The World Health Organisation’s interactive map of global immunisation rates for measles gives a fascinating view of how the numbers have changed for individual countries and regions over the period 1980 to 2015.
The chart, published last year, looks at the first dose of measles (MCV1) immunisation coverage among 1-year-olds. It covers every country, as well as select regions, with users being able to review results by a variety of factors. And the variations are significant.
The lowest rates for 2015 are all in central Africa, with South Sudan the lowest on 20%. This might not be surprising considering the civil wars and desperate refugee issues that have run on-and-off in the country between 1955 and 2005. But that view is contradicted by the fact that South Sudan had an immunisation rate of 90% in 2010. While this high rate did not last, a steady growth from 1999 indicates a major and effective drive for immunisation, followed by a dramatic and rapid dive in recent years.
What also puts Sudan’s highest point in context is that it is almost identical with the figure for Australia in 2015 (91%). Australia stayed in the high 60% range during the late 1980s, gradually rising to the mid to high-80% during the 1990s and then a sudden dip to 82% in 1998. This may very well have been in response to the widely publicised reports on a claimed link between the measles-mumps-rubella (MMR) vaccine and autism, as presented in a paper co-authored by disgraced British gastroenterologist Andrew Wakefield and published in The Lancet in February 1998. (The article was retracted 12 years later.)
By 2002, measles vaccination in Australia for 1-year-olds had risen to 94% (the highest it has ever achieved), but in the last few years this has dropped back down to 91%, again perhaps due to scare mongering by the anti-vaccination movement.
The UK suffered a similar decline following the publication of the Wakefield paper. The WHO figures show a decline from a high of 92% in 1996 to a low of 81% in 2004. This decline led to a considerable resurgence of cases of measles in the UK. The rate has now rebounded, steadily increasing to 95% in 2015.
Other nations in our region show similar changes, with New Zealand suffering a dramatic and almost instant decline between 1997, when it had a highly successful rate of 99%, to a very low 81% the following year. This extremely worrying situation is unlikely to be due to a one-off statistical anomaly, as rates in New Zealand hovered around that figure for the next eight years. It has recently increased to 93% in 2015.
Fiji has shown quite stunning increases, from 32% in 1981 to 94% in 2018 (with a momentary blip of 0% in 1982). This is no doubt largely due to a primary health care program initiated in the late 70s. Ironically, this campaign has been in part supported by the Australian government, with the result that the Fiji level is now above that of Australia.
Some positive figures may be the result of governmental boosting – wishlists and propaganda. But based on what we have, the countries with the highest measles immunisation rates for 1-year-olds in 2015 may surprise. Considering national stereotyping, it is not surprising that Finland (97%) and Sweden (98%) figure prominently. What may be more surprising is that Russia, Iran and Vietnam (all with 98%) are among the list. But what are the top rated countries? According to the figures released, which may need to be taken with a grain of salt, those with 99% coverage include China, Brazil, Uzbekistan, Kazakhstan, Turkmenistan, and Kyrgyzstan.
Overall, the interactive map is an impressive and useful source of data that can keep a reader occupied for hours. Finding the reasons for increases and decreases in immunisation rates will require follow-up on a case-by-case, country-by-country, and region-by-region basis, but factors that are no doubt involved are improved procedures for mass immunisation, better communication of benefits via governments and the media, national geopolitical circumstances, and the negative impacts of anti-vaccination scare tactics.