Asylum seekers showing symptoms of diphtheria will no longer be allowed leave processing centres, the immigration minister has announced.
Robert Jenrick said those with symptoms will either remain at the Manston migrant centre in Kent or travel to a "designated isolation centre".
He said it was "absolutely right that we are now vigilant" after the UK Health Security Agency confirmed an "increase" in cases of the highly contagious disease reported in asylum seekers arriving in the UK.
Between January 1 and November 25 2022 there were 50 cases involving migrants who had recently arrived in England, the UKHSA said.
There were two cases of "severe respiratory diphtheria requiring hospitalisation and treatment with diphtheria antitoxin and antibiotics".
Officials are also awaiting the post-mortem results of one individual who died and where a PCR test had confirmed the disease.
Updating MPs on Monday, Mr Jenrick insisted the risk to the wider population is "very low" due to a childhood immunisation programme, with over 90% of the public already vaccinated against diphtheria.
He said Home Office officials had now begun "robust screen processes" at Dover.
Mr Jenrick added: "I can confirm that of those who arrived at the facility this weekend 100% took up that vaccine offer."
"From today, no-one presenting with symptoms will progress into the asylum accommodation system.
"They will either remain at Manston, isolating for a short period, or they will travel to a designated isolation centre in secure transport where they will be treated until deemed medically fit."
"This is a well-practised protocol from Covid times".
But the Shadow Home Secretary Yvette Cooper criticised the absence of the Home Secretary Suella Braverman, asking: "What is she for?"
Responding to the statement from Mr Jenrick, Ms Cooper said: "The processes that he has just described now clearly are important, but why on earth were they not put in place many weeks ago?
"It took until November 11 after thousands of people had been held there for weeks for screening and vaccinations on diphtheria to be recommended for everyone passing through Manston."
She added: "The Health Secretary has said that 500 people have now been screened and vaccinated, what about the other several thousand people who have been in Manston? Wherever they now are in the country, have they been screened and vaccinated for diphtheria as well?
"If not, why on earth not? Because that was the public health recommendation nearly three weeks ago and that was already late."
Earlier, the Prime Minister's official spokesman told reporters: "We take the safety and welfare of people accommodated at these sites very seriously.
"We're working closely with the UK Health Security Agency and other health professionals and indeed councils to make sure all medical guidance and the robust protocols are followed and that we have contingency plans."
When asked the latest number of migrants at Manston, the spokesman did not know a figure but said the site was "significantly below capacity".
