of smell, diarrhea, etc. The callers were then tested for COVID-19. After 95 subjects were found to have COVID-19 , per study design protocols, the  investigators were unblinded and the data examined by a third party, not Moderna of course.  When they looked at the  95 cases , it was found that 90 of the COVID -19 subjects got the placebo and only 5 had gotten the vaccine.

Now what is interesting is that in the Pfizer BioNtech data there were no reported severe cases but in the Moderna study it was found that 11 subjects had severe cases and all these 11 had received the placebo. None of the 5 cases of COVID 19 positive subjects with the vaccine had any severe cases. the rest of the positive cases were form the placebo group. This is promising news because the effectiveness of the Moderna vaccine appears to be 95% effective and when even infections occur there appears to be a protective effect against getting a more severe case of COVID-19. Statistically both vaccines appear to be about 95% effective in prevention of getting COVID-19.

We do not know however if they prevent infection or if people that are exposed can still pass the virus on to others. Infection results from the replication of the SARS-COV 2 virus in the body. Being infected may or may not result in any symptoms or disease. Viral shedding and therefore transmission to other people may occur even if the disease does not develop. These studies only looked at prevention of symptoms from use of the vaccine but nothing about sterilization of infection or eliminating transmissibility of the virus in the infected person.  If the vaccine could prevent infection then we would see a drop in transmissibility of the virus and it would go a long way to generating herd immunity. This would be where the vaccine prevents the person exposed with the virus to not only be protected from symptoms but also not further spread the virus to other people. If the vaccines only prevented the symptoms but had no effect on spread of the virus to other people then hospitalizations may drop but asymptomatic spread of the virus would continue and susceptible hosts with significant comorbidities especially non vaccinated hosts might succumb to severe disease and the virus would continue to spread.  In terms of safety the data monitoring committee has not reported any significant safety issues with either vaccine. Pfizer has stated more safety data will be released in the next few weeks.

Moderna has given a little more information about the side effects that their subjects experienced after they were vaccinated. These in general were mild and relatively brief and similar to other viral or flu vaccines and included fatigue, myalgias, arthralgias, headache, pain, and redness at the infection site.  So you can see the differences and similarities depicted here clearly. They both prevent symptoms and disease effectively at 95% efficacy however we don’t know if they will prevent infection or spread of the disease. They both seem to have limited side effects and so far seem safe but long term safety data is not available. We also don’t know how long the protection will last.

AstraZeneca in partnership with Oxford just announced that their vaccine is at least 70% to 90% effective. We will examine this vaccine as well as the Johnson & Johnson vaccines in our next discussions. These of course are not messenger RNAs so it’ll be a different discussion for sure. I hope you’ll join me next time.

If you want to learn about how functional medicine can help you with gut health, brain health, or immune health, you can contact us at info@jeffreymarkmd.com or  call (925) 736-9828.

For comments, questions or if you wish to learn more about AFH  supplements. You can call us at (925) 736-9828 or email us at info@jeffreymarkmd.com. Take care and stay healthy.

Jeffrey Mark, M.D.

Helping clients with compassionate and comprehensive medical care for over 25 years with 4 board certifications in functional medicine, gastroenterology, internal medicine, and anti-aging/ regenerative medicine . IFMCP, ABIM Gastroenterology, NPAS Internal Medicine, ABAARM.