What do Enterovirus D68, Ebola and Influenza have in common? The answer is that they are all viruses, and they have all been in the news over the past year. This article will provide a brief discussion of these viruses, and what we can do to strengthen our immune systems—arguably the most effective approach that can be taken in protecting ourselves against these and other viruses once exposed to them.

Enterovirus D68 (EV-D68) is one of more than 100 non-polio enteroviruses. EV-D68 can cause mild to severe respiratory illness. Mild symptoms may include fever, runny nose, sneezing, cough, and body and muscle aches. Severe symptoms may include wheezing and difficulty breathing. Anyone with respiratory illness should contact their doctor if they are having difficulty breathing or if their symptoms are getting worse.1

Since EV-D68 causes respiratory illness, the virus can be found in an infected person’s respiratory secretions, such as saliva, nasal mucus, or sputum. EV-D68 likely spreads from person to person when an infected person coughs, sneezes, or touches a surface that is then touched by others. In the United States, people are more likely to get infected with enteroviruses in the summer and fall. Cases are likely to decline later in the fall.2

Ebola, previously known as Ebola hemorrhagic fever, is a rare and deadly disease caused by infection with one of the Ebola virus strains. Ebola is caused by infection with a virus of the family Filoviridae, genus Ebolavirus. Ebola was first discovered in 1976 near the Ebola River in what is now the Democratic Republic of the Congo. Since then, outbreaks have appeared sporadically in Africa.3

The best way to prevent exposure to Ebola is to avoid travel to an area affected by the 2014 Ebola outbreak. CDC has issued a Warning, Level 3 travel notice for U.S. citizens to avoid nonessential travel to Guinea, Liberia, and Sierra Leone. CDC has downgraded the travel notice for Nigeria to a Watch, Level 1 because of the decreased risk of Ebola in Nigeria. A level 2 travel notice was also issued for the Democratic Republic of the Congo (DRC). If you must travel to those areas, wash your hands frequently or use an alcohol-based hand sanitizer. Also, avoid contact with blood and body fluids of any person, particularly someone who is sick. Seek medical care immediately if you develop fever (temperature of 101.5°F/ 38.6°C) and any of the other following symptoms: headache, muscle pain, diarrhea, vomiting, stomach pain, or unexplained bruising or bleeding.4

Influenza (“the flu”) is an infectious disease caused by RNA viruses of the family Orthomyxoviridae, the influenza viruses. The most common symptoms are chills, fever, runny nose, sore throat, muscle pains, headache (often severe), coughing, weakness/fatigue and general discomfort. Although it is often confused with other influenza-like illnesses, especially the common cold, influenza is a more severe disease.5 Influenza may produce nausea and vomiting, particularly in children, but these symptoms are more common in the unrelated gastroenteritis, which is sometimes inaccurately referred to as “stomach flu” or “24-hour flu.”6 Typically, influenza is transmitted through the air by coughs or sneezes containing the virus. Influenza can also be transmitted by direct contact with bird droppings or nasal secretions, or through contact with contaminated surfaces.

Vitamin A helps regulate the immune system, which helps prevent or fight off infections by making white blood cells that destroy harmful bacteria and viruses.7,8,9,10,11,12 The skin and mucosal cells (cells that line the eyes and the respiratory, urinary, and intestinal tract) function as a barrier and form the body's first line of defense against infection. When those linings break down, it becomes easier for bacteria to enter the body and cause infection. Vitamin A promotes healthy surface linings of the eyes and the respiratory, urinary, and intestinal tracts,13 helping the skin and mucous membranes function as a barrier to bacteria and viruses.14,15,16 In addition vitamin A plays a central role in the development and differentiation of white blood cells, such as lymphocytes, which play critical roles in the immune response by fighting infections.17

