Grant Agreements - Additional Information (Details) - USD ($) $ / shares in Units, $ in Thousands		1 Months Ended		3 Months Ended
	Jan. 13, 2022	Sep. 30, 2023	Sep. 30, 2022	Mar. 31, 2024	Mar. 31, 2023	Dec. 31, 2023
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Reserve for remaining estimated manufacturing expenses				$ 72,260		$ 104,220
Other current assets				4,100		7,600
VIR Biomedical Advanced Research and Development Authority | Grant revenue
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Revenue from grants				3,300	$ 14,300
Human Immunodeficiency Virus ('HIV') Grant | Maximum
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Grant awarded amount. maximum				49,900
Vaccinal Antibody Grant | Grant revenue
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Revenue from grants				1,900	$ 1,900
Vaccinal Antibody Grant | Bill And Melinda Gates Foundation
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Common stock shares purchased (in shares)	881,365
Common stock, shares purchased price (in USD per share)	$ 45.38
Common stock, shares purchased, aggregate purchase price	$ 40,000
Common stock, shares issued, fair market value	$ 28,500
Closing stock price (in USD per share)	$ 37.65
Premium received	$ 11,300
Deferred revenue				14,600		13,100
Reserve for remaining estimated manufacturing expenses				7,600		$ 9,200
BARDA
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Base period funding			$ 55,000
New funding		$ 50,100
Potential future reimbursement				$ 53,300
BARDA | development of VIR-7229 through a Phase 1 clinical trial
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
New funding		40,000
BARDA | New Monoclonal Antibody Discovery
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
New funding		10,100
BARDA | Maximum
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Maximum grant amount to be received			$ 1,000,000
Additional funding		$ 11,200