Why do measles outbreaks occur in middle and higher-income communities?

By: Robin Biellik, DrPH

Measles disease is easy to diagnose and measles vaccine is cheap and accessible. So why are we seeing continued and, in some cases, increasing measles incidence in middle- and higher-income communities around the world? In the past few years, despite a declining trend globally, reported measles incidence has increased in a number of middle- and higher-income countries in Western Europe, Southern Africa and, to a lesser extent, the Western Pacific[1].

In 2011, more measles cases were reported in the U.S. than in the previous 15 years. Most of these cases were related to exposure to measles imported from overseas.

Of particular concern is the growing number of major measles outbreaks in Europe, with the largest numbers of cases and deaths reported from Bulgaria, France, Germany, Romania, Spain and Switzerland[2],[3]. The causes of this phenomenon have been analyzed in depth and include, among others, lack of access due to social ostracism (Roma communities, immigrants), health system reforms that reduced resources for outreach services, vaccine refusal on the grounds of philosophical and religious beliefs, inadequate perceptions of the risks and benefit of vaccination among health care providers and the public, and anti-vaccine advocacy.

For some time, public health authorities have been aware of a growing trend among parents in middle- and higher-income communities of selectively or totally declining to vaccinate their infants against vaccine-preventable diseases. Many parents and their private physicians have not seen cases of vaccine-preventable disease for many years and believe they no longer pose any health threat. They are scared by reports of alleged vaccine-related adverse events they read in the media and on-line, and unaware that following scientific investigation most of these adverse events turn out to be unrelated to vaccine[4].

Anti-vaccine campaigners occasionally achieve national notoriety. Adverse publicity concerning DTP vaccine spread through high-income countries in the 1970s resulting subsequently in reduced vaccine uptake, a major pertussis outbreak, and many avoidable deaths[5]. This phenomenon occurred again in the past decade when falsified data linking measles vaccine and autism caused reduced vaccine uptake and a substantial accumulation of susceptible individuals, who now, as teenagers, have contracted measles during the recent outbreaks. Most recently, we witnessed how a US Congresswoman made unsubstantiated negative statements about HPV vaccine and declined to retract them.

The publication of anti-vaccine books, articles, websites, blogs and radio spots targeting well-educated parents has escalated enormously in recent years. In Western Europe and North America, anti-vaccine books on the shelves of bookstores’ health sections often outnumber evidence-based public health publications. Personally, I recall a poignant appeal by a WHO secretary during a meeting a couple of years ago who told us how, as a mother of young children living in France, she felt intimidated by the morning radio shows that relentlessly attack vaccination and brand parents who vaccinate their children as reckless and irresponsible.

But the public health community knows very little about the sources of these anti-vaccine books, articles, websites, blogs and radio spots, about who writes them, and who pays for them. Indeed, this blog article may attract more comments from anti-vaccine proponents than vaccine advocates.

Little systematic research has been conducted on the agenda of anti-vaccine activists, their methods and their funding. It will continue to be extremely difficult to counter this powerful lobby and its appeal to middle- and high-income parents until we learn a great deal more about where it comes from and how it operates.

About the author:

Dr. Robin Biellik has 40 years experience in public health, primarily in vaccine-preventable disease control, elimination and eradication. He has worked for UNHCR, UNICEF and spent 17 years with WHO in the Americas, Southeast Asia and Africa. Now retired and consulting, Dr Biellik continues his work in immunization for organizations including WHO, the London School for Hygiene and Tropical Medicine and the Bill and Melinda Gates Foundation. He also serves on several expert committees on immunization and is an invited reviewer for several medical journals.

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