v3.25.1
Segment information - Significant Segment Expenses (Details) - USD ($)
$ in Thousands
 3 Months Ended
Mar. 31, 2025
Mar. 31, 2024
Indirect research and development expenses:    
Total research and development expenses $ 8,290 $ 11,125
Research and Development of Immunotherapies and Vaccines    
Direct research and development expenses by program:    
Total direct research and development expenses 3,492 5,838
Change in direct research and development expenses (2,346)  
Indirect research and development expenses:    
Total indirect research and development expenses 4,798 5,287
Change In indirect research and development expenses (489)  
Total research and development expenses 8,290 11,125
Change in research and development expenses (2,835)  
Research and Development of Immunotherapies and Vaccines | Personnel-related (including share-based compensation)    
Indirect research and development expenses:    
Total indirect research and development expenses 3,944 4,335
Change In indirect research and development expenses (391)  
Research and Development of Immunotherapies and Vaccines | Facility related    
Indirect research and development expenses:    
Total indirect research and development expenses 335 390
Change In indirect research and development expenses (55)  
Research and Development of Immunotherapies and Vaccines | Other indirect costs    
Indirect research and development expenses:    
Total indirect research and development expenses 519 562
Change In indirect research and development expenses (43)  
Research and Development of Immunotherapies and Vaccines | VTP-1000 Celiac    
Direct research and development expenses by program:    
Total direct research and development expenses 982 1,374
Change in direct research and development expenses (392)  
Research and Development of Immunotherapies and Vaccines | VTP-300 HBV    
Direct research and development expenses by program:    
Total direct research and development expenses 1,350 1,913
Change in direct research and development expenses (563)  
Research and Development of Immunotherapies and Vaccines | Other clinical programs    
Direct research and development expenses by program:    
Total direct research and development expenses 741 1,767
Change in direct research and development expenses (1,026)  
Research and Development of Immunotherapies and Vaccines | Other pre-clinical programs    
Direct research and development expenses by program:    
Total direct research and development expenses 419 784
Change in direct research and development expenses (365)  
Research and Development of Immunotherapies and Vaccines | VTP-500 MERS | Personnel-related (including share-based compensation)    
Indirect research and development expenses:    
Total indirect research and development expenses $ 70 $ 140