Modified chimpanzee virus in AstraZeneca vaccine isn’t linked to monkeypox

31 May 2022
What was claimed

Monkeypox is linked to the chimpanzee virus used in the AstraZeneca Covid-19 vaccine

Our verdict

Although the vaccine contains a modified virus that usually infects chimpanzees, this cannot lead to monkeypox or any other disease in humans.

A Facebook post falsely suggests that there is a link between the recent rise in monkeypox cases and a key component of the AstraZeneca Covid-19 vaccine. 

The post features a screenshot from a real government information page listing the ingredients contained within the AstraZeneca vaccine. These include “recombinant, replication-deficient chimpanzee adenovirus vector encoding the SARS-CoV-2 Spike glycoprotein”.

The post questions whether the disease should be called “Chimpanzeepox” rather than monkeypox, suggesting a link between the AstraZeneca vaccine and the recent outbreak of monkeypox. 

While it is true that the AstraZeneca vaccine does contain a type of virus derived from chimpanzees, it is not from the same family of diseases responsible for monkeypox. 

Adenoviruses are common viruses that typically cause a mild cold or flu-like illness. The monkeypox virus belongs to an entirely separate family of diseases known as orthopoxviruses and leads to a disease that looks similar to smallpox, to which it is related. 

The adenovirus used in the AstraZeneca vaccine has been weakened and modified to ensure it does not cause any disease in those who receive it. 

“It is wholly different from monkeypox and there is no possibility whatsoever that the two are linked,” Ian Jones, professor of virology at the University of Reading told fact checkers at Reuters

As we’ve previously reported, the chimpanzee virus is used because it generates a strong immune response, and humans are less likely to have pre-existing antibodies against it than if a strain of virus which normally affects humans was used. 

This modified virus is used as a vector to carry the genetic information encoding the SARS-CoV-2 spike protein (a protein on the spike of the virus which causes Covid-19). When the vaccine enters cells in the body, the genetic code is used to produce the spike protein. This allows the immune system to develop antibodies to protect from Covid-19 infection in the future. The modified virus has been genetically modified so that it cannot grow or cause infection in humans.

Mark Slifka, a microbiology and immunology expert and professor at the Oregon National Primate Research Center, told the Associated Press: “Adenoviruses are adenoviruses, they are not poxviruses. They are completely different families and have no relationship whatsoever to each other.”

Chimpanzees and monkeys are different animals, which the Facebook post does not acknowledge,  but Professor Slifka added that monkeypox is also very rarely spread by monkeys.

We have also published checks on false claims that monkeypox is a side effect of Covid-19 vaccines and that the rise in cases is the result of the use of vaccines. 

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