New Delhi: Recovery from Coronavirus is no certificate of immunity from re-infection, the World Health Organisation said on Saturday in a new scientific paper for the next phase of Covid-19 response, as several countries issue immunity passports to the recovered patients to get back to work to support the staggering economies.

The WHO warned on Saturday that there was still no evidence that people who test positive for the new coronavirus and recover are immunised and protected against reinfection. "There is currently no evidence that people who have recovered from Covid-19 and have antibodies are protected from a second infection," WHO said in a statement. "People who assume that they are immune to a second infection because they have received a positive test result may ignore public health advice," it said.

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 on Saturday, some of these people have very low levels of neutralizing antibodies in their blood, reported Xinhua news agency.

However, in a later tweet, the body clarified that most people who are infected with Covid-19 will develop an antibody response that will provide some level of protection.

It said: “Earlier today we tweeted about a new WHO scientific brief on "immunity passports". The thread caused some concern & we would like to clarify: We expect that most people who are infected with #COVID19 will develop an antibody response that will provide some level of protection.”

 Image: Twitter/ WHO

The warning came as some governments study measures such as "immunity passports" or documents for those who have recovered as one way to get people back to work after weeks of economic shutdown. The United Nations has joined world leaders to speed up development of a vaccine, but effective treatments for COVID-19, the disease caused by coronavirus, are still far off.