Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Operating activities
Net loss	$ (105,538)	$ (32,128)	$ (55,744)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	4,844	4,297	4,777
Amortization of premium (accretion of discount) on marketable securities	2,781	490	(1,457)
Stock-based compensation	23,241	11,917	10,312
Noncash lease expenses	4,929
Unrealized loss (gain) on equity securities	4,454	(41,498)
Remeasurement of liability awards	(12)	19	(115)
Other	1,242	587	468
Changes in operating assets and liabilities:
Accounts receivable	(6,895)	739	(3,809)
Prepaid expenses and other assets	(3,959)	(80)	(1,441)
Accounts payable	6,433	(947)	2,253
Accrued compensation	2,594	2,806	(200)
Other liabilities	2,141	22	186
Deferred rent		931	(67)
Deferred revenue	(15,207)	(14,957)	(20,186)
Change in operating lease liability	(2,727)
Net cash used in operating activities	(81,679)	(67,802)	(65,023)
Investing activities
Purchases of marketable securities	(248,727)	(130,741)	(196,226)
Maturities of marketable securities	148,250	116,385	128,576
Sales of marketable securities	18,476	22,000	20,000
Purchases of equipment and leasehold improvements	(15,323)	(7,129)	(3,481)
Proceeds from exercise of options for Vaxcyte shares	9	89
Net cash (used in) provided by investing activities	(97,315)	604	(51,131)
Financing activities
Proceeds from sales of common stock, net of issuance costs		251,415	(327)
Proceeds from debt refinancing		25,000
Payments of debt		(10,000)	(5,000)
Proceed from exercise of common stock options	2,485	1,861	180
Taxes paid related to net share settlement of restricted stock units	(987)	(314)	(297)
Return and retirement of common stock	(7)
Proceeds from employee stock purchase plan	1,765	1,285	1,260
Net cash provided by (used in) financing activities	3,256	269,247	(4,184)
Net (decrease) increase in cash, cash equivalents and restricted cash	(175,738)	202,049	(120,338)
Cash, cash equivalents and restricted cash at beginning of year	207,024	4,975	125,313
Cash, cash equivalents and restricted cash at end of year	31,286	207,024	4,975
Supplemental disclosure of cash flow information
Cash paid for interest	2,046	1,675	1,049
Income tax paid	103
Supplemental Disclosures of Non-cash Investing and Financing Information
Purchase of property and equipment included in accounts payable	370	546	270
Remeasurement of operating lease right-of-use assets for lease modification	4,227
Offering costs included in accounts payable		361
Embedded interest associated with program fees	$ 610	1,852	$ 3,144
Warrants issued to lenders		$ 619