Vitamin C also plays a profound role in the health of the immune system, stimulating the production and function of white blood cells, including leukocytes, neutrophils, lymphocytes and phagocytes.18,19,20,21,22,23,24 In addition, research has demonstrated that supplemental vitamin C increases serum levels of antibodies25,26 and C1q complement proteins.27,28,29 Also, Vitamin C has been shown to increase interferon levels in-vitro,30 and research on supplemental vitamin C and the common cold suggests that it promotes an antiviral effect in humans.31 In a study involving 252 adult subjects with a cold or flu who were treated with hourly doses of 1000 mg of vitamin C for the first six hours, and then three times daily thereafter. A control group of 463 subjects were treated with pain relievers and decongestants. The results were that overall reported flu and cold symptoms in the vitamin C group decreased 85 percent compared with the control group after the administration of megadose Vitamin C. The researchers in this study concluded, “Vitamin C in megadoses administered before or after the appearance of cold and flu symptoms relieved and prevented the symptoms in the test population compared with the control group.”32

Vitamin E is an antioxidant that protects the integrity of cell membranes from damage caused by free radicals.33 In particular, the alpha-tocopherol form of vitamin E protects against peroxidation of polyunsaturated fatty acids, which can potentially cause cellular damage and subsequently lead to improper immune responses.34 Several studies in animal models as well as humans indicate that vitamin E deficiency impairs both humoral and cell-mediated aspects of adaptive immunity, including B and T cell function.35 Moreover, vitamin E supplementation in excess of current intake recommendations has been shown to enhance immunity and decrease susceptibility to certain infections, especially in elderly individuals. In fact, a randomized, placebo-controlled trial in elderly nursing home residents reported that daily supplementation with 200 IU of synthetic alpha-tocopherol (equivalent to 90 mg of RRR-alpha-tocopherol) for one year significantly lowered the risk of contracting upper respiratory tract infections, especially the common cold, but had no effect on lower respiratory tract (lung) infections.36

Zinc is essential for the integrity of the immune system, and inadequate zinc intake has many adverse effects.37 The immunologic mechanisms whereby zinc modulates increased susceptibility to infection have been studied for several decades. It is clear that zinc affects multiple aspects of the immune system, from the barrier of the skin to gene regulation within lymphocytes. Zinc is crucial for normal development and function of cells mediating nonspecific immunity such as neutrophils and natural killer cells. Zinc deficiency also affects development of adaptive immunity.38 Furthermore, in both young adults and elderly subjects, zinc supplementation decreased oxidative stress markers and generation of inflammatory cytokines.39 According to the U.S. Department of Agriculture, 12 percent of the U.S. population does not meet the estimated average requirement for zinc.40

Propolis is a resinous substance collected from various plants by bees. It is used in the construction of, and to seal the cracks in, the beehive. It is a mixture of resin, essential oils and waxes, and also contains amino acids, minerals, ethanol, vitamin A, B complex, E, and flavonoids.41 In addition to its construction adhesive application, propolis also has antimicrobial properties, which helps to prevent microorganisms from entering the hive and causing illness. In human clinical research, supplementation with propolis has been shown to help effectively treat viral upper respiratory tract infections (e.g. colds and flu).42,43,44

Garlic has an extensive history of use against a variety of pathogens that cause infections.45,46 In in-vitro research, the antiviral activity of garlic was tested on human cytomegalovirus (HCMV). In this research, garlic was effective when administered concurrently with the HCMV, but the effect was stronger when pretreatment with garlic occurred. The authors of this study recommended that clinical use of garlic against HCMV infection should be persistent, and the prophylactic (preventive) use of garlic is preferable in immunocompromised patients.47 In other in-vitro research, garlic and its sulfur compounds were tested against selected viruses, including herpes simplex virus type 1, herpes simplex virus type 2, parainfluenza virus type 3, vaccinia virus, vesicular stomatitis virus, and human rhinovirus type 2. The sulfur compounds were found to effect antiviral activity.48

Arguably, Echinacea is the granddaddy of all immune-enhancing herbs. It is excellent in helping to prevent and treat colds and influenza. Research reveals that Echinacea supports the immune system by activating white blood cells (lymphocytes and macrophages).49 Echinaceaalso increases the production of interferon, an immune component, which is important in responding to viral infections.50

Several double-blind, clinical studies have confirmed Echinacea's effectiveness in treating colds and flu.51,52,53,54 However, some research suggests that Echinacea may be more effective if used at the onset of these conditions.55,56 One study involving 238 subjects confirmed that Echinacea was safe and effective in producing a rapid improvement of cold symptoms. In the subgroup of patients who started therapy at an early phase of their cold, the effectiveness of Echinacea was most prominent.57 In a similar study, 246 subjects with a cold were treated withEchinacea preparations or a placebo.

