Doctor of molecular immunology Sirje Rüütel-Boudinot says that the people who have contracted the coronavirus develop very different immunities.
Rüütel-Boudinot told ETV show "Ringvaade" that she has been testing 500 people to get the cross-section of the population.
She explained that the test she is used to study the antibodies of COVID-19 and was developed in 2009, during a flu pandemic. The results of the tests will be published in June, when all the subjects have been tested.
Rüütel-Boudinot said that those who have recovered from COVID-19 in a difficult and slow pace have fewer antibodies left.
"I have a theory that if you have recovered from the virus slowly, you have fewer antibodie left. If you have a higher level of antibodies, you recover quite easily and will have experienced typical symptoms such as fever, cough, being sick for 10 days," the doctor said.
Rüütel-Boudinot added that people develop very different immunities. "Some people develop great levels of immunity and probably won´t get infected with the same form of the virus again. When I look at the presence of antibodies, it seems logical that they won´t [be re-infected]."
Of those who have been tested down to the present, about a half, those who had a tough recovery period, haven´t developed any antibodies, she said.
She added that people should get used to COVID-19, since it is not going anywhere.
Editor: Roberta Vaino