Dr. Caleb Patee, Work Right’s medical director shares some insight into the new COVID vaccination and answers some common questions on each of the vaccines as well as common, typical side effects.

COVID Vaccination Series:

Currently there are three (3) FDA emergency use approved vaccines for the coronavirus, Pfizer, Moderna, and Johnson and Johnson (J&J). There are slight variances in mechanism and efficacy between these vaccines. 

COVID vaccine, RNA, Pfizer, Moderna

Pfizer and Moderna

These vaccines utilize a piece of messenger RNA that codes for the spike protein, a component of the covid virus. These proteins cause our body to develop antibodies that allow us to fight future exposures to this same spike protein. This reduces the time from exposure to activation and deployment of our illness fighting cells. 

Johnson and Johnson

This is a carrier vaccine that utilizes an innate or harmless virus to deliver DNA strands that instruct the cell to create spike proteins. This is a two step process compared to mRNA strain, as our body does have to convert the DNA to mRNA to develop the spike proteins. In a similar response to the Moderna and Pfizer vaccine, the body responds to these proteins by making antibodies. 

AstraZeneca and Novavax

These use different mechanisms to provide either DNA instructions (AstraZeneca) or a portion of the spike protein (novavax) to develop an immune response. That said, both of these vaccines are still in earlier stages of development and have not been FDA approved for emergency use.

Post Vaccine Expectations

Each vaccine is attempting to create a rapid response team to fight off future exposures. In order to develop this team, the vaccines create a safe training zone. This training activates our immune system and teaches them what to look for. The results of this are typical effects seen by an activated immune system; fatigue (62%), fevers (14%), headaches (55%), muscle and joint pain (40%), redness and pain (85%) at the injection site. On rare occasions, the body can over react to an immunization resulting in prolonged fevers, shortness of breath, swelling or closing of the airway. Many of these will require prolonged observation and or emergency intervention and if experienced should seek medication attention. These events are rare (11/1 million) and the CDC does recommend that if someone has a history of anaphylaxis or excessive immune response to prior injections or immunizations to be observed for longer. 

There have been increasing reports of immune effects with the second vaccination. This would not be surprising, as the body has already created an initial rapid response team. This response is helping to demonstrate an appropriate reaction to the abnormal protein expression. 

The CDC has developed a great short and long term monitoring program to track side effects from immunizations called V-Safe (vsafe.cdc.gov). This program is free and provides daily health check ins for the first week, then weekly for 5 weeks, then once at 3 month, 6 month, and 12 month time frame. This information is used to update common side effects and adverse events. 



  1. https://www.cdc.gov/coronavirus/2019-ncov/vaccines/different-vaccines.html 
  2. https://www.cdc.gov/coronavirus/2019-ncov/vaccines/safety/vsafe.html 
  3. https://www.cdc.gov/vaccines/covid-19/info-by-product/pfizer/index.html
  4. https://www.cdc.gov/vaccines/covid-19/info-by-product/moderna/index.html 
  5. https://www.cdc.gov/vaccines/covid-19/info-by-product/janssen/index.html 
  6. https://www.fda.gov/media/144414/download 
  7. https://www.fda.gov/media/144638/download 
  8. https://www.fda.gov/media/146305/download 
  9. https://www.health.harvard.edu/blog/covid-19-vaccines-safety-side-effects-and-coincidence-2021020821906