Most attempts to reduce the risk of coronavirus disease 2019 (COVID-19) have focused on developing vaccines and implementing non-drug interventions such as lockdowns and social distancing restrictions to reduce disease transmission. However, scientists from the Utrecht Institute of Pharmaceutical Sciences are exploring alternative ways to prepare for future pandemics. For example, by maintaining a healthy lifestyle, such as preventing unhealthy foods and smoking and maintaining regular exercise in the population, immune fitness can be crucial in reducing the impact of an epidemic such as functional medicine. The search was published in Journal of Clinical Medicine.
Study: Pandemic preparedness: the importance of adequate immune fitness. Image Credit: peterschreiber.media / Shutterstock
Studies
During the epidemic, two studies were designed and implemented in the Netherlands, to test variables identified through assessments of demographic and clinical data, including age, weight, underlying disease, and immune fitness (assessed by self-reported disease) for association with number and severity. A symptom of COVID-19.
Corona Lockdown: How fit are you? The study (CLOFIT) was conducted first and consisted of an anonymous online survey with participants recruited through Facebook ads. These individuals cannot be tested for COVID-19 because the study was conducted so early in the epidemic. The second study was Corona Virus Test Street Investigations (COTEST)which were conducted in testing centers and evaluated similar variables using a personal questionnaire.
In the CLOFIT study, which was conducted online during the first Dutch lockdown, a total of 1,415 participants, ages 18 to 94, were evaluated. Of these individuals, 920 reported at least one underlying chronic disease. Women tend to be smaller than men and have a lower body mass index (BMI), but they also have a lower level of immune fitness before (Immune fitness 2019) and during lockdown (Immune fitness DL). In addition, women reported more frequent and severe symptoms of COVID-19 than men. Symptoms of COVID-19 were more prevalent and severe in older individuals, but the relationship was not very strong. Immunological fitness was, as expected, closely related to both number and severity. BMI was not found to correlate with the number or severity of symptoms. Stepwise regression analysis was used to create a model to explain the variance, including gender, age, BMI, baseline disease, and immune fitness as predictive variables. Explaining 26% of the variance, this model found that the three variables that predicted the most number of symptoms were immune fitness (2019), immune fitness (DL), and having an underlying disease. In a second analysis, these also proved to be the variables that were the best predictors of risk as well.
A second analysis was performed on the COTEST study, which was conducted during a delta outbreak at healthcare testing sites, with a total of 925 participants. As this was done later in the pandemic, participants could be tested for COVID-19, revealing 88 positive cases. As expected, those who tested positive for COVID-19 reported a significantly higher average number of symptoms than those who tested negative, even though 8% were asymptomatic. This study examined immune fitness (2019) and immune fitness at the time of testing (T-immune fitness). Significant correlations between immune fitness (2019 and T) and the number/severity of symptoms. The associations between immune fitness (2019) in both groups were similar in magnitude, but associations with immune fitness (T) were significantly stronger among negative individuals. Stepwise regression analysis was again performed using the same predictive variables (with immune fitness (T) replacing immune fitness (DL). This created a model explaining 30.9% of the variance in the number of symptoms and a second model explaining 29.9% of symptom severity. In this study, The three most important factors in both models were immune fitness (T), immune fitness (2019), and gender.Immune fitness (2019).
Conclusions
According to these studies, immune fitness is the most important factor in reducing the severity and number of symptoms of COVID-19. Taking the group as a whole, immune fitness (2019) was the most important predictor, although immune fitness (T) was more significant in COTEST participants who had positive tests.
In conclusion, the authors emphasize that governments have a responsibility to not only rely on pharmaceutical interventions to prepare for future epidemics that epidemiologists expect to become more frequent, but also to strive to increase the immune fitness of the population through campaigns that encourage a healthy lifestyle.
