Summary of Significant Accounting Policies - Additional Information (Details)					1 Months Ended	12 Months Ended
	Feb. 01, 2023 USD ($)	Jan. 31, 2023 USD ($)	Oct. 01, 2022 USD ($)	Oct. 01, 2021 USD ($)	Dec. 31, 2022 USD ($) $ / shares	Dec. 31, 2022 USD ($) reporting_unit segment $ / shares shares	Dec. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)	Dec. 31, 2016 shares	Dec. 31, 2019 USD ($)	Jan. 25, 2016 $ / shares
Summary of Significant Accounting Policies [Line Items]
Cash and cash equivalents and restricted cash					$ 1,348,845,000	$ 1,348,845,000	$ 1,528,259,000	$ 648,738,000		$ 82,180,000
Net loss						(657,939,000)	(1,743,751,000)	(418,259,000)
Net cash provided by (used in) operating activities						(415,937,000)	322,946,000	(42,541,000)
Collaboration agreement upfront payment amount					819,000,000	819,000,000
Advertising costs						$ 84,000,000	8,900,000
Number of reporting units | reporting_unit						1
Impairment to goodwill			$ 0	$ 0
Income tax expense						$ 4,292,000	29,215,000	0
Foreign currency translation adjustment					(6,400,000)	(6,400,000)	(1,400,000)
Foreign currency transaction (losses) gain						$ (2,500,000)	$ (5,300,000)	$ 9,600,000
Number of operating segments | segment						1
Gavi Advance Purchase Agreement- COVAX Facility
Summary of Significant Accounting Policies [Line Items]
Collaboration agreement upfront payment amount					697,400,000	$ 697,400,000
Government Contract | USG Agreement
Summary of Significant Accounting Policies [Line Items]
Research and development arrangement, contract to perform for others, contract remaining					416,000,000	$ 416,000,000
5.00% Convertible notes due 2027 | Unsecured Debt
Summary of Significant Accounting Policies [Line Items]
Sale of common stock and issuance debt					$ 236,200,000
Number of shares issued for debt converted (in shares) | shares						16,400,000
Debt instrument, convertible, conversion price (in usd per share) | $ / shares					$ 12.50	$ 12.50
3.75% Convertible notes due 2023 | Unsecured Debt
Summary of Significant Accounting Policies [Line Items]
Number of shares issued for debt converted (in shares) | shares						16,400,000			2,385,800
Debt instrument, convertible, conversion price (in usd per share) | $ / shares					$ 136.20	$ 136.20					$ 136.20
3.75% Convertible notes due 2023 | Unsecured Debt | Subsequent Event
Summary of Significant Accounting Policies [Line Items]
Repayments of debt	$ 325,000,000	$ 325,000,000
Minimum
Summary of Significant Accounting Policies [Line Items]
Requisite service period						1 year
Maximum
Summary of Significant Accounting Policies [Line Items]
Requisite service period						4 years