Fact Check-COVID-19 vaccines do not weaken people’s immune systems ‘like chemotherapy’

A British funeral director who has previously spread misinformation online has made multiple false claims about COVID-19 vaccines and their side effects in a video shared widely on social media.

The footage has attracted hundreds of thousands of views on Twitter (here), and tens of thousands of views on Facebook and Bitchute (here, here, here, here, here and here , here, here, here and here).

It features Milton Keynes-based John O’Looney, who claims COVID-19 vaccines stop immune systems from fighting off the Omicron variant, which he says is another name for the common cold.

O’Looney also compares this alleged effect to chemotherapy, a treatment for cancer that can hinder immunity due to reducing white blood cells produced by the bone marrow (here and here).

“So, they’ve had the jabs maybe six to eight months ago and it’s been eating away at their immune system – and now they’re struggling to fight off things like the common cold,” O’Looney says in the clip.

“The government are very quick to label it the Omicron… they’re sick with the common cold. Their immune system is decimated.

“If you think about it logically much like, for example, a cancer patient. So, when you get a cancer patient and they’re on chemotherapy, it decimates their immune system and one of the things that they have to be extremely careful of, is - because they’ve got no immune system - a basic common cold or flu can kill them. And this is what we’re seeing now in these jab recipients up and down the country.”

Reuters has already addressed claims comparing Omicron to the common cold (here). Comparisons of the effects that vaccines and chemotherapy have on the immune system are also not based in fact.

“COVID-19 vaccines do not weaken your immune system’s ability to respond to other infections so getting your jab will not make you more susceptible to colds or flu,” said Dr Doug Brown, chief executive of the British Society for Immunology.

“After COVID-19 vaccination, your immune system is just as able to fight off infections by cold or flu viruses, and it will be better prepared to protect you against COVID-19.”

Meanwhile, Professor Neil Mabbott, personal chair in immunopathology at the University of Edinburgh, said O’Looney’s claim was “very dangerous” and the reality of the shot’s effect was “quite the opposite”.

He told Reuters: “There have been several key studies showing how our immune response to the coronavirus vaccine is significantly strengthened by subsequent booster vaccinations… Our experience is showing that a third COVID-19 vaccine provides high levels of immunity, and this is the rationale for the current booster programme in the UK.”

Explaining why the common cold may be in wider circulation this year, he added: “Last winter we were in lockdown and social mixing, especially indoors, was very limited. This was very effective in limiting the spread of the coronavirus but also had other consequences. At the same time, it reduced our exposure to common cold viruses. Cases were very low indeed, meaning that the annual immunity top-up we normally received through virus infection did not occur.

“Unfortunately, our natural protection to the common cold will have declined to some degree, and this is reflected in the reports of increased severity of symptoms. But this is not at all due to impacts of the COVID-19 vaccination on our immune systems.”

A spokesperson for the University of Oxford COVID-19 Vaccine Team said: “There is no truth at all that vaccines weaken the immune system and that this causes death. This suggestion goes against every scientific principle of vaccination.”


False. COVID-19 vaccines do not weaken immune systems and leave recipients more susceptible to the common cold or flu.

This article was produced by the Reuters Fact Check team. Read more about our fact-checking work here.