ABOVE: Post-mortem thoracic lymph nodes of a COVID-19 patient (left) lack clusters of Bcl-6–bearing T cells and B cells (stained in yellow), which populate the germinal centers and are clearly visible in a healthy control patient who died of other causes (right). COVID-19 patient lymph nodes also show different distributions of CD3+ T cells (pink) and CD19+ T cells (turquoise).
NAOKI KANEKO AND SHIV PILLAI, RAGON INSTITUTE OF MASSACHUSETTS GENERAL HOSPITAL, MIT AND HARVARD
When our immune system encounters a new virus—say, SARS-CoV-2—for the first time, some of our plasmablast B cells will release a first flush of antibodies that can stick to and even neutralize the virus. But those first antibodies are short-lived, typically don’t stick very strongly, and the cells that produce them don’t last longer than a few weeks.
As reinforcement, the immune system has a program in place to create long-lived plasma cells that secrete even better, ...
