johnson and johnson april 2021 update 62bc4a0122206

Johnson and Johnson April 2021 Update

I’ve had a lot of questions over the past 2 days about vaccine safety since the CDC and FDA allowed vaccination with the Johnson and Johnson COVID 19 vaccinations to resume after a pause from April 13th to April 23rd occurred. Let’s first summarize what has occurred.

On April 13, 2021, the CDC and FDA placed a pause on vaccinations using Johnson and Johnson’s single-dose COVID 19 Vaccine. This was due to 6 occurrences of a rare type of blood clot occurrence called Central Venous Sinus Thrombosis (CVST). 6 women between the age of 18 and 49 where the CVST were closely examined. As of April 12th, more than 6.8 million doses of the Johnson and Johnson Vaccine were given in the U.S. This represents a risk of about 1 in 1 million to get this rare complication. Of interest, A study released April 14th, 2021 by Oxford University found the number of people who receive blood clots after getting vaccinated with a coronavirus vaccine are about the same for those who get Pfizer vaccines as they are for AstraZeneca. According to the study, 4 in 1 million people experience cerebral venous thrombosis after getting the Pfizer or Moderna vaccine, versus 5 in 1 million people for the AstraZeneca vaccine. Of course, rates of venous thrombosis is even higher in people who contract COVID -19 or influenza.

So there appears to be a rare risk of blood clots with both Astra-Zeneca and Johnson and Johnson vaccines and at least 1 study suggests that Pfizer/ BioNtech and Moderna may also possibly have an increased risk. These risks all appear to be just under 5 in a million and since all vaccines by nature stimulate the immune system which increases the risks of clots just by the inflammatory response is not a surprise. The specific response to the Johnson and Johnson vaccine is that platelet numbers drop which would make you think your risk of bleeding may go up but because of antibodies to platelet factor 4 and other factors are made as a rare response blood clots actually increase. Most physicians would normally treat clots with Heparin but in this instance, it makes things worse because of the antibodies and the right treatment is to actually bind the antibodies with IVIg.

As these CVST cases were rare, even much lower than using oral contraceptive pills which have an occurrence in 2.7 to 40 per 100,000 people, and the benefits of vaccination outweighed the risks the Johnson and Johnson vaccination program was resumed. Warnings to the general public and to physicians to look out for the following symptoms were made in addition to the previous warnings: Shortness of breath,

• Persistent abdominal pain,

• Severe or persistent headaches or blurred vision,

• Easy bruising or tiny blood spots under the skin beyond the site of the injection

Also, physicians were warned to evaluate anyone with clots within 2 weeks of getting a vaccination very carefully and not just give Heparin which would be contraindicated if a CVST other autoimmune type clot triggered by the vaccine could have occurred.

The information that we know to date suggests that getting a blood clot from any of the available vaccines seems to be a very rare event, likely autoimmune in origin, and the risk-benefit ratio is still favoring benefit over risk. However, there are many unanswered questions, and women on birth control, especially between the ages of 18 and 49 might consider exercising extreme caution and choose the Pfizer / BioNtech and Moderna vaccines if given a choice in vaccines but this is not a CDC or FDA recommendation and in general the CDC and FDA recommend getting any vaccine that is offered especially availability has made vaccines mostly a first come first serve operation.

If you would like to optimize your immune, brain, or gut health contact us at,, or call (925) 736-9828. Take Care, and Stay healthy.

Jeffrey Mark, M.D.







Trivia fun facts – Johnson and Johnson is headquartered in New Brunswick, US, J&J has approximately 260 operating companies in 60 countries selling products around the world. It has research facilities in more than a dozen countries and operates in about 100 manufacturing facilities in North America, Asia, Europe, and the Middle East.


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.

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