Skip to content

Moderna and Pfizer Vaccines: How Effective is One COVID shot?

CDC Study answers this question

COVID-19 vaccine for lupus patients: One COVID shot effective?
Is just one COVID shot effective?
Please get your COVID-19 vaccine! We all would like life to go back to normal. The unvaccinated will be our major obstacle in reaching that goal. (and yes, that is my, and many others, unapologetic opinion)
QUESTION: How effective is just one COVID Shot if you did not get the second?

Type of study? A Centers for Disease Study

Where? 33 sites in 25 states (U.S. study)

Who? Health Care Provider recipients of Pfizer and Moderna vaccines

Results? One vaccine offered an 82% protection rate (Pfizer, Moderna)

94% for 2 doses. This similar to what we saw in the clinical trials

How about people with lupus, Sjogren’s and other autoimmune diseases?

– They were not studied
– However, there are active studies being done at the NIH, Johns Hopkins, etc
– If you live near Bethesda, MD, call the NIH nurses at 301-435-4489 and 301-451-4990; tell them Dr. Thomas sent you

– If you have an autoimmune disorder, especially if you are on immunosuppressant therapy, you are at higher risk of bad outcomes from COVID-19 infection.
– It is imperative you get vaccinated
– Make sure to stop your immunosuppressants appropriately for vaccination (but ask your doctor 1st to check)
Here is a link on how to stop meds for the vaccines:


– If you get vaccinated, pretend you are as vulnerable as if you did not get vaccinated
– Still practice social distancing
– Ignore the CDC guidance for others who are vaccinated… i.e. still wear your masks and socially distance from everyone and plead the unvaccinated to just stay away from you (I always worry about my patients)

REFERENCEACR, COVID-19 Vaccine Clinical Guidance Summary for Patients with Rheumatic and Musculoskeletal Diseases. Developed by the ACR COVID-19 Vaccine Clinical Guidance Task Force.

Pilishvili T, Fleming-Dutra KE, Farrar JL, et al. Interim Estimates of Vaccine Effectiveness of Pfizer-BioNTech and Moderna COVID-19 Vaccines Among Health Care Personnel — 33 U.S. Sites, January–March 2021. MMWR Morb Mortal Wkly Rep. ePub: 14 May 2021. DOI: icon.


Don Thomas, MD, author of “The Lupus Encyclopedia” and “The Lupus Secrets


  1. This has been the only thing on my mind since receiving the 2nd dose of Pfizer 30 days ago. I’m concerned because I wasn’t told to stop or hold any meds after taking each dose of the vaccines. I would hope that all rheumatologist are having these discussions with their patients. Thanks for sharing and your guidance.

  2. I am part of the Study with John Hopkins and I am also one of the Few who got the J&J Vaccine. My 1st lab results showed my antibodies at 92.6% unlike those who had the other 2 vaccines. Their results were well above the 200% and increasing each draw. This concerns me due to the fact I am Adrenal Insufficient and also just had to do a Big Blast due to a major flare. I would love to hear your thoughts about this. Thanks Dr.T

    • They are currently doing clinical trials of giving a booster J&J as well as J&J followed by an mRNA vaccine. Theoretically it makes sense that these strategies may improve responses. I hope so so that you can get another shot for better protection.

Add a Comment

Your email address will not be published. Required fields are marked *

`); } });