Those treated with the Echinaceapreparations experienced a reduction of symptoms, significantly more effective than the placebo. The researchers concluded that the Echinacea preparations, “represent a low risk and effective alternative to the standard symptomatic medicines in the acute treatment of common cold.”58

Edible mushroom extracts, especially those used in Chinese and Japanese natural medicines (Shiitake, Maitake, Reishi), are a rich source of naturally occurring polysaccharides, especially beta glucans. These polysaccharides in the aforementioned mushrooms can directly stimulate immune reactions by primarily modulating immune responsive cytokines such as IL-1, IL-2, IL-6 and INF-gamma.59,60,61 Complex polysaccharides found in these mushrooms act as immunomodulators, helping to support immune system function. These polysaccharides, among the most powerful studied,62 are well absorbed when taken orally and have been used as a potential tool for viral infections.63,64

Astragalus is primarily used for its immune stimulating and adaptogenic properties.65,66 The Chinese use it as a classic energy tonic, often in place of Ginseng for people under 40 years of age. Astragalus works by stimulating several factors of the immune system. Evidence based uses of Astragalus include the treatment of infections (including common cold, flu, herpes, HIV), water retention, hypertension, antioxidant, anti-inflammatory, and cardiac output.67,68,69

The nutraceuticals discussed in this article are not the only ones that can help promote a strong, healthy immune response, but they are a good start. You can use some or all of them.


  1. Enterovirus D68. Centers for Disease Control and Prevention National Center for Immunization and Respiratory Diseases, Division of Viral Diseases. Page last reviewed: September 25, 2014. Page last updated: October 10, 2014. Retrieved October 11, 2014 from http://www.cdc.gov/non-polio-enterovirus/about/ev-d68.html.
  2. Enterovirus D68. Centers for Disease Control and Prevention National Center for Immunization and Respiratory Diseases, Division of Viral Diseases. Page last reviewed: September 25, 2014. Page last updated: October 10, 2014. Retrieved October 11, 2014 from http://www.cdc.gov/non-polio-enterovirus/about/ev-d68.html.
  3. About Ebola Virus Disease. Centers for Disease Control and Prevention, National Center for Emerging and Zoonotic Infectious Diseases, Division of High-Consequence Pathogens and Pathology, Viral Special Pathogens Branch. Page last reviewed: October 3, 2014. Page last updated: October 3, 2014. Retrieved October 11, 2014 from http://www.cdc.gov/vhf/ebola/about.html.
  4. Questions and Answers on Ebola. Centers for Disease Control and Prevention, National Center for Emerging and Zoonotic Infectious Diseases, Division of High-Consequence Pathogens and Pathology, Viral Special Pathogens Branch. Page last reviewed: October 8, 2014. Page last updated: October 8, 2014. Retrieved October 11, 2014 from http://www.cdc.gov/vhf/ebola/outbreaks/2014-westafrica/qa.html.
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Gene Bruno, MS, MHS

Gene Bruno is the Dean of Academics and Professor of Dietary Supplement Science for Huntington College of Health Sciences (a nationally accredited distance learning college offering diplomas and degrees in nutrition and other health science related subjects. Gene has two undergraduate Diplomas in Nutrition, a Bachelor’s in Nutrition, a Master’s in Nutrition, a Graduate Diploma in Herbal Medicine, and a Master’s in Herbal Medicine. As a 32 year veteran of the Dietary Supplement industry, Gene has educated and trained natural product retailers and health care professionals, has researched and formulated natural products for dozens of dietary supplement companies, and has written articles on nutrition, herbal medicine, nutraceuticals and integrative health issues for trade, consumer magazines, and peer-reviewed publications. Gene's latest book, A Guide to Complimentary Treatments for Diabetes, is available on Amazon.com, and other fine retailers.