Convertible Promissory Notes and Long-Term Debt - Additional Information (Details) - USD ($)			3 Months Ended		6 Months Ended		12 Months Ended
	Apr. 18, 2022	Aug. 31, 2021	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021	Dec. 31, 2021
Convertible Promissory Notes [Line Items]
Change in fair value of convertible promissory notes			$ 34,396,000	$ 444,000	$ 51,469,000	$ 517,000
Interest expense				8,000,000		17,000,000
Convertible promissory notes, outstanding principal balance							$ 158,276,000
Debt instrument, carrying amount			5,000,000		5,000,000
PIK interest					21,000
Amortization of debt discount					$ 81,000
Minimum
Convertible Promissory Notes [Line Items]
Notes issuance, maturity period					12 months
Maximum
Convertible Promissory Notes [Line Items]
Notes issuance, maturity period					18 months
Term Loan
Convertible Promissory Notes [Line Items]
Interest expense			$ 200,000		$ 200,000
Debt instrument, accretion of final payment fee					100,000
PIK interest					21,000
Amortization of debt discount					11,000
Debt instrument, coupon interest					$ 100,000
Term Loan | Loan Agreement
Convertible Promissory Notes [Line Items]
Debt instrument, interest rate	4.55%		5.80%		5.80%
Debt instrument, carrying amount	$ 75,000,000.0
Debt instrument, minimum draw amount	$ 5,000,000.0
Debt instrument, basis spread on variable rate	5.00%
Debt instrument, interest rate per annum	2.85%
Debt instrument, payment terms	The monthly payments consist of interest-only through June 1, 2025 or, if prior to April 30, 2025, (x) the conditions to Term Loan 3 have been satisfied and (y) the Company has reasonably determined that (i) the HIL-214 Vaccine Trial has achieved the protocol-specified primary efficacy endpoint and (ii) HIL-214 has demonstrated acceptable safety results in the HIL-214 Vaccine Trial, and, as a result, the Company supports the initiation of a Phase 3 registrational trial as the next immediate step in the development of HIL-214, in each case subject to reasonable verification by Hercules, through June 1, 2026. Subsequent to the interest-only period, the Term Loans will be payable in equal monthly installments of principal, plus accrued and unpaid interest, through the maturity date of May 1, 2027.
Debt instrument, maturity date	May 01, 2027
Debt instrument, final payment fee	$ 2,100,000		$ 2,100,000		$ 2,100,000
Percentage of original principal amount payable	7.15%
Percentage of interest upon event of default	4.00%
Term Loan | Loan Agreement | Maximum
Convertible Promissory Notes [Line Items]
Percentage of prepayment fee on outstanding principal balance	2.00%
Term Loan | Prime Rate | Loan Agreement
Convertible Promissory Notes [Line Items]
Debt instrument, basis spread on variable rate	1.05%
Term Loan 1 | Loan Agreement
Convertible Promissory Notes [Line Items]
Debt instrument, amount borrowed	$ 5,000,000.0
Frazier
Convertible Promissory Notes [Line Items]
Aggregate amount			$ 8,500,000		$ 8,500,000
Change in fair value of convertible promissory notes				$ 400,000		$ 500,000
Frazier | Minimum
Convertible Promissory Notes [Line Items]
Bearing interest			0.12%		0.12%
Frazier | Maximum
Convertible Promissory Notes [Line Items]
Bearing interest			2.52%		2.52%
2019 Frazier Notes
Convertible Promissory Notes [Line Items]
Aggregate amount			$ 900,000		$ 900,000
2020 Frazier Notes
Convertible Promissory Notes [Line Items]
Aggregate amount			1,300,000		1,300,000
2021 Frazier Notes
Convertible Promissory Notes [Line Items]
Aggregate amount			6,300,000		$ 6,300,000
August 2021 Notes | Common Stock
Convertible Promissory Notes [Line Items]
Debt instrument conversion, common stock shares issued							10,672,138
August 2021 Notes | Note Purchase Agreement
Convertible Promissory Notes [Line Items]
Aggregate amount		$ 139,520,000
Debt instrument, interest rate		6.00%
Debt instrument, frequency of periodic payment					annually
Change in fair value of convertible promissory notes			34,400,000		$ 51,500,000
Interest expense			700,000		2,800,000
Convertible promissory notes, outstanding principal balance							$ 139,500,000
August 2021 Notes | Note Purchase Agreement | New Investors
Convertible Promissory Notes [Line Items]
Aggregate amount		$ 103,750,000
August 2021 Notes | Note Purchase Agreement | Frazier Life Sciences X, L.P.
Convertible Promissory Notes [Line Items]
Aggregate amount		10,770,000
Cash proceeds from issuance of convertible notes		$ 25,000,000.0
Term Loan 1 Borrowing through December 15, 2022 | Term Loan 1 | Loan Agreement | Maximum
Convertible Promissory Notes [Line Items]
Debt instrument, available credit under loan agreement			10,000,000.0		10,000,000.0
Term Loan 1 Borrowing through June 30, 2023 | Term Loan 1 | Loan Agreement | Maximum
Convertible Promissory Notes [Line Items]
Debt instrument, available credit under loan agreement			15,000,000.0		15,000,000.0
Term Loan 2 Borrowing through June 30, 2023 | Term Loan 2 | Loan Agreement | Maximum
Convertible Promissory Notes [Line Items]
Debt instrument, available credit under loan agreement			20,000,000.0		20,000,000.0
Term Loan 3 Borrowing through March 31, 2024 | Term Loan 3 | Loan Agreement | Maximum
Convertible Promissory Notes [Line Items]
Debt instrument, available credit under loan agreement			$ 25,000,000.0		$ 25,000,000.0