Flu Vaccines in Pregnancy

Posted by on Sep 30, 2014 in Blog | Comments Off on Flu Vaccines in Pregnancy

First do no harm, the philosophy attributed to Hippocrates, is taught to every medical student in the country. A doctor has two objectives at all times: The obvious objective is to heal, but the overruling objective, before all others, is to do no harm. All interventions carry some risk, and we often accept these risks. A patient with cancer may willingly undergo chemotherapy with full knowledge that there will be serious, even potentially life-threatening side effects.  When the risk of doing nothing is quite high, the risk of any given intervention may be justifiable. But the burden of proof of safety should be far greater for interventions designed to prevent illness, rather than treat it. Vaccinations are such an example. Vaccines are given to healthy individuals in the hope that they will provide protection against infection.  But hope is not science.  We will explore the science. In the case of flu shots given in pregnancy, there are two individuals to consider. If recommended, an influenza vaccine must be safe for both a mother and her unborn child. Many physicians and researchers question this purported safety. In the later stages of pregnancy, the growing baby occupies space normally available for a mother’s diaphragm to expand. This can lead to shortness of breath, even under normal conditions. Because of this physiological change, pregnant women who contract influenza are at greater risk of breathing difficulties and hospitalization than women who contract influenza but are not pregnant. Given this observation, the Centers for Disease Control and Prevention (CDC) recommended the administration of influenza vaccines to pregnant women in 2004.  Because a mother’s antibodies freely cross the placenta, it was thought that some degree of protection might be provided to her baby as well. The safety and efficacy of flu vaccination in pregnancy are in question, however. In a study published in the May issue of the British Medical Journal, Giuseppe Traversa and colleagues assessed maternal, fetal, and neonatal outcomes of women given the influenza A/H1N1 vaccine. The outcomes of over 86,000 pregnancies revealed that vaccinated women had significantly higher rates of gestational diabetes and eclampsia. Eclampsia is the development of seizures in a woman with severe toxemia (also known as pre-eclampsia), a condition characterized by high blood pressure and protein loss in the urine. Eclampsia is fatal in 2% of women and can result in long-term health problems in those who survive. Fetal complications, including neurological damage and death, are common. Both gestational diabetes and eclampsia are related to inflammation and immune dysregulation, making the connection to the immune stimulation of the flu vaccine very plausible. Do flu vaccines cause inflammation in pregnant women? There has been surprisingly little research in this area, but a study by Christian et al  following pregnant women given a seasonal flu vaccine found an increase in two inflammatory markers, C reactive protein (CRP) and tumor necrosis factor-alpha (TNF-a). Increases in these inflammatory compounds indicate a significant level of inflammation, which was identified during the first two days following vaccination. This increase of inflammation was confirmed in a study published in May 2014 that documented a higher level of post-vaccine immune activation in pregnant women than in non-pregnant controls receiving flu vaccines. An earlier study by Lisa Christian, Ph.D. and her colleagues found that pregnant women suffering from depression developed a more marked inflammatory response to influenza vaccines than women who did not have symptoms of depression. There is reason to be concerned about these findings. A recent study by Alan Brown, M.D. and his colleagues of over 1.2 million pregnant women found that elevations in CRP, the same...

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