People should not try and get infected at so-called Covid parties, global health leaders have warned.

It comes after images and videos appeared on social media, purportedly of people purposefully trying to catch Covid at a time convenient to them.

The World Health Organisation (WHO)’s technical lead for Covid-19, Dr Maria Van Kerkhove, warned of the threat of long Covid and the possibility of passing the virus on to the vulnerable.

She told a social media briefing: “I don’t know if you’ve seen on social media, or if you’ve heard people say, ‘Well, why bother? Omicron is everywhere and I might as well just get infected now’.

“That’s a very dangerous question and it’s one worth answering.

“The reason we don’t want this virus to circulate is number one, your chance of developing severe disease is real.  If you have underlying conditions, are of an older age, if you’ve not received a vaccination, you could die.

“And that’s what we want to prevent and we can prevent that.

“But you can also pass the virus to somebody else who is more vulnerable.

“And we are just learning about post-Covid condition – long Covid.

“We don’t know the implications of Omicron, which replicates in the upper respiratory tract as opposed to the lower respiratory tract and if that has any implication on your chances of developing longer term effects.

“So that’s reason enough not to get infected.

“But there are so many unknowns.”

Dr Van Kerkhove added: “I’ve heard some very scary stories about, you know, parties of people and trying to get infected. Please, that is very unsafe.

“We are working very hard with all of our partners around the world to give you advice to avoid exposure, to reduce your chance of getting infected, to reduce your chance of passing the virus onward.

“This is critical right now. It is not the time to retreat. It is not the time to give up, because we have these tools.

“We are not talking about shutting down societies. What we’re talking about is increasing coverage of vaccine, making sure people have access, as well as simple measures to keep yourself safe, distancing, working from home if you can, access to testing, wearing a well-fitted mask over your nose and mouth, avoiding crowds, improving ventilation.

“So please do what you can to avoid infection.”

Dr Van Kerkhove said the Omicron variant is “not a mild disease”.

“Please treat this virus as seriously as it needs to be treated,” she said.

“Not to scare anybody, but the narrative that it’s a common cold is not true, a narrative that it is ‘just mild’ is not true.

“So we have to really fight against it. It’s not the time to give up. We have tools at hand that can keep people safe.”

Meanwhile Dr Mike Ryan, executive director of the WHO’s emergencies programme, urged people to get their booster when offered, saying the acceptance of vaccination is not a “moral grey area”.

It comes as WHO said more than three billion people globally are yet to receive a single vaccine.

He said: “Please remember this isn’t an individual moral issue. If you’re offered a vaccine, take the vaccine. If you’re offered a second vaccine, take the vaccine. If you’re offered a booster, take the booster.

“No individual on this planet should feel they’re the ones in a moral grey zone.“If you’re offered the vaccine, take it.”

Dr Ryan said countries could do more to ensure vaccine equity, adding: “If we can’t address the simple issue of the equity of every individual on the planet having access to a protective course of vaccine against a pandemic – if we can’t do that – how in God’s name are we likely to deal with the bigger issues of climate justice and social justice that we face in the world?”