GENEVA -- There is currently no evidence that
people who have recovered from COVID-19 and have antibodies are
protected from a second infection, the World Health Organization (WHO)
said in a daily situation report on Saturday.
Although many studies show that people who recovered from COVID-19
have antibodies to the novel coronavirus, also known as SARS-CoV-2, the
WHO noted, some of these people have very low levels of neutralizing
antibodies in their blood.
"As of April 24, 2020, no study has evaluated whether the presence of
antibodies to SARS-CoV-2 confers immunity to subsequent infection by
this virus in humans," stressed the UN health agency.
Some countries have suggested that the detection of antibodies to the
novel coronavirus could serve as the basis for an "immunity passport"
or "risk-free certificate", which would enable individuals to travel or
return to work, assuming that they are protected against re-infection.
However, there is still a lack of sufficient evidence for the
effectiveness of antibody-mediated immunity to guarantee the accuracy of
an "immunity passport" or "risk-free certificate, the WHO underlined,
warning that "the use of such certificates may therefore increase the
risks of continued transmission."
According to the UN agency, laboratory tests that detect antibodies
to SARS-CoV-2 in people, including rapid immunodiagnostic tests, need
further validation to determine their accuracy and reliability.