Aspirin and Tylenol May Decrease the Effectiveness
of Flu, Other Vaccines
Best choice maybe to not take aspirin, Tylenol or
ibuprofen for a couple weeks before and after you get a vaccine
Dec. 1, 2009 - With flu season in full swing and
the threat of H1N1 looming, demand for vaccines is at an all-time high.
Although those vaccines are expected to be effective, University of
Missouri researchers have found further evidence that some
over-the-counter drugs, such as aspirin and Tylenol, that inhibit
certain enzymes could impact the effectiveness of vaccines.
“If you’re taking aspirin regularly, which many
people do for cardiovascular treatment, or acetaminophen (Tylenol) for
pain and fever and get a flu shot, there is a good chance that you won’t
have a good antibody response,” said Charles Brown, associate professor
of veterinary pathobiology in the MU College of Veterinary Medicine.
Limited access to health care, inadequate testing
may contribute to higher rates of mortality and lower rates of
diagnosis of flu in elderly with dementia
“These drugs block the enzyme COX-1, which works in
tissues throughout the body. We have found that if you block COX-1, you
might be decreasing the amount of antibodies your body is producing, and
you need high amounts of antibodies to be protected.”
COX enzymes play important roles in the regulation
of the immune system. The role of these enzymes is not yet understood
completely, and medications that inhibit them may have adverse side
effects. Recent research has discovered that drugs that inhibit COX
enzymes, such as COX-2, have an impact on the effectiveness of vaccines.
Brown’s research indicates that inhibiting COX-1,
which is present in tissues throughout the body, such as the brain or
kidneys, could also impact vaccines’ effectiveness.
These MU researchers also are studying the
regulation of inflammation and how that leads to the development or
prevention of disease. Many diseases, such as arthritis, cardiovascular
disease and diabetes, are all chronic inflammatory diseases.
Contrary to
previous beliefs, inflammation is generally a good thing that helps
protect individuals from infection. Many of the non-steroidal drugs that
treat inflammatory conditions reduce antibody responses, which are
necessary for treating infections.
“So far, we’ve tested this on an animal model and
have found that these non-steroidal drugs do inhibit vaccines, but the
next step is to test it on humans,” Brown said.
“If our results show that COX-1 inhibitors affect
vaccines, the takeaway might be to not take drugs, such as aspirin,
Tylenol and ibuprofen, for a couple weeks before and after you get a
vaccine.”
Brown’s research, “Cycloozygenase-1 Orchestrates
Germinal Center Formation and Antibody Class-Switch via Regulation of
IL-17,” has been published in The Journal of Immunology.
Dec. 1, 2009 - With flu season in full swing and
the threat of H1N1 looming, demand for vaccines is at an all-time high.
Although those vaccines are expected to be effective, University of
Missouri researchers have found further evidence that some
over-the-counter drugs, such as aspirin and Tylenol, that inhibit
certain enzymes could impact the effectiveness of vaccines.
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