Pain Killers Adversely Inhibit Vaccination Benefits

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622804The questions concerning the benefits Vs risks of vaccination in light of the recent global approach to H1N1 (novel influenza) vaccine recommendations has thrown this area of medicine under a very bright spotlight. Leaving aside the question ‘to vaccinate or not’ a recent article has raised a simple and useful question. If I take a non steroidal pain killer (NSAID’s) to reduce post vaccine discomfort, or are ingesting them for other reasons does it affect my vaccine promoted immune response?

The answer it appears is yes. Advil, Tylenol, Neurofen and Aspirin – at the time of injection may blunt the effect of the vaccine and have a negative effect on the immune system.

We have studied this question using virus particles, live virus, and different kinds of pain relievers, in human blood samples and in mice — and all of our research shows that pain relievers interfere with the effect of the vaccine. Says Richard P. Phipps, Ph.D

The effect of NSAID’s is to reduce the production of antibodies. The desired effect of vaccination is to promote an adaptive immune response from relevant B cells including the memory potentiated antibodies designed to recognise a future immune transgression and motivate defences.

A paper in the Lancet earlier this year found that children were also compromised by the use of acetaminophen (paracetamol)  used to manage fever post vaccination (This is not a NSAID). The interpretation of these studies which looked at 459 healthy infants[1] was:

Although febrile reactions significantly decreased, prophylactic administration of antipyretic drugs at the time of vaccination should not be routinely recommended since antibody responses to several vaccine antigens were reduced.

NSAIDs act in part by blocking the cyclooxygenase-2 (cox-2) enzyme. Blocking the cox-2 enzyme is not a good idea in the context of vaccination, however, because the cox-2 enzyme is necessary for the optimal production of B-lymphocytes (B-Cells).[2]

Therefore, when a person takes a medication to reduce pain and fever, he or she might also inadvertently reduce the ability of B cells to make antibodies.

In addition to exposure, timing also plays an important role in the detrimental effects. In a study published in Cellular Immunology in 2009, the study group noted that treatment during the early part of the first stages of inflammation or fever would have the greatest detrimental effect on the antibody production.[3]

NSAIDs are one of the most commonly used drugs; they are recommended for all age categories, are prescribed for relieving transient pain or in cases of serious inflammatory diseases. By decreasing antibody synthesis, NSAIDs also have the ability to weaken the immune system which can have serious consequences for children, the elderly and the immune-compromised patients.


The take home message here is that, if you decide to vaccinate and suffer post vaccination fever, other methods of fever reduction and pain management than the use of NSAID’s or antipyretics such as paracetemol are to be recommended, otherwise the ‘benefits’ from the induction of memory B cells post stimulation will be diminished, and may even be rendered ineffective.

An internal inflammatory response to vaccination is not uncommon – it’s an essential part of the process the immune system initiates to prepare for a successful fight against an actual infection. But it’s also expected to be a weak and brief response.

Inflammatory responses to vaccination typically do no harm, are mild, and typically go away within a few days.


[1] Prymula R, Siegrist CA, Chlibek R, Zemlickova H, Vackova M, Smetana J, Lommel P,  Kaliskova E, Borys D%

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  • very useful article – presumably although acetaminophen is not an NSAID, it works along similar pathways of reducing ability of B cells to make antibodies? any alternatives one could recommend to parents with feverish children – apart from sponging down?

    • Dear Martina
      You are correct, acetaminophen is an antipyretic, used for manging the fever post vaccination, but it also impacts on the antibody development although it appears the mechanisms involved in this are yet to be explained.
      The body’s normal body temperature is approximately 98.6 degrees Fahrenheit (37. 0ºC) and a fever is medically defined as a rectal temperature greater than 100.4ºF or 38.0ºC. Non drug therapies used to control fever include:
      Using cold wet sheets to cover the body and reduce temperature
      Using cold water sponges
      Drinking adequate cold fluids, including small quantities of electrolytes
      Some herbs are proposed to reduce fever as well (Yarrow and Meadowsweet)
      As this is post vaccination fever as opposed to pathogen or unknown induced fever, it should have a naturally reduced period before resolving.

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