Prime Minister Boris Johnson has gone into self-isolation after coming into contact with an MP who has since tested positive for coronavirus.
Mr Johnson contracted Covid-19 earlier this year and spent a significant amount of time in hospital and in recovery.
This morning MrJohnson tweeted that he is “in good health and have no symptoms” after being instructed to self-isolate.
In a video posted to Twitter he said: “Hi folks, the good news is that NHS Test and Trace is working ever-more efficiently, but the bad news is that they’ve pinged me and I’ve got to self isolate because someone I was in contact with a few days ago has developed Covid.
“It doesn’t matter that we were all doing social distancing, it doesn’t matter that I’m fit as a butcher’s dog, feel great – so many people do in my circumstances.
“And actually it doesn’t matter that I’ve had the disease and I’m bursting with antibodies. We’ve got to interrupt the spread of the disease and one of the ways we can do that now is by self isolating for 14 days when contacted by Test and Trace.”
Danny Altmann, professor of immunology at Imperial College London, said the rules that mean Boris Johnson has to self-isolate “probably are sensible”.
He told BBC Radio 4’s Today programme there have been more than 25 confirmed cases of Covid-19 reinfection globally, but added: “I think most of us think the rate of reinfection is quite a lot higher than that, but not enormous.”
Prof Altmann said: “I think my bottom line is not to be alarmist because whatever the risk is, it is low. My sense from some of our data and other people’s data is that it’s the people who’ve made the poorest and most negligible antibody response the first time round who are most at risk of reinfection.
“So that’s maybe 10% of everybody out there who’s been infected in the first wave.”
He added: “If we’ve learnt anything since the beginning of 2020, it’s that this is an incredibly infectious and scary virus and you can’t take it too seriously.
“So all the things that we know about – using masks, well-ventilated work spaces – following those rules really matter. And if you’ve got one take-home message from a reinfection discussion, it’s not to be blase because you’ve had it or you think you’ve had it.”