Opportunistic non-communicable diseases in times of COVID-19

We previously proposed the term 'opportunistic non-communicable diseases (NCDs)' to raise awareness of how NCDs thrive in societies with inadequate healthcare services. However, we did not anticipate that within the next year the new coronavirus disease (COVID-19) would sweep the globe. Lockdowns became the primary strategy for mitigation in most countries. However, the extensive restrictions and allocation of resources towards the containment of the pandemic have likely served as a catalyst of NCDs, especially in populations, societies and individuals already at high risk. We are presenting evidence to qualify two primary factors responsible for the potential impact on the development of NCDs during the COVID-19 pandemic. The first is disrupted healthcare services including avoidance and postponement of healthcare visits. The second is effects of changing lifestyle and living conditions including isolation, loss of job and income. The accumulated effect of these factors will likely further accelerate the development of NCDs and impair their management, especially in low- and middle-income countries. Insufficient vaccination coverage due to inequality in vaccine distribution and vaccine hesitancy left room for the incubation of immune-evasive variants that threatened to sustain or reinitiate the pandemic. We believe the concept of opportunistic NCDs and the potential catalytic effect that pandemics may have on the development of NCDs and their management, should be used as further arguments to secure equal vaccine distribution, promote global vaccine acceptance and to speed up and increase investments in primary health care in low- and middle-income countries to cope with the already existing NCD crisis and to prepare for future epidemics.