University’s Medical School scientists in St. Louis have proven that after the soft form COVID-19 there are immune cells that can produce antibodies against coronavirus throughout life. Such long-term protection makes the probability of re-infection very low. The results of scientific work are published in the Nature magazine.
77 people took part in the study, which handed over three-month intervals a month after infection. Most volunteers had light cases of COVID-19, and only six were hospitalized. Bone marrow samples were taken from 19 patients 7-8 months after infection. Four months later, five of them passed the second sample of bone marrow.
As expected, the levels of antibodies in the blood of the COVID-19 participants quickly fell in the first few months after infection, and then their level was leveled. Although information appeared in the media that the amount of antibodies decreases after infection, the latter is not associated with a weaker immunity, since cells can be able to produce antibodies to SARS-COV-2. Scientists have found that these cells, called plasma, are present in the blood of people 11 months after infection. Cells migrate into a bone marrow, where antibodies in blood constantly isolated, providing protection against a new infection.
Researchers suggested that people who suffered asymptomatic COVID-19 can also have long-term immunity. However, it is still to be investigated whether those who suffered from more severe symptoms to be protected from re-infection with coronavirus.