BA.5 Sub-Lineages Associated with Higher Severity of COVID-19 Infection: A Cross-Sectional Study in Indonesia

Objectives We aimed to compare the clinical severity and outcome among laboratory-confirmed Omicron variant cases admitted between January and December 2022. Methods This is a cross-sectional study conducted in Hasan Sadikin General Hospital between January and December 2022. We enrolled patients aged ≥18 years with laboratory-confirmed omicron infection. Data was collected from clinical records and a whole genome sequencing database. We compared the risk of severe symptoms and mortality, using logistic regression analysis adjusted for sex, age, comorbidities, and vaccination status. Results We enrolled 255 patients and the main sub-lineages were BA.1 (16.1%), BA.2 (11.4%), BA.5 (35.7%), XBB (22.7%), and BQ.1 (14.1%). Compared to BA.1/BA.2, BA.5 sub-lineages were associated with severe symptoms (adjusted OR of 2.9; 95% CI 1.1–8.2, p<0.05). The highest risk of severe symptoms and mortality was linked with a high number of comorbidities (adjusted OR of 7.8; 95% CI 1.7–22.4, p<0.05). Booster vaccination was protective of severity and mortality. Conclusions Disease severity was associated with BA.5 sub-lineages and multiple comorbidities.Good management is particularly important for people with comorbidities. Meanwhile, booster vaccination is also required to reduce severity and mortality.