ChAdOx1 nCoV-19 vaccine: asymptomatic efficacy estimates

An Overview of Vaccines against SARS-CoV-2 in the COVID-19 Pandemic Era

The emergence of SARS-CoV-2 in late 2019 led to the COVID-19 pandemic all over the world. When the virus was first isolated and its genome was sequenced in the early months of 2020, the efforts to develop a vaccine began. Based on prior well-known knowledge about coronavirus, the SARS-CoV-2 spike (S) protein was selected as the main target. Currently, more than one hundred vaccines are being investigated and several of them are already authorized by medical agencies. This review summarizes and compares the current knowledge about main approaches for vaccine development, focusing on those authorized and specifically their immunogenicity, efficacy preventing severe disease, adverse side effects, protection, and ability to cope with emergent SARS-CoV-2 variants.

Sudden Sensorineural Hearing Loss Following the Second Dose of COVID-19 Vaccine

Sudden sensorineural hearing loss (SSHL) is a common otolaryngology emergency that significantly affects the patient's quality of life. Although in most cases its etiology remains unknown (idiopathic SSHL), viral infections and vascular compromise constitute the most widely accepted etiopathogenic mechanisms. Specifically, occlusion of the internal auditory artery has been reported in cases of sudden deafness. Thrombotic events following the Oxford-AstraZeneca COVID-19 vaccine are rare. There have been reports of SSHL following immunization with Pfizer and Moderna COVID-19 vaccine; however, no etiologic relationship has been established between the two entities yet. We present a unique case of SSHL following the second dose of the Oxford-AstraZeneca COVID-19 vaccine. A 61-year-old female was referred to our department with a four-day history of the right-sided sense of fulness combined with almost complete hearing loss that had started two days after the second dose of Oxford-AstraZeneca COVID-19 vaccine. Pure tone audiometry showed profound right-sided sensorineural hearing loss. Magnetic resonance imaging of the brain and internal auditory canal and magnetic resonance angiography were both normal. The combination of glucocorticoids and acetylsalicylic acid leads to almost full recovery 15 days after deafness. The COVID-19 era is full of new challenges and clinical dilemmas. In our case, the addition of acetylosalicid acid to the patient's initial treatment may have contributed to the hearing restoration; however, this fact will remain a hypothesis.