Document and Entity Information - shares	6 Months Ended
	Jun. 30, 2022	Aug. 04, 2022
Cover [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Jun. 30, 2022
Document Fiscal Year Focus	2022
Document Fiscal Period Focus	Q2
Entity Registrant Name	VAXCYTE, INC.
Entity Central Index Key	0001649094
Current Fiscal Year End Date	--12-31
Entity Emerging Growth Company	false
Entity File Number	001-39323
Entity Tax Identification Number	46-4233385
Entity Address, Address Line One	825 Industrial Road
Entity Address, Address Line Two	Suite 300
Entity Address, City or Town	San Carlos
Entity Address, State or Province	CA
Entity Incorporation, State or Country Code	DE
Entity Address, Postal Zip Code	94070
City Area Code	650
Local Phone Number	837-0111
Document Quarterly Report	true
Document Transition Report	false
Entity Small Business	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		59,315,134
Entity Filer Category	Large Accelerated Filer
Entity Interactive Data Current	Yes
Entity Current Reporting Status	Yes
Title of 12(b) Security	Common Stock, $0.001 par value per share
Trading Symbol	PCVX
Security Exchange Name	NASDAQ