Share-Based Compensation - Additional Information (Details) $ / shares in Units, $ in Thousands							12 Months Ended
	Apr. 22, 2021 $ / shares shares	Apr. 22, 2021 £ / shares shares	Apr. 21, 2021 $ / shares	Apr. 21, 2021 £ / shares	Apr. 08, 2021 shares	Jan. 09, 2020 USD ($) tranche $ / shares shares	Dec. 31, 2021 USD ($) $ / shares shares	Dec. 31, 2020 USD ($) $ / shares shares	Dec. 31, 2018 shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average exercise price of options granted | $ / shares							$ 13.79
Options outstanding							3,186,818	1,544,382
Number of shares reserved for issuance							5,314,738
Unrecognized compensation cost related to options | $							$ 12,524	$ 3,089
Weighted-average grant date per-share fair value of stock options granted | $ / shares							$ 10.98	$ 5.66
Aggregate intrinsic value of stock options exercised | $							$ 1,823	$ 1,000
Unrecognized compensation cost which is expected to be recognized over a weighted-average period							2 years 3 months 14 days
Stock option
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average exercise price of options granted | (per share)	$ 4.84	£ 3.49	$ 0.0004	£ 0.0003
Options outstanding	267,903	267,903
RSU
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted Stock Units						479,568
Number of awards granted						479,568
Grant date fair value of awards granted | $ / shares						$ 5.23
Aggregate shares granted as percentage of total fully diluted share capital						1.50%
Number of awards granted as a result of this antidilution provision							275,139	48,513
Incremental compensation cost as a result of the modification | $						$ 147	$ 4,420
Number of awards vested							514,923
Unrecognized compensation cost of awards other than stock options | $							$ 5,760
Unrecognized compensation cost related to RSUs | $							$ 5,760
RSU | Tranche one
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of equal tranches | tranche						239,784
RSU | Tranche two
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of equal tranches | tranche						239,784
Vaccitech plc Share Award Plan 2021 | Restricted share units, options, share appreciation rights and restricted shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options granted					3,675,680
Percentage of issued and outstanding ordinary shares available for issuance under the Plan					4.00%
Expiration period of grants					10 years
Options outstanding							2,127,920
Vaccitech plc Share Award Plan 2021 | Restricted share units, options, share appreciation rights and restricted shares | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period					1 year
Vaccitech plc Share Award Plan 2021 | Restricted share units, options, share appreciation rights and restricted shares | Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period					4 years
Enterprise Management Incentive Share Option Scheme
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period									4 years
Expiration term									10 years
Enterprise Management Incentive Share Option Scheme | RSU
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares reserved for issuance									3,530,634