MMR Vaccine Controversy - Disease Outbreaks

Disease Outbreaks

Further information: Measles outbreaks in the 2000s and Mumps outbreaks in the 2000s

After the controversy began, the MMR vaccination compliance dropped sharply in the United Kingdom, from 92% in 1996 to 84% in 2002. In some parts of London, it was as low as 61% in 2003, far below the rate needed to avoid an epidemic of measles. By 2006 coverage for MMR in the UK at 24 months was 85%, lower than the about 94% coverage for other vaccines.

After vaccination rates dropped, the incidence of two of the three diseases increased greatly in the UK. In 1998 there were 56 confirmed cases of measles in the UK; in 2006 there were 449 in the first five months of the year, with the first death since 1992; cases occurred in inadequately vaccinated children. Mumps cases began rising in 1999 after years of very few cases, and by 2005 the United Kingdom was in a mumps epidemic with almost 5000 notifications in the first month of 2005 alone. The age group affected was too old to have received the routine MMR immunisations around the time the paper by Wakefield et al. was published, and too young to have contracted natural mumps as a child, and thus to achieve a herd immunity effect. With the decline in mumps that followed the introduction of the MMR vaccine, these individuals had not been exposed to the disease, but still had no immunity, either natural or vaccine induced. Therefore, as immunisation rates declined following the controversy and the disease re-emerged, they were susceptible to infection. Measles and mumps cases continued in 2006, at incidence rates 13 and 37 times greater than respective 1998 levels. Two children were severely and permanently injured by measles encephalitis despite undergoing kidney transplantation in London.

Disease outbreaks also caused casualties in nearby countries. Three deaths and 1,500 cases were reported in the Irish outbreak of 2000, which occurred as a direct result of decreased vaccination rates following the MMR scare.

In 2008, for the first time in 14 years, measles was declared endemic in the UK, meaning that the disease was sustained within the population; this was caused by the preceding decade's low MMR vaccination rates, which created a population of susceptible children who could spread the disease. MMR vaccination rates for English children were unchanged in 2007–08 from the year before, at too low a level to prevent serious measles outbreaks. In May 2008, a British 17-year-old with an underlying immunodeficiency died of measles. In 2008 Europe also faced a measles epidemic, including large outbreaks in Austria, Italy, and Switzerland.

Following the January 2011 BMJ statements of fraud by Wakefield, Paul Offit, a pediatrician at Children's Hospital of Philadelphia and a "long-time critic of the dangers of the anti-vaccine movement", said, "that paper killed children", and Michael Smith of the University of Louisville, an "infectious diseases expert who has studied the autism controversy's effect on immunization rates", who said "clearly, the results of this (Wakefield) study have had repercussions."