I posted a chart, last week, showing the spectacular reduction in measles cases and measles deaths following the introduction of measles vaccination in the mid-1960s. Anti-vaccine loons often dismiss such charts by claiming that they only demonstrate the effect of sanitation, or something — as if sanitation was only introduced into the US in 1965. In any case, here are some more data, showing the effect of measles vaccination at very different times, in very different countries.
Finland had a problem with measles, as well as mumps and rubella, in the 1970s. The vaccine coverage was about 70%.1 It’s important to note that for measles, which is probably the most contagious disease known to man, very high vaccine coverage (probably over 90%) is necessary to protect against outbreaks — this has been shown by modeling as well as by experience.
So the 70% coverage was far too low to offer protection against outbreaks, and there were an average of about 100 deaths per year in the 5 million or so Finnish population. (That would extrapolate to, what, about 6000 deaths per year in the US, to put this in context with the previous chart.) In 1982, a national vaccination program was put in place for measles, and after 1986 (when an extra push was put in place) coverage increased to 97%.2
Here’s the chart showing measles incidence in Finland. Note that this is a log scale, not a linear scale, on the Y axis. Also pay attention to the dates: Remember, 1982 national vaccination — 1986, final push.
OK, that’s Finland in the 1980s – a rich Scandinavian country, with excellent sanitation and so forth. Here’s a very different situation: three poor African countries in the early 21st century. Measles vaccine coverage in Burkina Fasso, Mali, and Togo was very low at the turn of the century, between 33% to 69%3. In Dec ’01 to Jan ’02, a series of nation-wide projects boosted vaccine coverage among children to over 95% in each country. Here’s the effect on cases and deaths:
It would be hard to find more different circumstances than between Finland and Burkina Fasso; yet in each case, increasing measles vaccine coverage to the proper level vastly reduced measles cases and deaths.
- Peltola H, Heinonen OP, Valle M, Paunio M, Virtanen M, Karanko V, Cantell K (1994) The elimination of indigenous measles, mumps, and rubella from Finland by a 12-year, two-dose vaccination program. N Engl J Med 331:1397–1402.[↩]
- The paper I cite also gives the rate of complications from the vaccine — very low, though not non-existent, as with the US experience.[↩]
- MMWR Weekly. January 23, 2004 / 53(02);28-30. Measles Mortality Reduction — West Africa, 1996–2002[↩]