Potential ocular and systemic COVID-19 prophylaxis approaches for healthcare professionals

Abstract

The COVID-19 pandemic has brought with it, innumerable challenges in healthcare, both through the direct burden of morbidity and mortality of the disease, and also by the curtailing of other essential albeit less emergency medical services to reduce the risk of community spread. Reports from around the world are showing mounting number of cases even in healthcare professionals spite of usage of adequate personal protective equipment. There are a number of factors which could account for this, be it the affinity of the virus to the respiratory and other mucosa or to patient risk factors for developing severe forms of the disease. In view of the growing need for resuming other medical services, it is essential to find newer ways to protect ourselves better, whether by systemic or topical mucosal prophylaxis with various medications or lifestyle changes promoting wellbeing and immunity. This article discusses additional prophylactic measures including drug repurposing or new indication paradigms to render protection. Certain medications such as chloroquine, trehalose, antihistaminics, and interferons used topically for various ocular conditions with reasonably good safety records are known to have anti-viral properties. Hence, can be harnessed in preventing SARS-CoV-2 attachment, entry, and/or replication in host cells. Similarly, use of hypertonic saline for nasal and oral mucosa and dietary changes are possible methods of improving our resistance. These additional prophylactic measures can be cautiously explored by healthcare professionals to protect themselves and their patients.

Keywords: COVID-19; health care professionals; precautions; prophylaxis.

Figure 1

Scoring system to assess the risk of COVID-19 associated morbidity among healthcare professionals. This is will be used to triage the professionals and plan for appropriate additional prophylactic measures

Figure 2

Prophylaxis strategies for healthcare workers based on the prevailing risk factors

Figure 3

Schematic representation of mechanisms underlying various ocular pharmaceutical agents in preventing attachment and entry of SAR-CoV-2 in host cells. (i) Hydroxychloroquine prevents binding of SARS-CoV-2 to host cells by disrupting the interaction between viral S protein and ACE2 of host cells, by impairing glycosylation of ACE2 in host cells. (ii) Hydroxychloroquine and anti-histaminics prevent the uptake of virus by endocytosis. (iii) Hydroxychloroquine increases endosomal pH that would prevent the activation of cathepsins, an essential event for the fusion of viral and host endosomal membranes, necessary for viral entry, (iv) Trehalose facilitates endosome based degradation of virus, (v) Trehalose inhibits the activation of cathepsins, an essential event for the fusion of viral and host endosomal membranes, necessary for viral entry, (vi) Trehalose induces type 1 interferons in host cells and (vii) type 1 interferons induces interferon response genes that would prevent the viral replication and maturation