Associations between clinical data, vaccination status, antibody responses, and post-COVID-19 symptoms in Thais infected with SARS-CoV-2 Delta and Omicron variants: a 1-year follow-up study

The study followed 110 COVID-19 patients in Thailand for 1 year, focusing on the Delta and Omicron variants. It found that Delta infections were associated with more severe outcomes like pneumonia, while Omicron cases had milder symptoms such as sore throat and congestion. Vaccination reduced disease severity, with fully vaccinated individuals experiencing less severe symptoms. Antibody responses varied, with Delta-specific antibodies being more pronounced in cases with pneumonia, and Omicron-specific IgA linked to hypertension and diabetes. Post-COVID-19 symptoms like fatigue and cough decreased over time, but hair loss and forgetfulness persisted, with 22.9% of participants reporting hair loss one year post-infection. The study emphasizes the importance of vaccination and monitoring post-COVID-19 symptoms, especially in vulnerable populations.