ABSTRACT
Objectives: This study aimed to determine the safety and immunogenicity of a combined intramuscular/intranasal recombinant spike protein COVID-19 vaccine (RCP). Methods: We conducted a randomized, double-blind, placebo-controlled, phase I trial. Three vaccine strengths were compared with an adjuvant-only preparation. It included two intramuscular and a third intranasal dose. Eligible participants were followed for adverse reactions. Specific IgG, secretory IgA, neutralizing antibodies, and cell-mediated immunity were assessed. Results: A total of 153 participants were enrolled (13 sentinels, 120 randomized, 20 non-randomized open-labeled for IgA assessment). No related serious adverse event was observed. The geometric mean ratios (GMRs) and 95% CI for serum neutralizing antibodies compared with placebo two weeks after the second injection were 5.82 (1.46-23.13), 11.12 (2.74-45.09), and 20.70 (5.05-84.76) in 5, 10, and 20 µg vaccine groups, respectively. The GMR for anti-RBD IgA in mucosal fluid two weeks after the intranasal dose was 23.27 (21.27-25.45) in the 10 µg vaccine group. The humoral responses were sustained for up to five months. All vaccine strengths indicated a strong T-helper 1 response. Conclusion: RCP is safe and creates strong and durable humoral and cellular immunity and good mucosal immune response in its 10 µg /200 µL vaccine strengths. Trial registration: IRCT20201214049709N1.
ABSTRACT
BACKGROUND: We performed a multicenter, randomized open-label trial in patients with moderate to severe Covid-19 treated with a range of possible treatment regimens. METHODS: Patients were randomly assigned to one of three regimen groups at a ratio of 1:1:1. The primary outcome of this study was admission to the intensive care unit. Secondary outcomes were intubation, in-hospital mortality, time to clinical recovery, and length of hospital stay (LOS). Between April 13 and August 9, 2020, a total of 336 patients were randomly assigned to receive one of the 3 treatment regimens including group I (hydroxychloroquine stat, prednisolone, azithromycin and naproxen; 120 patients), group II (hydroxychloroquine stat, azithromycin and naproxen; 116 patients), and group III (hydroxychloroquine and lopinavir/ritonavir (116 patients). The mean LOS in patients receiving prednisolone was 5.5 in the modified intention-to-treat (mITT) population and 4.4 days in the per-protocol (PP) population compared with 6.4 days (mITT population) and 5.8 days (PP population) in patients treated with Lopinavir/Ritonavir. RESULTS: The mean LOS was significantly lower in the mITT and PP populations who received prednisolone compared with populations treated with Lopinavir/Ritonavir (p = 0.028; p = 0.0007). We observed no significant differences in the number of deaths, ICU admission, and need for mechanical ventilation between the Modified ITT and per-protocol populations treated with prednisolone and Lopinavir/Ritonavir, although these outcomes were better in the arm treated with prednisolone. The time to clinical recovery was similar in the modified ITT and per-protocol populations treated with prednisolone, lopinavir/ritonavir, and azithromycin (P = 0.335; P = 0.055; p = 0.291; p = 0.098). CONCLUSION: The results of the present study show that therapeutic regimen (regimen I) with low dose prednisolone was superior to other regimens in shortening the length of hospital stay in patients with moderate to severe COVID-19. The steroid sparing effect may be utilized to increase the effectiveness of corticosteroids in the management of diabetic patients by decreasing the dosage.