Vaccines might weaken with anti-inflammatory drugs
Studies suggest over-the-counter medication blocks certain enzymes.
Published Dec. 8, 2009
Over-the-counter drugs, such as aspirin and ibuprofen, might make flu vaccines less effective, a study by MU researchers found.
People who plan to take a vaccine should not take these drugs at the same time as their vaccine, said Charles Brown, an associate professor in the College of Veterinary Medicine.
"It's probably prudent that if they're not taking the drugs under a doctor's orders, they would want to avoid taking them at the time of the vaccine," Brown said.
People taking such drugs under a doctor's orders should consult their doctor, Brown said.
"We found that the most commonly used drugs in the world actually seem to reduce antibody production," said Victoria Blaho, a post-doctoral student who graduated from MU and is now enrolled at the Weill Cornell Medical College in New York.
Blaho suggested not taking anti-inflammatory drugs in the week before taking a vaccine. This allows the body to produce a full level of antibodies, which is the point of getting the vaccine in the first place, she said.
Brown and Blaho worked with Edward Dennis and Matthew Buczynski of the University of California-San Diego on the study. Brown said they spent three years testing animals, including mice, to research the project.
"We have found that animals who are either vaccinated or infected and at the same time have been treated with non-steroidal anti-inflammatory drugs — aspirin, ibuprofen, etc. — produce less antibodies," Brown said. "That implies that they're going to be less well-protected."
The over-the-counter drugs block an enzyme called COX-1, which plays an important role in immunity regulation, according to their study, which was published in the Journal of Immunology in November. Other studies have found similar results for the enzyme COX-2.
"That enzyme makes some really critical lipid molecules that are important for all sorts of things," Blaho said, citing blood pressure and kidney function as examples. "We didn't know before the study that enzymes would play a part in the immune response."
COX-1, which is secreted by most cells, might have a previously unrecognized role in the regulation of the body's response to infection, the study stated. The roles of both COX enzymes are not yet completely known.
Brown said he would like to continue this study with human subjects, perhaps within the next two years.
"Right now we have no plans to test on humans directly in the near future," Brown said. "I would like to, but that depends on getting money from the government."
He is working on a similar project studying anti-inflammatory drugs and how they affect the regulation of chronic inflammatory diseases.