Increased prevalence of mild myopathic changes in the post-COVID-19 duration.

OBJECTIVE: There are reports of peripheral nerve and muscle involvement during or after coronavirus disease 2019 (COVID-19), even following a mild infection. Here, we aimed to analyze the objective findings regarding peripheral nerve, neuromuscular junction, and muscle function using electrophysiology in patients with a previous COVID-19 infection. METHODS: All consecutive patients with a history of COVID-19 were questioned for post-COVID-19 duration-related neurological complaints via Composite Autonomic Symptom Score-31 (COMPASS-31), modified Toronto Neuropathy score (mTORONTO), and Fatigue Severity Scale (FSS). Patients were dichotomized into two groups based on their scores in the questionnaire. Group 1 (patients with high scores in any area of the questionnaire) and Group 2 (patients with normal scores in all sections of the questionnaire). In the second step, Group 1 was invited to a preplanned hospital visit for electrophysiological analysis, including nerve conduction studies, repetitive nerve stimulation, needle electromyography (EMG), quantitative motor unit potential analysis (qMUP), and single fiber EMG. We included 106 patients in the study. According to the questionnaire, 38 patients constituted Group 1, and 68 formed Group 2. RESULTS: Of the 38 patients, 14 accepted and underwent preplanned electrophysiological examinations. Needle EMG revealed small, short, polyphasic MUPs with early recruitment, and qMUP analysis demonstrated an increased percentage of polyphasic potentials in three patients. The examinations in other patients were unremarkable. CONCLUSIONS: The high prevalence of complaints and objective myopathic findings in our cohort implicated the role of muscle involvement in the post-COVID-19 duration. Considering the socioeconomic and psychological burden of the post-COVID-19 duration among individuals and societies, a better understanding of the symptoms and myopathy is warranted.

Effectiveness of the BNT162b2 and the CoronaVac vaccines and boosters in healthcare workers.

The evidence on the waning protection of COVID-19 vaccines has been reviewed by the World Health Organization and has led to consideration of the need for booster doses. This study aimed to evaluate vaccine effectiveness against COVID-19, and the COVID-19 infections among healthcare workers who received various types (inactive or m-RNA) and doses (2 to 4 doses) of the COVID-19 vaccine. The study was conducted with a total of 3,009 healthcare workers between August 1 and November 30, 2021 at a university hospital. Six different vaccination statuses were evaluated in the study. The effectiveness for COVID-19 infection, after adjusting for age, sex, and position, was highest in those who received two doses of CoronaVac and two doses of BNT162b2 (89.3%, 95% CI 72.2-95.9%) and was lowest in those who received two doses of CoronaVac (29%, 95% CI - 8-53%). The adjusted effectiveness of two doses of CoronaVac for COVID-19 infection was not significant (21.0%, 95% CI - 20.7-48.3%) but increased significantly with a booster dose of CoronaVac or BNT162b2. One or two doses of the BNT162b2 booster demonstrated higher effectiveness in comparison to a single dose of the CoronaVac booster. These results indicate the need for a booster dose, and heterologous boosting with BNT162b2 may be a better option for higher effectiveness for those who received two doses of CoronaVac. Future studies should evaluate the need for further booster doses and their long-term effects.