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Long-term prevention of COVID-19

A while ago we informed you on our website about the possibilities of prevention against Covid-19. With regard to the fact that knowledge about this disease is still developing, together with Dr. Roman Košek we again focused on the coronavirus and on new observations concerning preventive measures for the highest risk groups. If the Czech Republic is hit by an expected second wave of the epidemic, it will be useful to be prepared...

Until recently, the SARS-CoV-2 virus and the associated Covid-19 illness represented a great unknown. What has changed in this respect in the last few weeks?
Intensive research is currently under way worldwide relating to the SARS-CoV-2 virus, as well as clinical trials focusing on the prevention and treatment of the Covid-19 illness. This can be seen in the amount of articles, not only in professional journals, which are growing at an exponential rate. For example, more than 1,900 new articles were published in the last week of May alone. However, interest in this burning issue and eagerness to publish quickly can mean a higher risk of producing articles of variable quality. The results of large clinical trials conducted under standard conditions are not yet available. As a result, opinions on recommended treatment and prevention may change further in the future, depending on the level of knowledge we have attained. The State Institute for Drug Control (SIDC) in the Czech Republic is continuously monitoring publications in the professional literature and providing information on the current state of research into pharmaceutical substances or preparations, which are undergoing evaluation of their safety and efficacy for the treatment of Covid-19. At present, 545 clinical evaluations from around the whole world are being monitored in the SIDC database, of which more than 50 of the most promising pharmaceutical preparations are being evaluated. At the forefront of especial interest are four possibilities of treatment, which are also being sponsored by the World Health Organization (WHO). These are remdesivir, chloroquine/hydroxychloroquine, lopinavir/ritonavir, and lopinavir/ritonavir in combination with interferon beta. So far all of these concern only experimental treatment. None of them have yet been officially approved (registered) for the treatment of Covid-19. 

Can you remind us which groups of people are among the most at risk from the virus SARS-CoV-2?
From the available information it ensues that Covid-19 is most often a threat to men aged over 65 years. Also at high risk are people of both sexes who suffer from obesity, hypertension (76.1 %), diabetes (35.5 %), ischemic heart disease (33 %) or ventricular fibrillation of the heart (24.5 %), those with an oncological diagnosis (20.3 %), chronic disorder of the kidneys (18 %) or obstructive disorder of the respiratory tracts (13.2%), and also in a lower percentage people with dementia (6.8 %). At the same time it applies that the risk posed by Covid-19 is increased by polymorbidity, namely the occurrence of more than one chronic disease simultaneously. Two risk diagnoses increase the risk of the illness by 25.6%, three or more diagnoses by 48.5%. 

What are the current general recommendations for prevention of Covid-19? 
Of fundamental importance is regular consumption of anti-inflammatory foods, namely fruit, vegetables, fibre and probiotics, together with reduced consumption of meat, saturated fats and highly processed food containing an excess of sugar and salt. Aerobic physical activity is highly beneficial, low intensity exercise is sufficient, but should be regular. In addition it’s recommended to reduce stress, ensure enough sleep and to maintain social contacts. With regard to the above-mentioned risk factors, the basis of prevention is good compensation of chronic diseases, and naturally also abiding by all the anti-epidemic measures. It’s assumed that an infected person is already contagious 1-3 days before the manifestation of the first symptoms, and that as many as half of cases of the illness may be related to transmission from asymptomatic or pre-symptomatic individuals. 

Are there any specific preventive measures for the highest risk groups?
Any specific preventive measures are only on an empirical basis so far, and are not substantiated by any completed clinical trials. However, I could mention for example vaccination against flu and pneumococcus or sufficient intake of vitamins C and D. Of course, the whole world is eagerly awaiting a vaccine against Covid-19. 

How can vaccination against flu and pneumococcus help against the SARS-CoV-2 virus?
Vaccination against flu reduces the risk of weakening of the organism during the time of epidemics of both illnesses. The current flu vaccination rate in the Czech Republic is 10-20% in risk persons, and approximately 5-6% in the overall population. It’s considered optimal to attain a vaccination rate of 75%. The pneumococcus vaccine aims to prevent the onset of pneumococcal diseases, which in patients with Covid-19 cause bacterial infection and thereby cause severe complications of the course of the illness, which occur in approximately one third of people infected with the SARS-CoV-2 virus. 

How does vitamin D help endangered groups?
Vitamin D has significant modulating effects on cells of the immune system, and in the majority of cells its effect is complex. It has been applied on several levels in the history of immunity medicine, for example in liquidating pathogens. It’s also used for its capacity to regulate the natural immune reaction in order to ensure that no damage to the organism occurs due to an excessive reaction, which may be caused by various allergies and autoimmune disorders. Furthermore, individuals with a low level of vitamin D suffer more often from colds and infections of the respiratory tracts. The literature and professional articles state that approximately 60-75% of the Czech population suffers from vitamin D deficiency, and so it’s useful to ensure sufficient intake of this vitamin not only for risk groups, but for the majority of the healthy population. The first way to acquire vitamin D is from sunlight. Synthesis of vitamin D takes place on the basis of penetration of UVB rays through the skin. The process of its production doesn’t take place immediately, but after 10-15 minutes of exposure. In general it’s stated that exposure to sunlight for 20 minutes at least twice a week should provide a person with sufficient vitamin D, thus the body obtains as much as 90% of the recommended amount of the vitamin by natural means. If there isn’t sufficient sunlight, another option is available – intake of the vitamin in food. The recommended doses are up to 10 000 IU/day, the regular dose is 400–2000 IU/day. The occurrence of adverse effects upon consumption of vitamin D is rare. Through exposure to sunlight it’s possible to acquire approximately 400 IU/per hour. It’s beneficial to supplement your diet with fish oil (one tablespoon contains 1300 IU), salmon (250 IU/250 g), tinned tuna (200 IU/250 g) or tinned sardines (250 IU/85 g). A third possible source of vitamin D is food supplements from a pharmacy, where you can buy drops, tablets, capsules etc. It’s necessary to pay increased attention to people with risks factors of vitamin D deficit, which include osteoporosis, obesity, darker skin pigment, use of risk drugs (e.g. glucocorticoids, antiretroviral drugs), longer periods of hospitalisation or institutionalisation, low exposure to solar radiation or malabsorption (impaired absorption of nutrients from food). In these cases it’s suitable to begin supplementing vitamin D as soon as possible. 

