Cases of Covid-19 in double-vaccinated people are continuing to rise, the latest data from the ZOE Covid study suggests.
It follows anecdotal reports from GPs that they are seeing increasing numbers of patients testing positive despite being double jabbed but a general reluctance to get tested.
A weekly update from the ZOE study at King’s College London, said there were currently 15,537 new daily symptomatic cases in partly or fully vaccinated people, an increase of 40% from 11,084 new cases last week.
By contrast in unvaccinated people in the UK there are currently an average of 17,581 new daily PCR-confirmed symptomatic cases of Covid, according to the ZOE figures, a drop of 22% from the week before.
It suggests the number of new cases in the vaccinated population is set to overtake the unvaccinated in the coming days, the team noted.
Data from Public Health England shows that there have been 10,834 people hospitalised with the Delta variant after being double-vaccinated out of a total of 123,620 total cases.
Analysis of routine testing data in the UK up to the 13th June suggests that a single vaccine dose is 35% effective against symptomatic disease caused by the Delta variant but 80% effective against hospitalisation and for two doses that rises to 79% and 96% respectively.
In general, the pattern shows that the vaccines work less well against getting symptoms with the Delta variant compared to the Alpha but just as well at preventing a hospital admission. There has been some debate about vaccine effectiveness in immunosuppressed patients.
ZOE study leader Professor Tim Spector said overall the data suggested incidence rates were starting to plateau.
But he added: ‘In the UK, new cases in vaccinated people are still going up and will soon outpace unvaccinated cases.
‘This is probably because we’re running out of unvaccinated susceptible people to infect as more and more people get the vaccine.
‘Whilst the figures look worrying, it’s important to highlight that vaccines have massively reduced severe infections and post-vaccination Covid is a much milder disease for most people. The main concern is now the risk of long Covid.’
Dr Richard Cook, a GP in Sussex, said: ‘We are speaking to lots of Covid positive patients who have had two vaccines.
‘Anecdotally they do not seem to be getting too unwell, and I’m not aware of any of ours being in hospital.
He added: ‘I think there is a general reluctance among many patients to get tested and some are quite shocked when I suggest it. Many are using lateral flow tests even if they are symptomatic and I think a public health message being pushed out would be really helpful.’
Dr Lis Galloway, a GP in Surrey, said: ‘We have seen several cases of patients with Covid over the last two weeks in those who have had been fully vaccinated, including one of our own staff.
‘Fortunately most have been willing to test when it’s been advised. All have been really quite surprised with the result and some had admitted to being a little less strict in sticking to the rules in the timeframe between symptom onset and test result.’