The scientific studies on the flu vaccine are quite convincing. The influenza vaccine is 70-90% effective in preventing the flu in young, healthy adults.1 It can even reduce influenza-related death in the elderly by as much as 80%.2-3 In addition, the flu shot has been demonstrated to significantly reduce the risk of an influenza outbreak in nursing homes. 4 Now, a growing body of evidence indicates that regular flu shots can reduce the risk of heart attack and stroke better then even cholesterol-lowering drugs!
In December of 2000, Naghavi and others5 reported the results of a small study they did on coronary heart disease patients seen in a single hospital during the flu season. In their study, patients who did not received the flu shot that season were three times as likely to develop a new heart attack than those who did receive the flu shot. Of course, the study was small, so further research was suggested.
Now that research has been done. In April of 2002, the results of a placebo-controlled study6 of 301 heart attack and angioplasty/stent patients was released. In this study, patients were given either the flu vaccine or a placebo. A follow-up interview was performed in six months. Those who received the placebo were slightly more than twice as likely to have a heart attack within those six months than those who received the flu vaccine. Thus, the flu vaccine protects not only against the flu, but also against heart attacks! In fact, the results indicate that the incredibly inexpensive flu shot could end up saving more lives than expensive cholesterol-lowering drugs.
Not only does the flu shot protect against heart attacks, it also seems to protect against stroke. Lavelle and others report on a study7 of 270 patients that found the risk of stroke is roughly twice as great for those who do not get the flu shot as compared to those who do. Once again, this is a small study and needs to be supported by further research. Nevertheless, the data are encouraging.
This research also adds to a growing body of research which shows that some vaccines protect against more than just the disease for which they were designed. Not only does the flu shot reduce the risk of heart attacks and possibly strokes, the DPT vaccine protects against SIDS, and following the standard vaccination schedule reduces the risk of general infection. This, of course, is not surprising, as the data clearly show that the higher the vaccination rate in a population, the more healthy the population.
1. Palache AM, “Influenza vaccines: a reappraisal of their use.”, Drugs 54:841-56, 1997. Return to Text
2. Arden NH, Patriarca PA, Kendal AP, “Experiences in the use and efficacy of inactivated influenza vaccine in nursing homes. “, In: Kendal AP, Patriarca PA, eds. Options for the control of influenza., New York, NY: Alan R. Liss, Inc., 155-68, 1986.
3. Patriarca PA, et al., “Efficacy of influenza vaccine in nursing homes: reduction in illness and complications during an influenza A (H3N2) epidemic.”, JAMA 253:1136-9, 1985
4. Patriarca PA, et al., “Risk factors for outbreaks of influenza in nursing homes: a case-control study. ” Am J Epidemiol 24:114-9, 1986
5. Naghavi M, et al., “Association of influenza vaccination and reduced risk of recurrent myocardial infarction.” Circulation 102:3039-3045, 2000
6. Gurfinkel EP, et al. “Influenza vaccine pilot study in acute coronary syndromes and planned percutaneous coronary interventions: The FLU Vaccination Acute Coronary Syndrome (FLUVACS) Study.” Circulation 105:2143-2147, 2002
7. Lavallee P, et al., “Association between influenza vaccination and reduced risk of brain infarction.” Stroke 33:513-518, 2002
Dr. Wile is not a medical doctor. He is a nuclear chemist. As a result, Dr. Wile not dispense medical advice. He simply educates the public about scientific issues. Please consult a board-certified medical doctor before making any medical decisions for yourself or your family.