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Janssen’s COVID-19 vaccine

Janssen's COVID-19 vaccine

Janssen's COVID-19 vaccine

Janssen’s COVID-19 vaccine

In January 2020, Janssen began working with industry partners, governments and health authorities to develop a vaccine candidate to help treat COVID-19. In March 2021, the European Commission granted a conditional marketing authorisation for our first single-dose COVID-19 vaccine.[1]

Janssen’s single-dose COVID-19 vaccine, also known as JNJ-78436735 or Ad26.COV2.S, is an inactivated adenovirus vector[2] (like the common cold virus[2]) containing the DNA that codes for the coronavirus ‘spike’ protein. When a person receives the Janssen COVID-19 vaccine, their cells are used to make the ‘spike’ protein, which is then recognised by the immune system as foreign.[3]This causes an immune response which leads to antibodies (proteins that help kill off bacteria and viruses) being created. Should a vaccinated person then get infected with SARS-CoV-2, the antibodies previously generated will be able to fight it off.[3]

Our COVID-19 vaccine programme leverages Janssen’s AdVac® technology. To learn more about this technology click here.


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[1]EMEA. EMA recommends COVID-19 Vaccine Janssen for authorisation in the EU. Available from: Last accessed: July 2021.

[2]CDC. Understanding Viral Vector COVID-19 Vaccines. Available from: Last accessed: July 2021.

[3]CDC. Symptoms. Available from: Last accessed: July 2021.