ABSTRACT
Background: Previous studies showed that Favipiravir, a selective viral ribonucleic acid dependent-ribonucleic acid polymerase inhibitor, exhibited a trend of clinical improvement within 14 days and promoted viral clearance by day 7, without reduction of mortality rate in COVID-19. Methods: During the COVID-19 pandemic, Department of Medical Services (Thailand) formulated National Clinical Treatment Guidelines for COVID-19 and approved Favipiravir to eight medical centres. After treatment with Favipiravir monotherapy, we compared real-world data analysis to supportive treatment without antiviral agents. Findings: We analysed 12,888 COVID-19 patients between June 1, 2021, and July 31, 2021. This group study excluded 66 asymptomatic and 4634 COVID-19 patients treated with other antiviral agents. The 4896 mild, 2357 moderate, and 935 severe COVID-19 patients were analysed. All patients neither had previous SARS-CoV-2 infection nor received an mRNA vaccine during study period. Favipiravir monotherapy reduced the 28-day mortality risk in severe COVID-19 by relative risk (RR) = 0.72 (95% CI 0.58-0.91 P = 0.006) after adjustment for aging and hypertension. However, in mild and moderate COVID-19, Favipiravir monotherapy did not significantly reduce 28-day mortality risk by RR = 0.59 (95% CI 0.06-5.43 P = 0.65) after adjustment for aging, and RR = 0.60 (95% CI 0.32-1.13 P = 0.11) after adjustment for aging and obesity, respectively. In the patient with recovery, Favipiravir monotherapy exhibited a shortening time to recovery when compared to supportive treatment without antiviral agents (mean ± SD by 9.6 ± 7.1 vs. 12.9 ± 7.6 days: P < 0.0001, 10.0 ± 5.9 vs. 12.4 ± 5.3 days: P < 0.0001, and 11.2 ± 7.8 vs. 13.1 ± 8.0 days: P < 0.0001 in mild, moderate, and severe COVID-19 respectively). Interpretation: Real-world data analysis showed that favipiravir monotherapy was superior to supportive treatment without antiviral agents in shortening the recovery time in surviving patients and significantly reducing 28-day mortality risk in severe COVID-19. Funding: Department of Medical Services, Ministry of Public Health, Thailand.
ABSTRACT
The global COVID-19 pandemic, caused by the novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), was first detected in China in December 2019. To date, there have been approximately 3.4 million reported cases of COVID-19 and over 24,000 deaths in Thailand. In this study, we investigated the molecular characteristics and evolution of SARS-CoV-2 in Thailand from 2020 to 2022. Two hundred sixty-eight SARS-CoV-2 isolates, collected mostly in Bangkok from COVID-19 patients, were characterised by partial genome sequencing. Moreover, the viruses in 5,627 positive SARS-CoV-2 samples were identified as viral variants - B.1.1.7 (Alpha), B.1.617.2 (Delta), B.1.1.529 (Omicron/BA.1), or B.1.1.529 (Omicron/BA.2) - by multiplex real-time reverse transcription polymerase chain reaction (RT-PCR) assays. The results revealed that B.1.36.16 caused the predominant outbreak in the second wave (December 2020-January 2021), B.1.1.7 (Alpha) in the third wave (April-June 2021), B.1.617.2 (Delta) in the fourth wave (July-December 2021), and B.1.1.529 (Omicron) in the fifth wave (January-March 2022). The evolutionary rate of the viral genome was 2.60 × 10-3 (95% highest posterior density [HPD], 1.72 × 10-3 to 3.62 × 10-3) nucleotide substitutions per site per year. Continued molecular surveillance of SARS-CoV-2 is crucial for monitoring emerging variants with the potential to cause new COVID-19 outbreaks.
Subject(s)
COVID-19 , SARS-CoV-2 , Humans , SARS-CoV-2/genetics , COVID-19/epidemiology , Thailand/epidemiology , PandemicsABSTRACT
Coronavirus disease 2019 (COVID-19) is a severe and frequently lethal disease caused by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) that surfaced in Thailand in early 2020. As of this writing, there have been 3,303,169 reported cases and 24,075 deaths in Thailand. This study investigated molecular characterisation and the evolution of the SARS-CoV-2 identified during 2020–2022 in Thailand. Two hundred and sixty-eight SARS-CoV-2 strains, collected mostly in Bangkok during 2020–2022 from COVID-19 patients, were characterised by partial genome sequencing. Moreover, 5,627 positive SARS-CoV-2 samples were identified as variants of the virus (GRY/Alpha, GK/delta, GRA/Omicron BA.1 and GRA/Omicron BA.2) by multiplex real-time reverse transcription-polymerase chain reaction (RT-PCR) assays. The results revealed that clade GH caused the predominant outbreak in the second wave (December 2020–January 2021), clade GRY/Alpha in the third wave (April–June 2021), clade GK/delta in the fourth wave (July–December 2021), and clade GRA/Omicron in the fifth wave (January–March 2022). The evolutionary rate in the outbreak was 2.60×10 − 3 (95% highest posterior density [HPD], 1.72×10 − 3 to 3.62×10 − 3 ) nucleotide substitutions per site per year. Continued molecular surveillance of SARS-CoV-2 is crucial for monitoring emerging variants to prevent possible new COVID-19 outbreaks.