“Immune sterilization does not occur very often — it is not standard,” said Alessand Rossette, an immunologist and co-leader of the study at the Lahora Institute of Immunology.
In many cases, people are infected twice with a particular pathogen, and the immune system recognizes the intruder and quickly eliminates the infection. Coronaviruses, in particular, are slow to harm and give the immune system enough time to get up and running.
“Not only is it asymptomatic, it can end so quickly that it is not infectious,” Dr. Sette said.
Dr. Sette and his colleagues recruited 185 men and women aged 19 to 81 who recovered from Covid-19. The majority showed mild symptoms that did not require hospitalization. Most provided only one blood sample, but 38 provided multiple samples over the months.
The team tracked four elements of the immune system. Antibodies, B cells that make more antibodies as needed. Two types of T cells that kill other infected cells. The idea was to build an image of the immune response over time by examining its components.
“If you look at just one, you can miss the big picture,” Dr. Crotti said.
He and his colleagues found that the antibodies were durable and slightly reduced 6-8 months after infection, although there was a 200-fold difference in levels between participants. T cells showed a slight slow decay in the body, but the number of B cells increased. This is an unexpected discovery that researchers cannot fully explain.
According to experts, this study is the first to graph the immune response to the virus in this detail. “Sure, there is no precedent here,” said Dr. Gommerman. “I think we’re learning some of the dynamics of these populations for the first time over time.”
Immunity against coronavirus last May, tips for new data
Source link Immunity against coronavirus last May, tips for new data