Condensed Statements of Operations (Parenthetical) (Unaudited) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2022	Mar. 31, 2021
Income Statement [Abstract]
Research and development expense to related party	$ 0	$ 1,612

Research and development expense to related party.

No definition available.

Name:	pcvx_ResearchAndDevelopmentExpenseToRelatedParty
Namespace Prefix:	pcvx_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration