CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
Operating Activities:
Net loss	$ (897,467)	$ (240,695)
Reconciliation of net loss to net cash used in operating activities:
Depreciation and amortization	8,989	3,091
Non-cash stock-based compensation	151,457	77,602
Right-of-use assets written off	17,117	187,193
Other items, net	2,739	(3,051)
Changes in operating assets and liabilities:
Receivables, prepaid expenses and other assets	209,221	(78,788)
Accounts payable and accrued expenses	180,708	60,540
Deferred revenue	992,590	80,135
Net cash provided by operating activities	665,354	86,027
Investing Activities:
Capital expenditures	(41,122)	(12,610)
Acquisition of Novavax CZ, net of cash required	0	(164,204)
Purchases of marketable securities	(2,167)	(266,330)
Proceeds from maturities and sale of marketable securities	159,807	96,488
Net cash provided by (used in) investing activities	116,518	(346,656)
Financing Activities:
Net proceeds from sale of preferred stock	0	199,822
Net proceeds from sales of common stock	564,859	447,070
Net proceeds from the exercise of stock-based awards	21,441	(1,316)
Finance lease payments	(63,876)	(65,424)
Net cash provided by financing activities	522,424	580,152
Effect of exchange rate on cash, cash equivalents and restricted cash	(6,208)	33
Net increase in cash, cash equivalents and restricted cash	1,298,088	319,556
Cash, cash equivalents and restricted cash at beginning of period	648,738	82,180
Cash, cash equivalents and restricted cash at end of period	1,946,826	401,736
Supplemental disclosure of non-cash activities:
Sale of common stock under the Sales Agreement not settled at quarter-end	0	3,883
Right-of-use assets from new lease agreements	34,914	188,362
Capital expenditures included in accounts payable and accrued expenses	7,884	6,189
Supplemental disclosure of cash flow information:
Cash interest payments	17,768	12,188
Cash paid for income taxes	$ 6,041	$ 0