Hyperbaric Oxygen Therapy for Sudden Sensorineural Hearing Loss after Failure from Oral and Intratympanic Corticosteroid

Systemic and intratympanic steroids are most widely used for treating idiopathic sudden sensorineural hearing loss. Other treatments include vasodilator, immunosuppressant and antiviral medication. However, only 61% of patients achieve full recovery, and controversies about the standard treatment still exist. In this case report, we present a patient with idiopathic sudden sensorineural hearing loss who failed to respond to systemic and intratympanic steroid treatments but subsequently recovered after undergoing hyperbaric oxygen therapy.

SARS-CoV-2 variants of concern exhibit reduced sensitivity to live-virus neutralization in sera from CoronaVac vaccinees and naturally infected COVID-19 patients

Recent surges in SARS-CoV-2 variants of concern (VOCs) call for the need to evaluate levels of vaccine-and infection-induced SARS-CoV-2 neutralizing antibodies (NAbs). CoronaVac (Sinovac Biotech, Beijing, China) is currently being used for mass vaccination in Thailand as well as other low-income countries. Three VOCs currently circulating within Thailand include the B.1.1.7 (Alpha), B.1.351 (Beta), and B.1.617.2 (Delta) strains. We assessed NAb potency against the prototypic strain containing the original spike sequence (WT) compared to that against the 3 VOCs using sera derived from a cohort of healthcare workers who received a full 2-dose regimen of CoronaVac. Sera from two other cohorts consisting of COVID-19 patients who had been hospitalized in 2020 and 2021 were evaluated for comparison. We found that, despite equally robust production of S1-RBD-binding IgG and 100% seropositivity, sera from both CoronaVac vaccinees and naturally infected individuals had significantly reduced neutralizing capacity against all 3 VOCs compared to WT. Strikingly, NAb titers against Alpha and Beta were comparable, but Delta appears to be significantly more refractory to NAbs in all groups. Our results may help inform on CoronaVac NAb-inducing capacity, which is a proxy for vaccine efficacy, in the context of the WT strain and 3 VOCs. Our results also have critical implications for public health decision-makers who may need to maintain efficient mitigation strategies amid a potentially high risk for infection with VOCs even in those who have been previously infected.

A randomized, placebo-controlled trial of a nasal spray solution containing broadly potent neutralizing antibodies against SARS-CoV-2 variants in healthy volunteers

Successful COVID-19 prevention requires additional measures beyond vaccination, social distancing, and masking. A nasal spray solution containing human IgG1 antibodies against SARS-CoV-2 (COVITRAP) was developed to strengthen other COVID-19 preventive arsenals. Here, we evaluated its pseudovirus neutralization potencies, preclinical and clinical safety profiles, and intranasal SARS-CoV-2 inhibitory effects in healthy volunteers (NCT05358873). COVITRAP exhibited broadly potent neutralizing activities against SARS-CoV-2 with PVNT50 values ranging from 0.0035 to 3.1997 g/ml for the following variants of concern (ranked from lowest to highest): Alpha, Beta, Gamma, Ancestral, Delta, Omicron BA.1, Omicron BA.2, Omicron BA.4/5, and Omicron BA.2.75. It demonstrated satisfactory preclinical safety profiles based on evaluations of in vitro cytotoxicity, skin sensitization, intracutaneous reactivity, and systemic toxicity. Its intranasal administration in rats did not yield any detected circulatory levels of the human IgG1 anti-SARS-CoV-2 antibodies at any time point during the 120 hours of follow-up. A double-blind, randomized, placebo-controlled trial (RCT) was conducted on 36 healthy volunteers who received either COVITRAP or a normal saline nasal spray at a 3:1 ratio. Safety of the thrice-daily intranasal administration for 7 days was assessed using nasal sinuscopy, adverse event recording, and self-reporting questionnaires. COVITRAP was well tolerated, with no significant adverse effects in healthy volunteers for the entire 14 days of the study. The intranasal SARS-CoV-2 inhibitory effects of COVITRAP were evaluated in nasal fluids taken from volunteers pre- and post-administration using a SARS-CoV-2 surrogate virus neutralization test. SARS-CoV-2 inhibitory effects in nasal fluids collected immediately or six hours after COVITRAP application were significantly increased from baseline for all three variants tested, including Ancestral, Delta, and Omicron BA.2. In conclusion, COVITRAP was safe for intranasal use in humans to provide SARS-CoV-2 inhibitory effects in nasal fluids that lasted at least six hours. Therefore, COVITRAP can be considered an integral instrument for COVID-19 prevention.