Speaking on his Sunday programme after a week off, Marr told viewers that “he had a bit of Covid last week, despite being double jabbed, and very nasty it was too.” Marr described his symptoms like those of a “summer cold,” and asked guest Professor Peter Horby, a government adviser on the coronavirus, whether he was “just unlucky” to catch the virus after being fully vaccinated.

“I think you were,” Horby replied. Vaccines, he said, “are actually remarkably effective at preventing hospitalisations and deaths. They are less effective at preventing infection.”

“So, although you were sick, you weren’t hospitalised and there wasn’t any fatality, and that is probably because of the vaccination.”

Marr is 61 years old and was vaccinated earlier this spring. He suggested on Sunday that he may have caught the virus while covering the G7 summit in Cornwall earlier this month.

Marr’s case is one of many around the world in which fully vaccinated people have managed to catch the virus regardless. Two American guests aboard a “fully vaccinated” cruise ship made headlines when they tested positive for Covid-19 earlier this month, and a study back in April found that among fully vaccinated US workers, around 1% still got infected. Altogether in the US, more than 4,100 people have been hospitalised or died after catching Covid-19 post-vaccination, according to data released last week by the Centers for Disease Control and Prevention (CDC). No comparable data from the UK is readily available, but the country has one of the world’s highest rates of vaccination, and has seen new cases tick steadily upwards since the beginning of summer.

Though vaccines are regarded – at least in the public consciousness – as a ticket to safety and normality after a year of outbreaks and lockdowns, health officials are still recommending that social distancing guidelines be adhered to.

“People cannot feel safe just because they had the two doses. They still need to protect themselves,” Dr. Mariangela Simao, World Health Organisation assistant director-general for access to medicines and health products, said during a briefing on Friday.

“People need to continue to use masks consistently, be in ventilated spaces, hand hygiene… the physical distance, avoid crowding. This still continues to be extremely important, even if you’re vaccinated when you have a community transmission ongoing,” Simao added.

In the UK, that community transmission has been driven by the Delta variant of the coronavirus, first detected in India. This variant, which is thought to spread more rapidly than others, now accounts for 95% of cases sequenced in the UK, per data from Public Health England.