Skip to main content

Dr. Roach: Blood transfusion doesn't include transfer of COVID antibodies


Dear Dr. Roach: I recently got a blood transfusion, and I’ve never had the COVID vaccine. Am I going to get those blood clots that vaccinated people got?

– Anon.

Dear Anon.: There is no evidence of risk to people receiving blood from a donor who received any COVID vaccine.

Both the Astra-Zeneca vaccine and the Janssen vaccine did have a very small number of cases of abnormal blood clots (about four cases per million recipients). The much more commonly used mRNA vaccines made by Moderna and Pfizer-BioNTech did not cause an increase in blood clotting.

When a blood transfusion is given, the red blood cells are separated from proteins, including any antibodies made by the person who received a vaccine made, so a person does not get immunity (or the possibility of side effects) from a blood transfusion from a vaccinated person. Sometimes the proteins or antibodies are given to a recipient, such as a person who has a very poor immune system, who then gains some short-lived immunity from the antibodies provided by donors. But this is not part of a regular blood transfusion (called “packed red blood cells”).

I strongly recommend getting the vaccine. COVID infection itself is much more likely to cause blood clotting problems than the vaccine ever was.

Dear Dr. Roach: I’ve been instructed by my ophthalmologist to take AREDS2 vitamins. It says on the directions to take two vitamins daily. This would be a total of 400 IU of vitamin E daily. I’ve read that vitamin E is stored by the body. Do you think that this would be too much vitamin E daily?

— D.R.

Dear D.R.: No, 400 IU of vitamin E has been proven to be safe in many clinical trials. Although vitamin E — along with vitamins A, D, and K — are fat-soluble and can be stored in the body, unlike vitamins A and D, the toxicity of vitamins E and K are very low. The AREDS and AREDS2 vitamins are given to people with the dry form of macular degeneration, and they have been shown to slow the progression of it.

Dear Dr. Roach: I just read your article on nitric oxide nasal spray. I don’t understand how it can be helpful when I’ve read that nitric oxide is a pollutant and toxic to humans and animals.

I read that it can cause eye and nose irritation, breathing difficulty and respiratory distress, as well as pulmonary edema and even death. Please tell me how the nasal spray is okay when breathing nitric oxide in the air is harmful.

— D.G.

Dear D.G.: I think you may have confused nitric oxide with nitrogen dioxide. The names are very similar, but the two chemicals are vastly different. Nitrogen dioxide is a major air pollutant that can cause the symptoms you mention.

Nitric oxide is a signaling molecule (sort of like a hormone) that has a major biological effect of relaxing smooth muscles, especially in blood vessels. That’s the effect that has researchers testing the nasal spray to see if it might be helpful in COVID infection. I do not recommend this treatment, but I am waiting for additional data.

Literally every chemical can be toxic at a high-enough dose. Nitric oxide only lasts in the body a few seconds, but a high enough exposure (such as a laboratory accident) can be immediately life-threatening. Of course, for medicinal use, the dose is small enough that there is little risk of toxicity.

Readers may email questions to ToYourGoodHealth@med.cornell.edu.