Vitamin C is a key component of prevention against various diseases. How does it contribute in the case of Covid -19?
Vitamin C protects the cells of the host against oxidative stress caused by infection. A number of studies have demonstrated that ascorbic acid (vitamin C) has a very positive influence on the development and maturing of T-lymphocytes, especially NK cells active in the immune response to viral substances. It also contributes to inhibiting the production of ROS (reactive oxygen species) and modulating the cytokine network, which is typical of systemic inflammatory response syndrome. With regard to evaluating the effect of vitamin C, it’s necessary to differentiate between two approaches; on the one hand supplementing regular recommended doses of vitamin C as prevention of disease, and on the other application of high doses of vitamin C intravenously as adjuvant therapy for patients already suffering from a disease. Increasing the dose of supplements may be beneficial in providing relief from symptoms and also shortening the period of convalescence. A varied diet rich in vitamin C (e.g. citrus fruit, raw vegetables) is recommended as the basis of supplementing. In order to cover increased requirements for children aged over 6 and adults, 0.2-0.5 g of vitamin C per day is recommended in the short term, and in the case of deficiency 0.5-1 g per day. In general it is not recommended to exceed a dose of 2 g of vitamin C per day within long-term prevention. It’s necessary to remember that the organism has a limited capacity to absorb more than 1 g of the vitamin following oral administration. Higher doses may lead to osmotic diarrhoea, gastrointestinal discomfort or slightly increased diuresis. The administration of high doses of vitamin C (higher than 2 g/day) also presents a risk of oxalate stones in urine. Vitamin C and its correlation with adjuvant therapy of infection with the new coronavirus is now the subject of ongoing clinical trials on Covid-19 positive patients, who are being intravenously administered high doses of 10–80g/day. We are still awaiting the results. 

How is the development of a vaccine against Covid-19 progressing?
At present we can see a very intensive endeavour to develop a specific vaccine. More than 100 scientific teams are currently working worldwide (USA, South Korea, Canada, Israel, China, EU states…) on examining 120 candidates for vaccines. The majority of the studies will conclude the second phase of research in the period of 2021–2023, after which the third phase will follow, in which the effectiveness of the vaccine will be tested on larger numbers of healthy volunteers. Only after the efficacy and above all safety of the vaccine has been confirmed can it be approved for use. 

Some sources mention that certain plant-based preparation can be used within the framework of prevention and treatment of Covid-19...
Some plant-based preparations, which are widely used mainly in China, can help reduce the incidence of complications and shorten the convalescence period. They are available either separately or in the form of medicinal compounds. These are for example Astragalus root (milkvetch), which grows only in China and Mongolia. Another is Radix glycyrrhizae (liquorice root), which strengthens the immunity, has anti-inflammatory properties and eases coughs. Myricetin is also a useful natural substance. This is a flavonoid polyphenolic compound, which is a natural inhibitor of viral enzymes, with antioxidant properties. It can be found mainly in fruit, vegetables, nuts, tea and red wine. It’s also necessary to mention zinc and its immunomodulation effects, since a zinc deficit leads to increased susceptibility to infections. Zinc can be easily absorbed through food, it’s contained for example in beef, pork and chicken, eggs, milk, cheese or wholemeal wheat products. The daily requirement is 2–10 mg. 

To conclude, can you remind us of what preventive measures the Program Health Plus clinic has introduced?
Since the very beginning of the epidemic in the Czech Republic, personal doctors at Program Health Plus have been seeking out risk clients by means of a “scoring system”, which is based on all the risk factors. We’ve attempted to ensure that chronically ill patients are provided with optimal compensation for their illness, and we’ve regularly monitored their current condition of health and adjusted their medication. At the same time, we’ve endeavoured to ensure timely detection of any applicable decompensation of chronic diseases. We’ve also sought out clients with a risk of vitamin D deficiency and recommended ways of supplementing. During the time of the announcement of anti-epidemic measures, we regularly contacted clients from risk groups, in which our main aim was to prevent anxiety and stress and to recommend suitable preventive measures. We tried to motivate clients to make the maximum use of the options of contact-free communication with doctors, for example with the aid of our mobile app or online chat service. A system of anti-epidemic measures has been set up within the clinic’s communal areas, which prevents the spread of infection between clients and staff, for example separate areas, regular disinfection, safe handling and use of protective aids, testing etc. Regular updates of preventive measures and anti-epidemic measures are continuing, based on the latest observations from scientific research and regulations from bodies of the state administration.