The scientific evidence gathered so far does not provide certainty that a person who has contracted the coronavirus, has recovered and has generated antibodies is protected against a second infection, which leaves the idea of an “immunity passport” unsupported, he says. the World Health Organization (WHO).
The WHO thus escapes the claims of some governments that the detection of antibodies to SARS-CoV-2 (official name given to the new coronavirus) in a person could be enough to issue a “certificate” or “passport of immunity” indicating that you can no longer infect others.
In a guide for all its member states, which is the product of the analysis of the results of various studies, research and scientific articles, the WHO explains that most of them show that people who recover from the disease develop antibodies against the virus, but that in some cases its presence in the blood is very low.
Therefore, he highlights, “as of April 24, no study has evaluated whether the presence of anti-virus to SARS-CoV-2 confers immunity to subsequent infections in humans.”
“People who assume they are immune to a second infection because they have received a positive result (from the serology test) may ignore the sanitary measures, so the use of these certificates could increase the risk of transmission,” he warns.
Several countries expect their populations to develop “collective or” group immunity “as more and more people become contaminated and cured of the coronavirus.
However, the WHO considers that the preliminary results of serology tests carried out to detect how many people may have had contact with the virus indicate that its proportion is quite low, even in the most affected countries.
Furthermore, the WHO warns that these tests require further validation to determine their level of reliability and the accuracy of their results, in order to avoid mistakes and the consequent risks.
The first mistake they can induce is that a contaminated person is declared negative or, conversely, that someone who has not had the virus positive.
Likewise, the organization stresses that the tests must be able to distinguish between SARS-CoV-2 infections and those caused by any of the six known human coronaviruses.
Four of them cause the common flu, the fifth the MERS (Middle East Respiratory Syndrome) and the last the SARS.
“People infected with any of these viruses can produce antibodies that are confused with those produced in response to SARS-CoV-2,” the WHO said.