Gibson: Risks from coronavirus far greater than any danger from vaccination

Earlier this week, the federal Centers for Disease Control and Prevention advised local and state governments to put administration of the Johnson and Johnson COVID-19 vaccine on hold until concerns about a rare blood-clotting side effect have have been resolved. After reviewing the available information, I would like to share a medical perspective on the issue.

To date, about 6.8 million people have received the J&J vaccine in the United States. It is the only one-shot vaccine available here.

Of those, six women between the ages of 18 and 48 have developed cerebral sinus venous thrombosis, known as CSVT. It causes a potentially fatal blood clot to form in the veins that drain blood from the brain and send it on to the heart. And it did prove fatal for one of the six.

CSVT is not an unknown condition. It occurs in roughly three to five people per one million every year.

That means that every three months, about one person out of every million would form a clot in the cerebral sinus system. The J&J vaccine, however, was approved on February 28 and not distributed for use until early March, just over a month ago.

In one month, we would expect one cerebral sinus blood clot for every three million people. The rate here is more than twice that.

What is perhaps of more interest is that all of the clots were associated with a drop in the number of platelets in the blood — tiny cell fragments that help us form a clot at the earliest stages of a cut or other bleeding injury.

Because of the higher than expected CSVT rate, and the associated drop in platelets, the CDC wisely decided to declare a pause so the matter could be investigated further.

This is similar to the action taken in Europe in March over similar concerns about the Astra Zeneca vaccine. It was triggered by a March 15 report from the Paul-Ehrlich Institute in Germany identifying seven cases of CSVT out of 1.6 million people vaccinated.

Both the Astra Zeneca and J&J vaccines employ chimpanzee adenoviruses, harmless to humans, to get the blueprint for the coronavirus spike protein into our cells. It is unknown if this commonality is related to the increased incidence of clots.

Researchers believe the clots are being caused by the immune system of affected patients being triggered to form antibodies against the platelets in their blood. This makes the platelets clump together and form clots in the blood vessels.

I have seen this rare form of clotting before. When I was in medical school, a man was admitted to our hospital with a blood clot in his leg.

He was given heparin, the standard anti-coagulant, to prevent further clotting. But within days, he developed clots throughout his body. His platelet count plummeted in tandem, as platelet clots formed in his arteries and veins.

He died shortly thereafter. His was one of the earliest recognized cases of heparin-induced thrombocytopenia.

The condition seen with the vaccine patients appears similar. Some researchers are calling it vaccine-induced thrombotic thrombocytopenia, or VITT.

Why it has been seen in the Astra Zeneca and J&J vaccines so far is unknown. It may still be possible that this could occur with the Moderna and Pfizer vaccines, but the absence of such reports so far is certainly reassuring.

It may also be that the risk of this reaction is limited to younger people.

We know that auto-immune disorders generally appear at younger ages, unlike many diseases that become more common as we get older, like cancers and heart disease. The immune system of younger people may be more prone to being triggered to create this exceedingly rare reaction. Accordingly, we might see recommendations that the J&J vaccine be used only in the older population.

The fact that all of the vaccine-associated CVST cases in the U.S. have arisen among women is also of interest.

Curiously, blood clots in the cerebral sinus not associated with vaccines occur in women 75 percent of the time, and usually in 20- to 40-year-olds. That has been suggested, but not proven, to stem from use of birth control pills by women of childbearing age.

Whether some common cause makes women more prone to vaccine-associated clots is not clear. We are only at the leading edge of learning about this condition.

It is also vital to note that COVID-19 itself triggers clotting at an astonishingly high rate. More than 30% of critically ill COVID patients, and 58% of patients succumbing to COVID, suffer from clotting.

An emergency department study of patients admitted with COVID pneumonia shows 18% of those undergoing chest CT scans suffered from clotting in the lungs. I cannot think of another infectious disease that promotes blood clots at such an extraordinary rate.

If you are frightened of blood clots, the thing you should most want to avoid is the disease, not the vaccine.

The risk of a clot from the vaccine appears to be around one in one million. The risk of clots if you catch COVID is probably close to 1,000 times that, so the best way to avoid dangerous blood clots is getting vaccinated.

No vaccine is completely free of risks. But even if these preliminary findings are confirmed, the vaccine is still extraordinarily safe. The risks from contracting COVID-19 far outweigh the minute risks from vaccination with J&J or Astra Zeneca.

Dr. Scott Gibson is board-certified in internal medicine. He owns and operates clinical and surgical facilities in McMinnville.


Bill B

Sure glad that this guy is not my doctor! Is he really saying that the vaccination did not initiate the clot?


No, he is not saying that. He is saying that while the Johnson & Johnson vaccine apparently triggers clotting in roughly one out of every million recipients, the disease itself causes clotting at a vastly greater rate. So the best way to protect yourself against clotting is to get vaccinated.

As Dr. Gibson put it:

If you are frightened of blood clots, the thing you should most want to avoid is the disease, not the vaccine.

"The risk of a clot from the vaccine appears to be around one in one million. The risk of clots if you catch COVID is probably close to 1,000 times that, so the best way to avoid dangerous blood clots is getting vaccinated."


Bill B

I certainly agree with the importance of getting vaccinated. But not with Johnson & Johnson or AstraZeneca. The jury is still out on the MRNA vaccines. The best choice is coming up in the next week or so and that is novavax.

Bill B

Reading more on the JNJ vaccine and clots. Actually only 1 miilion doses were given to females ages 18-49. That puts the ratio at 1 clot case per 150,000. That's a big number in my mind and shows how the media and this writer can distort the picture.

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