Five things everyone should know about measles, particularly now, with a measles outbreak in Texas and a new head of Health and Human Services who doesn’t approve of vaccines.

5) Measles is one of the most contagious viruses.
– 90% of unprotected close contacts will also get measles.

4) Measles has one of the most effective vaccines.
– 97% effective with 2 doses, 93% effective with 1 dose.

3) Measles has no treatment, only prevention.
There is no cure or treatment for measles beyond general care to alleviate symptoms, and specific care to address complications (such as antibiotics for pneumonia).

2) Measles can be deadly.
– One in five unvaccinated people with measles will be hospitalized.
– One to three in a thousand will die, “even with the best care”.
– Measles can be followed months to years later by an extremely rare but overwhelmingly fatal brain inflammation called Subacute sclerosing panencephalitis (SSPE).

1) Immune Amnesia: Measles wipes out ALL previously acquired immunity to other infectious diseases.
It turns out the body’s receptors for measles are not (or not only?) in the airway, as with other respiratory diseases, but in the immune system. Where it replaces all other memory cells with measles memory cells. And you have to start all over again.

Sources
General:
– from the World Health Organization
– from the Centers for Disease Control (at time of this post, the last update is 4/18/24)
– from the California Department of Public Health (this one is a pdf)
– from the National Foundation for Infectious Diseases

Vaccines:
– from the Centers for Disease Control (at time of this post, the last update is 1/17/25)

Subacute sclerosing panencephalitis (SSPE):
– from Wikipedia

Immune Amnesia:
– in story form from the BBC, Measles: The race to understand ‘immune amnesia’ (this is where I first read about it in 2021, updated in 2024)
– from the American Society for Microbiology (but easily readable, not a research article)

Further reading (fiction):
The measles outbreak in California in 2014-2015 prompted me to collect some story recommendations to remind people what life was like before vaccination and other medical advances eliminated many childhood diseases.