Painkillers may Threaten Power of Vaccines

Vaccines and painkillers do not
match; © NCI Visuals Online

The research has widespread implications: study authors report that an estimated 50 to 70 percent of Americans use nonsteroidal anti-inflammatory drugs (NSAIDs) for relief from pain and inflammation, even though NSAIDs blunt the body’s natural response to infection and may prolong it.

“For years we have known that elderly people are poor responders to the influenza vaccine and vaccines in general,” said principal investigator Richard P. Phipps, Ph.D., a professor of Environmental Medicine, and of Microbiology and Immunology, Oncology and Pediatrics. “And we also know that elderly people tend to be heavy users of inhibitors of cyclooxygenase such as aspirin. This study could help explain the immune response problem.”

When a person is vaccinated, the goal is to produce as many antibodies as possible to effectively neutralize the infection. To do this, white blood cells called B-lymphocytes, or B cells, spring into action to produce those antibodies. B cells also serve as the immune system’s memory for future protection against the illness.

But Phipps and colleagues discovered that human B cells also highly express the cyclooxygenase-2 (cox-2) enzyme, which is not intrinsically bad unless it is overproduced, causing pain and fever. So, when a person takes a drug to block the cox-2 enzyme – and thereby reduce pain and fever – the drug also reduces the ability of B cells to make antibodies.

“The next step is to figure out the worst time to take drugs that inhibit cox-2 in the context of getting vaccinated. Is it the day before, the day of, or the day after. The timing is likely to be very important,” Phipps said. “But meanwhile, we believe that when you reach for the medicine cabinet to reduce pain at the injection site, that is probably the wrong thing to do.”; Source: University of Rochester Medical Center