Immunity passports: World Health Organisation has said there is no proof that recovered patients from coronavirus are shielded from the virus.
Some governments had suggested that the detection of antibodies to the SARS-CoV-2, the virus that causes COVID-19, could serve as the basis for an “immunity passport” or “risk-free certificate” that would enable individuals to travel or to return to work assuming that they are protected against re-infection.
“There is currently no evidence that people who have recovered from COVID-19 and have antibodies are protected from a second infection,” WHO said.
The Agency added: “At this point in the pandemic, there is not enough evidence about the effectiveness of antibody-mediated immunity to guarantee the accuracy of an “immunity passport” or “risk-free certificate.” People who assume that they are immune to a second infection because they have received a positive test result may ignore public health advice. The use of such certificates may therefore increase the risks of continued transmission.”
Reacting to the guidance from the WHO, Dr Jeremy Rossman, Honorary Senior Lecturer in Virology at the University of Kent, said: “The message is that we just don’t know enough at present to say if people that recover will be immune or not. We know that the virus causes a robust immune activation, we know that survivors do generate antibodies to the virus but we don’t yet know if it generates an immune memory that protects against re-infection, we don’t know what percentage of people will be protected and we don’t know how long this protection would last.”
A similar view has been expressed by Prof James Naismith, Rosalind Franklin Institute and University of Oxford, who said: “It seems certain that almost all people who have been infected will have complete immunity against re-infection for at least a short time.
“We know that for many coronaviruses, immunity weakens in many people over a few years, and for this reason some viruses infect and re-infect people. We do not (and cannot) know for sure how COVID-19 will behave.
“So-called ‘immunity passports’ for previously infected people are political inventions built around complex scientific concepts. Only a safe and effective vaccine, that I believe will come in the future, will deliver widespread immunity from infection. As things stand today there are two (and only two) proven ways to reduce the burden of infection at our disposal: strict social distancing; and test, trace, isolate with mild social distancing.”
He noted that relying on lockdown to curb the spread of the virus was becoming unbearable over the longer term. “Therefore, the UK and other countries should get on with setting up test, trace and isolate with a tolerable level of social distancing as quickly as possible. This means rapid testing, almost instant tracing that does not shred civil liberties and isolation that is effective yet compassionate,” Prof Naismith said. “We can play an important part: the more effectively we practise social distancing at the moment, the faster the infections will drop and the sooner that test, trace, isolate will become viable.”