As media headlines continue to attribute the overwhelming majority of hospitalized COVID-19 cases to unvaccinated people, little attention is focused on the interaction of social, biological, and nutritional determinants underlying hospitalizations. Visit the emergency department of most hospitals at any time, and you are likely to find patients with low socioeconomic status (SES). These patients are also more likely to be obese and overweight, have chronic health conditions like diabetes, chronic kidney disease, hypertension, and cardiovascular diseases, and they are more likely to have lower nutritional status from ingesting highly processed foods containing excessive calories, fat, sugar, and salt. How do all these factors potentially interact to affect COVID-19 hospitalizations, and where does vaccine hesitancy stand in relation to these factors?
The word “syndemic” refers to compromised health and deprived social conditions that interact and synergistically increase a population’s vulnerability to epidemics and pandemics. The high prevalence of chronic diseases in our society increases the population’s vulnerability to infection during the COVID-19 pandemic, evidenced by the fact that many chronic conditions are comorbid with COVID-19.
Moreover, vulnerability to infection is further increased in segments of the population with low SES within whom chronic conditions have the highest prevalence.
Obesity and Nutrition
Centers for Disease Control and Prevention (CDC) previously reported that 78% of people hospitalized with COVID-19 are either obese (50.2%) or overweight (27.8%). A diet of ultra-processed foods high in additives is associated with obesity and being overweight. Furthermore, social conditions that contribute to obesity in low SES communities include food deserts with poor availability of fresh healthy foods.
Nutritional status also is an important factor in immunity that is relevant to COVID-19. Sodium toxicity from dietary salt has been potentially implicated as a cause of COVID-19 and SARS-CoV-2 infection.
Hospitalizations versus Ambulatory Care
People with lower SES prefer acute care services provided in hospitals, which they find are more affordable, easier to access and have greater quality than ambulatory care located in private offices of primary healthcare providers.
People with lower SES who show up at the hospital also may be more inclined to delay seeking care until their illness is more serious.
Vaccine Hesitancy and SES
Obviously, vaccines do not address the many underlying and interacting social, biological, and nutritional causes in syndemics. Yet, the media continues to blame vaccine hesitancy for COVID-19 hospitalizations.
In the figure below, people with low SES have more vaccine hesitancy (Letter A in the figure), such as in Black and Hispanic communities. Vaccine hesitancy is also associated with increased hospitalization (C in the figure). However, the association of vaccine hesitancy and increased hospitalization appears to be mediated by poor health and adverse social conditions in low SES segments of the population (Letter B), not by lack of vaccination!
Furthermore, COVID-19 mRNA vaccines have ultralow absolute risk reductions of approximately 1%, and they are unlikely to have any impact at all on reducing hospitalizations. Just because healthy people in the vaccine clinical trials did not have an increased risk of hospitalization doesn’t mean the vaccines prevented hospitalizations.
Rather than attempting to contain and manage pandemic infections with vaccines, masks, social distancing, and lockdowns, directly addressing the underlying causes of syndemics is a more promising public health strategy to reduce epidemics, pandemics, and hospitalizations.