The scariest thing about measles is probably not the related deaths, of which there have been two already this winter, the first in the United States in a decade. It may not even be the one-in-10,000 risk of irreversible lifelong paralysis, known as subacute sclerosing panencephalitis. Instead, it’s the much more common effect the virus can have on what’s called immunological memory — creating an immune amnesia that can devastate your ability to fight off future infections.
During the pandemic, when some worried Americans panicked over signs that Covid could damage immune response, they were mocked by minimizers for believing the novel virus was effectively airborne AIDS. The hyperbole applies more appropriately to measles: Before mass vaccination, the rapaciously infectious virus so ravaged the immune systems of children that despite its relatively low direct mortality rate, the virus could have been implicated in as many as half of all childhood deaths from infectious diseases, including pneumonia, sepsis and meningitis.
