Adverts by private clinics and test centres claiming antibody tests could show whether a person is immune to Covid-19 have been banned by the UK's advertising watchdog.
The adverts by Corona Test Centre and London Vaccination Clinic were ruled misleading by the Advertising Standards Authority .
Meanwhile, an advert by Solihull Health Check Clinic said their antibody test was '100 per cent accurate' in telling a patient whether they had contracted coronavirus - a claim which was 'not substantiated by evidence'.
The watchdog fast-tracked the cases as part of its focus on 'tackling ads that exploit health related anxieties during the pandemic'.
A direct email to consumers by the London Vaccination Clinic, run by 360 Health Ltd, on May 27 told recipients who were thinking about getting back to work that a blood test could tell them within two days 'whether you have potential antibodies to Covid-19'
A paid-for Facebook advert for Corona Test Centre London - a test provider owned by XMedical Ltd - showed the message: 'We are on a mission to safely get you back to your friends and back to work'
Meanwhile, an advert by Solihull Health Check Clinic said their antibody test was '100 per cent accurate' in telling a patient whether they had contracted coronavirus - a claim which was 'not substantiated by evidence'
A paid-for Facebook advert for Corona Test Centre London - a test provider owned by XMedical Ltd - featured an image of several socially-distanced people wearing overalls and facemasks.
It showed the message: 'We are on a mission to safely get you back to your friends and back to work'.
A page on its website, as seen in May this year, also included the claim that 'Antibody testing will tell you if you've had the virus and developed an immune response'.
XMedical Ltd removed the ad from Facebook, Instagram and Google, but argued its website was not an ad 'because it was their home page and their consent page'.
What are antibodies and does having them mean you're immune to Covid?
Antibodies are substances produced by the immune system which store memories of how to fight off a specific virus.
They can only be created if the body is exposed to the virus by getting infected for real, or through a vaccine or other type of specialist immune therapy.
Generally speaking, antibodies produce immunity to a virus because they are redeployed if it enters the body for a second time, defeating the bug faster than it can take hold and cause an illness.
An antibody test, which involves analysis of someone's blood sample, has two purposes: to reveal whether an individual has been infected in the past and may therefore be protected against the virus, and to count those people.
Knowing you are immune to a virus can affect how you act in the future.
Someone may need to protect themselves less if they know they have been infected, for example, or medical staff may be able to return to work in the knowledge they are not at risk.
But it is not yet known whether people actually develop immunity to Covid-19.
The NHS states the tests does not reveal if a patient is 'immune to coronavirus' or if they 'cannot spread the virus to other people'.
It said thousands of people, including NHS professionals, visited its centre.
According to its website, the antibody and antigen tests cost £120 each, while its Fit to Fly and PCR tests go for between £165-175.
The ASA claimed the statement in the Facebook ad would be interpreted by readers to mean the tests 'were capable of indicating whether or not someone could safely return to work and to social gatherings without fear of contracting or passing on the virus'.
It said the company's website page 'marketed XMedical's antibody testing services' and was therefore considered an ad within the ASA's remit.
It ruled the ads misleading after it found no information in either which explained that a positive antibody result did not mean that a person was immune.
In its ruling on Wednesday, the ASA said: 'We considered that consumers were likely to understand from the ads that a positive antibody test would show that they were immune to Covid-19, and would enable them to get back to work and other normal activities without the risk of contracting the virus again or transmitting it to others.'
The watchdog found that, as of July 13, Government guidance stated there was no strong evidence yet to suggest that those who had contracted the virus and produced antibodies were immune.
The ASA also banned an ad which appeared on the Solihull Health Check Clinic website, which featured text stating it is offering tests with 100 per cent accurate results within 24 hours, with text underneath stating 'Public Health England and Government Approved'.
The ad, as seen on July 2, also claimed that its test could indicate whether a person has developed an 'immune response' to coronavirus.
The West Midlands-based clinic said it only used the Abbott antibody test which has been found to demonstrate 100 per cent sensitivity and 97.5 per cent specificity.
However, the ASA said: 'We considered that neither the sensitivity rate, nor the specificity rate, when used in isolation, were likely to conform with consumers' likely understanding of "100 per cent accuracy" as presented in the ad.'
It said the ad was misleading as it considered the claim '100 per cent accurate results' as an indication that the antibody test would detect - without fail and in all circumstances - whether or not a patient had contracted Covid-19, which was not substantiated by evidence.
The ad which appeared on the Solihull Health Check Clinic website, as seen on July 2, claimed that its test could indicate whether a person has developed an 'immune response' to coronavirus
Meanwhile, a direct email to consumers by the London Vaccination Clinic, run by 360 Health Ltd, on May 27 told recipients who were thinking about getting back to work that a blood test could tell them within two days 'whether you have potential antibodies to Covid-19'.
The ASA said it was likely consumers would understand from the ad that a positive antibody test would show that they were immune to Covid-19, and would enable them to get back to work and other normal activities without the risk of contracting or transmitting the virus.
It continued: 'We noted that the qualification "potential" was used in reference to immunity, but we did not consider that conditional language counteracted the impression of efficacy in this context.
'Further, 'long-term immunity' implied that the test would enable people to get back to normal life, rather than just detecting Covid-19 antibodies.'
The ASA said the ads must not appear again in their current form.
The London Vaccination Clinic (file image) sent an email promising to tell patients 'whether you have potential antibodies to Covid-19'
The rulings come as the debate around immunity continues, after researchers in the US found a 25-year-old man was infected with Covid-19 on two separate occasions.
The study published in the Lancet Infectious Diseases journal said findings indicate previous exposure to the virus may not guarantee total immunity.
But a defiant Donald Trump told a packed rally in Florida, his first campaign since contracting Covid-19, that he felt well and was glad he no longer needed to be concerned about infection because he was now 'immune'.
