Recovering from Covid offers just as good protection as getting two doses of any vaccine, official figures suggest.
An Office for National Statistics’ (ONS) report published today found unvaccinated Britons who catch the Delta variant are around 71 per cent less likely to test positive for a second time.
The ONS said there was ‘no evidence’ vaccines offered more immunity than catching Covid itself, despite a number of other studies showing the opposite.
The findings are based on more than 8,000 positive tests across Britain between May and August, when the Delta variant became dominant.
Scientists are still trying to untangle exactly how long naturally-acquired and vaccine immunity lasts.
Protection from the jabs appears to dip at around five months, which is why Britons over the age of 50 are being offered booster doses this autumn. But the duration of natural immunity remains somewhat of a mystery, made more complicated by the rise of new variants.
The above graph shows the risk of catching the virus by vaccination status and previous infection. It reveals that there is no difference in risk between the double-vaccinated and those who have previously recovered from infection (shown by the blue lines, which represent the variation between each result, overlapping)
When broken down by vaccine, Pfizer’s jab was slightly more effective than AstraZeneca’s
The ONS looked at 8,306 positive PCR results between May 17 and August 14.
Samples were collected from unvaccinated, fully vaccinated and double-jabbed volunteers, some who had previously had the virus already.
Using a statistical analysis, the report found those who were double-jabbed had a reduced the risk of testing positive by between 64 and 70 per cent, giving the headline figure of 67 per cent.
Covid booster jab uptake ‘is too slow to stop overcrowded hospitals this winter’ as immunity wanes
The uptake of Covid booster jabs may be too slow to prevent hospitals from becoming overcrowded this winter, experts have warned as cases soar by 30 per cent.
One month into the booster programme, only half of eligible over-80s have received a third dose, despite being at heightened risk, NHS figures suggest. Of the 2.2 million who had a second jab more than six months ago, fewer than 1.2 million have had the booster.
The number of people aged 65 to 84 admitted to hospital has risen 19 per cent in the past week, with admissions up 8 per cent among people over 85.
Yesterday the UK reported a 30% weekly increase of coronavirus cases to 45,140 within 28 days of a positive test – the highest total since July – but deaths plummeted by nearly two-thirds from 148 to 57 in the space of a week.
In Scotland, which still has mask rules, cases per capita are higher despite the tougher restrictions.
It comes after testing operations at Immensa Health Clinic Ltd’s laboratory in Wolverhampton which mainly served the south west were suspended because of faulty tests.
Health officials revealed that 43,000 people in south west England may have been wrongly told they don’t have the coronavirus because of problems processing PCR test results at the lab.
The Health Security Agency said a lab in Wolverhampton was suspended from processing the swabs after reports of false negatives. The faulty results are among tests processed at the Immensa Health Clinic Lab between early September and this week.
The issue was uncovered after some people who were positive for COVID-19 when they took rapid tests went on to show up as negative on more accurate PCR tests.
Cases in the south west have now doubled over a four-day period – from 2,334 reported on October 9 to 5,681 on October 12.
And it comes amid fears Britain will start to see a possible waning of protection against Covid in those who got their vaccines the earliest, as happened in Israel earlier this year.
In people who were unvaccinated but previously positive, the risk was cut by between 65 per cent to 77 per cent.
The overlap in confidence intervals meant that there was no statistical difference between the results.
Writing in the report, the ONS said: ‘There was no evidence that the reduction in risk of infection from two vaccine doses differed from that of previous natural infection.’
The ONS found that two doses of Pfizer’s jab offered slightly higher protection against infection than two of AstraZeneca.
But the ONS said it was not statistically significant and added that any slight difference may be due to the fact Pfizer’s was rolled out to the masses slightly later than AstraZeneca’s.
The report does not look at the negative effects of catching the virus, including long Covid, which blights a significant number of adult sufferers.
But critics of the Government’s decision to vaccinate healthy school pupils as young as 12 have argued that natural immunity is better for children because it removes the small risk of side effects from the jabs.
There is a small one in 10,000 risk of myocarditis — an extremely rare form of heart inflammation that is not necessarily serious — in children.
It is slightly more prevalent in boys but doctors say most cases are treatable. But the long term implications of the condition are not yet fully understood. Whereas, the risk of being admitted to ICU with Covid in healthy teens is around one in 500,000.
Data from the ONS report also confirmed that the vaccines are less likely to stop an infection now than when the Alpha variant was dominant, between December 2020 and May this year.
At that time, double-vaccination cut the risk of testing positive for the virus by 79 per cent. For comparison, among those who had beat Alpha, the risk was reduced by 65 per cent.
Sarah Crofts, the head of analysis for the Covid infection survey, said in a blog post that the drop in vaccine protection between the two recording periods was likely down to waning of vaccine immunity.
She said: ‘The most recent data… includes results from participants who had experienced a longer average time period since their second Covid vaccination.
‘If there is any change in vaccine effectiveness over time (such as vaccines wearing off) then it is more likely to have been identified in the latest analysis.’
She added that small sample sizes may also have influenced the figures.
There were just 99 people in the group who had recovered from the virus between May and August, compared to almost 4,000 among the double-jabbed.
To be counted as recovered from the virus, someone had to have not received a single dose of the Covid vaccine.
‘Additionally, when we estimate the risk of infection among vaccinated people compared to unvaccinated people, we need test results from each group of people.
‘Over time, more people have received vaccinations and so there are smaller numbers of unvaccinated people to compare with.’
Department of Health data suggests some 45.3million people — or more than nine in ten adults — have already received two doses of the Covid vaccine.
And almost half of over-50s had got their third booster dose by mid-September, data showed, about a month after they were offered to the age group.
Some 3.1million had already received this shot by Sept 16, out of the estimated 6.5million who are eligible.
The true extent of immunity against the coronavirus remains unknown. It has been made more difficult to untangle by a series of conflicting studies.
A study in Israel published last month found that unvaccinated people with natural immunity were 13 times less likely to catch Covid than double-jabbed people who had never been exposed to the virus before.
However, experts at King’s College London found that people with two vaccines enjoy up to 80 per cent protection against infection compared to just 65 per cent in the natural immunity group.