Measles incidence tripled, then fell by three quarters in a year

Nearly tripled over five years, then fell by three quarters in one.

**The rise was primarily because of large outbreaks in Pakistan, Somalia and
Yemen.**

What those three have in common

Not a vaccine problem, not a health belief problem — **war, state collapse, and
displacement.** Yemen was in a civil war; Somalia had been without functioning
central government for decades; Pakistan has regions where vaccinators have
been attacked and cannot work.

Measles is the most contagious disease there is, and it finds any population
where routine immunisation has lapsed. Where a health system stops, measles
resumes within a couple of birth cohorts.

That also explains the 2019 fall. A regional figure dominated by three
outbreaks drops sharply when those outbreaks end — which is not the same as
the underlying coverage improving.

The background

During 2008–2012, first-dose measles vaccine coverage in the region was 83%,
and reported cases roughly tripled, from 12,196 to 36,456. Eighty-three per
cent sounds high and is not: measles needs around 95% with two doses to stop
circulating, so 83% with one dose leaves a large susceptible population
accumulating every year.

What elimination would take

**Increase MCV1 and MCV2 coverage, conduct high-quality supplementary
immunization activities, and reach populations at high risk for not accessing
immunization services or living in areas with civil strife.**

Three requirements, and the third is not a health intervention. It is the one
that decides whether the other two can happen, and it is outside the control of
everyone who would carry them out.

Source: Centers for Disease Control and Prevention, MMWR.