Results
PDT-treated, itching, chest tightness, headache
ADVERSE EVENTS, REINFECTION OF, SARS-COV-2 INFECTION, RECRUITMENT
Seventy-nine patients were screened between December 2021, and February 2022. One was excluded for not meeting the inclusion criteria. Of the 78 patients randomized 1:1, two patients abandoned the treatment group (one for local irritation, the other for personal reasons), and one patient abandoned the placebo group (for personal reasons). Seventy-five patients completed the study and were included in the analyses. Retention rate was 96.1% (Flow Chart of patient recruitment. RR , Retention Rate Rate; PDT , Photodynamic Treatment; Ag, Antigen; EOT, End of Treatment; D,Day; W, Week.The study-population consisted of mostly young healthy adults, with mild symptoms, naïve to natural SARS-CoV-2 infection (79%) with a complete course of vaccination (93%), and a high viral load (Patients’ baseline characteristics.SD, Standard deviation; PDT, Photodynamic Treatment. Bold values = p<0.05.Patients in the PDT arm showed a significant decrease in the Results of infectivity assays and RT-PCR on Nasopharyngeal Swabs. Risk of infectivity capacity according to PCR test delta-Ct at days 2 and 7.*Adjusted by sex, age, number of symptoms, COVID vaccine, Booster dose of COVID vaccine, and reinfection of SARS-CoV-2.PDT, Photodynamic Therapy. Bold values = p<0.05.During the study, both groups presented increased PCR cycle counts, although PDT-treated patients showed a significant difference in both E and N genes at day 7. Antibody quantification at 10 and 20 weeks showed no differences in the production of anti-spike (Results of humoral immunity assays. Patients were followed up after intranasal PDT treatment for 20 weeks. On week 10 and week 20, a sample of plasma and peripheral CD4 and CD8 T lymphocyte was collected Results of cellular immunity assays. Quantiferon assay was used to analyse the specific T-cell responses against specific purified peptides from the spike antigen (S1, S2, RBD subdomains) either using isolated CD4 COVID-19 RNA sequencing was successful in 72 patients (96%). The results indicate that 97.2% of patients were infected with Omicron 21K variant (B.1.1.529 or BA.1) one with Omicron 21L (BA.2) and one with Delta 21J (When analysing the progression of symptoms at day 3 and 7, a significant decrease in chest tightness and headache was observed in the PDT-treated group (COVID19 symptoms detected during the clinical trial.PDT, Photodynamic Therapy. Bold values = p<0.05..Regarding intervention safety, 32 patients (5 in the control group and 27 in the intervention group) reported a total of 53 mild adverse events. One patient in the intervention group dropped out due to local itching after first PDT (