With the exception of vitamins and minerals, EFSA has positively evaluated more health claims for the two fatty acids EPA and DHA than for any other substance. Thanks to a vast body of scientific evidence, there are approved health claims relating to heart function, the maintenance of normal vision, normal brain function, blood pressure, blood lipids (triglyceride levels) and brain and eye development in the foetus.
Meanwhile, supplementation with omega-3 fatty acids, alongside vitamins, minerals and other micronutrients has been described as “a safe, effective, and low-cost strategy to help support optimal immune function” and they are one of the top five preparations for the immune system. One reason for this is that the body of evidence on the role of EPA and DHA in immune health continues to grow. In 2020, for example, scientists found new evidence of the way they provide basic building blocks to reduce inflammation.
The structure of the immune system
The immune system is made up of a multitude of organs, cells and messenger substances, and in order for the body to respond adequately to pathogens such as bacteria, viruses and fungi, they all have to work together. Two of the most important components of the immune system are the skin and the mucous membranes. These are the first point of entry for many pathogens and the place where the first defence reactions occur. The lymph nodes and ducts, as well as the palatine and pharyngeal tonsils, contain defence cells which, in turn, produce antibodies. They represent the basic framework of the immune response. The defence cells, T cells or T lymphocytes, are formed in the thymus gland and stored in the spleen, the largest lymph organ, until they are used. Meanwhile, the bone marrow is where B lymphocytes are formed (the "B" stands for bone marrow.) 
New study: Omega-3 fatty acids and the immune system
In 2020, Professor Dr Oliver Werz from Friedrich Schiller University and Professor Dr Charles N. Serhan from Harvard Medical School reported on the connection between omega-3 fatty acids and immune function. Pathogenic bacteria influence the function of macrophages and thus control the entire process of inflammation, and fatty acids play a role in the dissolution of this cascade. Werz and Serhan reported on the exact underlying cellular mechanism for this process. Using pathogens such as Escherichia coli and Staphylococcus aureus, they found that the bacteria produced opposite effects in different macrophage populations, with the different populations playing a role in either the initial or the resolution phase of inflammation. However, the bacteria also cause macrophages to produce more inflammation-dissolving substances such as resolvins, lipoxins and protectins from omega-3 fatty acids. Resolvins have a lipid structure and are derived from EPA and DHA.
The study may be important for the treatment of chronic inflammatory diseases in the future.4 Its findings are also consistent with those of a review by S. Gutiérrez from Sweden, which found that EPA and DHA provide the basic building blocks for inflammation-resolving substances that promote the subsiding of inflammatory reactions.
COVID-19 and Omega-3 nutrition
Naturally, recent studies have investigated a possible role for omega-3s in the battle against COVID-19. Research from Cedars-Sinai Medical Center in Los Angeles suggests that people with a high omega-3 Index are less likely to die from a COVID-19 infection. The mechanisms of action for this are thought to be the anti-inflammatory effects of EPA and DHA, which result in a lower cytokine response and faster resolution of inflammation. Based on this information, numerous intervention studies with EPA and DHA on the prevention and treatment of COVID-19 have begun to take place.
Furthermore, diet is likely to play an important role in the course of COVID-19. Depending on the severity of the viral illness, it is important to continue to provide the body with important micronutrients, including omega-3 fatty acids. Research by Mendivil has made clear that omega-3 fatty acids lead to a regulated immune response.  Since severe courses of COVID-19 are more frequently observed in patients with cardiovascular diseases such as high blood pressure and narrowing of the coronary arteries, supplementation with omega-3 fatty acids may also be beneficial here.
High concentration, high-quality
A variety of factors affect the anti-inflammatory properties of EPA and DHA. For example, higher concentrations of EPA and DHA give better results than lower concentrations. Epax, a manufacturer of premium-quality marine omega-3 concentrates, has been a partner of Goerlich Pharma GmbH since 2007. It was the first company to create condition-specific EPA/DHA ingredients backed by clinical studies, and its recent investment in R&D has allowed it to develop new products and state-of-the art technologies. Its proprietary distillation process, for example, allows it to deliver even higher levels of EPA/DHA concentration.
Christina Spötzl is the project development manager at Goerlich Pharma GmbH, a specialised contract manufacturer and developer for food supplements and foods for special medical purposes. It is the exclusive distribution partner for Epax® omega-3 concentrates and offers vegan algae oils in Germany, Austria and Switzerland and offers a wide range of products with 'Epax® or vegan omega-3 inside.' The safety and efficacy of Epax products have been tested in over 100 peer-reviewed clinical studies―more than any other marine omega-3 company. This body of research covers a wide range of categories, including immunity, as well as cardiovascular health, joint health and cognition.
 Bundesministerium für Ernährung und Landwirtschaft (2019): „Nährwert- und gesundheitsbezogene Angaben bei Lebensmitteln – die Health Claims Verordnung“: URL: https://www.bmel.de/DE/themen/ernaehrung/lebensmittel-kennzeichnung/pflichtangaben/naehrwertinformationen-health-claims.html (Stand: 09.02.2021)
 P. Calder et al. (2020): “Optimal Nutritional Status for a Well-Functioning Immune System Is an Important Factor to Protect against Viral Infections“
 Euromonitor International (2020): Euromonitor International Health & Nutrition Survey 2020
 O. Werz et. al (2020): “ Human macrophages differentially produce specific resolvin or leukotriene signals that depend on bacterial pathogenicity”
 Apothekenumschau (2019): „Das Immunsystem“ URL: https://www.apotheken-umschau.de/Immunsystem (Stand: 09.02.2021)
 S. Gutiérrez et al. (2019): “Effects of Omega-3 Fatty Acids on Immune Cells”
 Fatty Acid Research Institute (2021) ‘Pilot Study Suggests Link Between the Omega-3 Index and Risk for Death from COVID-19’
 P. Weill et al. (2020): „May omega-3 fatty acid dietary supplementation help reduce severe complications in Covid-19 patients?"
 C.O. Mendivil (2021): „Dietary Fish, Fish Nutrients and Immune Function: A Review"
 Gesund.bund.de (2021): „COVID-19: die Erkrankung in der Übersicht“ URL: https://gesund.bund.de/covid-19?pk_campaign=ghp (Stand: 09.02.2021)
 K. Khoramipour (2020): „Physical activity and nutrition guidelines to help with the fight against Covid-19"