Effect of Previous COVID-19 Vaccination on Humoral Immunity 3 Months after SARS-CoV-2 Omicron Infection and Booster Effect of a Fourth COVID-19 Vaccination 2 Months after SARS-CoV-2 Omicron Infection.

In this study, we aimed to determine the effect of COVID-19 vaccination on 3-month immune response and durability after natural infection by the Omicron variant and to assess the immune response to a fourth dose of COVID-19 vaccination in patients with prior natural infection with the Omicron variant. Overall, 86 patients aged ≥60 years with different vaccination histories and 39 health care workers (HCWs) vaccinated thrice before Omicron infection were enrolled. The sVNT50 titer was significantly lower in patients with incomplete vaccination before SARS-CoV-2 infection with the S clade (p < 0.001), Delta variant (p < 0.001), or Omicron variant (p = 0.003) than in those vaccinated thrice. The sVNT results against the Omicron variant did not differ significantly in patients aged ≥60 years (p = 0.49) and HCWs (p = 0.17), regardless of the recipient receiving the fourth dose 2 months after COVID-19. Incomplete COVID-19 vaccination before Omicron infection for individuals aged ≥60 years conferred limited protection against homologous and heterologous virus strains, whereas two or three doses of the vaccine provided cross-variant humoral immunity against Omicron infection for at least 3 months. However, a fourth dose 2 months after Omicron infection did not enhance immunity against the homologous strain. A future strategy using the bivalent Omicron-containing booster vaccine with appropriate timing will be crucial.

Effectiveness of methylprednisolone therapy in patients with a high-risk common type of COVID-19 pneumonia: a retrospective cohort study.

The optimal timing of glucocorticoid treatment for coronavirus disease 2019 (COVID-19) pneumonia is uncertain. We evaluated the clinical outcomes of methylprednisolone therapy (MPT) for patients with a high-risk common type (HRCT) COVID-19 pneumonia. We conducted a multicenter retrospective cohort study in Northeast China. A comparison was performed between the standard treatment (SDT) group and the SDT + MPT group to determine the efficacy of methylprednisolone in treating HRCT COVID-19 pneumonia. We collected the medical records of 403 patients with HRCT COVID-19 pneumonia (127 in the SDT + MPT group and 276 in the SDT group). None of the patients had received mechanical ventilation or died. Furthermore, there were no side effects associated with MPT. Patients in the SDT + MPT group treated with methylprednisolone received an intravenous injection for a median interval of five days (interquartile range of 3 to 7 days). The trends in lymphocyte count, C-reactive protein, interleukin 6, lactic acid dehydrogenase, respiratory rate, SpO2, PaO2, D-dimer and body temperature were similar between the SDT + MPT and SDT groups. The results for the SDT + MPT group seemed to improve faster than those for the SDT group; however, the results were not statistically significant. Clinical outcomes revealed that the average hospitalized days and the rate of progression to severe type COVID-19 pneumonia in both the SDT + MPT group and the SDT group were 14.56 ± 0.57 days versus 16.55 ± 0.3 days (p = 0.0009) and 21.26% (27/127) versus 32.4% (89/276) (p = 0.0247), respectively. The 16-day nucleic acid negative rate was higher in the SDT + MPT group than in the SDT group, 81.73% (104/127) versus 65.27% (180/276) (p = 0.0006). MPT effectively prevents patients with HRCT COVID-19 pneumonia from progressing to the severe stage.

Surgical strategy and optimal timing of tracheostomy in patients with COVID-19: Early experiences in Japan.

OBJECTIVE: Tracheostomy is an important surgical procedure for coronavirus disease-2019 (COVID-19) patients who underwent prolonged tracheal intubation. Surgical indication of tracheostomy is greatly affected by the general condition of the patient, comorbidity, prognosis, hospital resources, and staff experience. Thus, the optimal timing of tracheostomy remains controversial. METHODS: We reviewed our early experience with COVID-19 patients who underwent tracheostomy at one tertiary hospital in Japan from February to September 2020 and analyzed the timing of tracheostomy, operative results, and occupational infection in healthcare workers (HCWs). RESULTS: Of 16 patients received tracheal intubation with confirmed severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, five patients (31%) received surgical tracheostomy in our hospital. The average consultation time for surgical tracheostomy was 7.4 days (range, 6 - 9 days) from the COVID-19 team to the otolaryngologist. The duration from tracheal intubation to tracheostomy ranged from 14 to 27 days (average, 20 days). The average time of tracheostomy was 27 min (range, 17 - 39 min), and post-wound bleeding occurred in only one patient. No significant differences in hemoglobin (Hb) levels were found between the pre- and postoperative periods (mean: 10.2 vs. 10.2 g/dl, p = 0.93). Similarly, no difference was found in white blood cell (WBC) count (mean: 12,200 vs. 9,900 cells /µl, p = 0.25). After the tracheostomy, there was no occupational infection among the HCWs who assisted the tracheostomy patients during the perioperative period. CONCLUSION: We proposed a modified weaning protocol and surgical indications of tracheostomy for COVID-19 patients and recommend that an optimal timing for tracheostomy in COVID-19 patients of 2 - 3 weeks after tracheal intubation, from our early experiences in Japan. An experienced multi-disciplinary tracheostomy team is essential to perform a safe tracheostomy in patients with COVID-19 and to minimize the risk of occupational infection in HCWs.