The re-emergence of measles in developed countries: time to develop the next-generation measles vaccines?

Measles is the most transmissible infectious disease known n humans, and remains one of the top causes of death in chilren worldwide. Even in highly developed countries, measles ills approximately three of every 1000 persons infected. While o treatment exists for measles, prevention in the form of accination has been available since the 1960s. Despite the sigificant global morbidity and mortality of measles, considerable rogress is evident. Just a decade ago, in 2000, measles killed n estimated 777,000 people a year worldwide. In 2010, measles illed only 160,000 worldwide—a testament to widespread use of accine. But concerns lurk, unnoticed for the most part. Despite the forementioned gains measles is re-emerging as a serious public ealth threat, and outbreaks are occurring even in highly developed ountries where vaccine access, public health infrastructure, and ealth literacy are not significant issues. This is unexpected and a orrisome harbinger—measles outbreaks are occurring where they re least expected. As illustrated in Table 1, since 2005 these outreaks have also occurred in the U.S. – with surprising numbers f cases occurring in persons who previously received one or even wo documented doses of measles-containing vaccine. In fact, as of eptember 2011, the U.S. has had 15 measles outbreaks with 211 onfirmed cases—the highest number of cases since 1996 [1,2]. Large measles outbreaks are also occurring in many other eveloped countries [3–6]. Thirty-three European countries have eported outbreaks of measles this year [5] with more than 30,000 nown cases [4]. The UK has declared measles once again endemic 3]. In the first seven months of 2011, France alone suffered 14,025 ases of measles, and Spain has reported 1777 cases [7]. In none of hese countries are vaccine access, nor health care infrastructure, erious issues. Where data exist, such outbreaks result from both ailure to vaccinate, and vaccine failure. Failure to vaccinate is a serious socio-cultural issue, and signifcantly hampers public health goals. Measles immunization rates, articularly in certain areas of the U.S. and western Europe, have lateaued or decreased and experts suspect this is a result of the ow-debunked notion that measles vaccine caused autism—a false laim that adversely influenced MMR vaccination choices among generation of parents. In addition, few current parents have ny direct experience with measles and are uninformed about its nfectivity, morbidity, and mortality. Because measles outbreaks ave occurred in scattered areas of the country, the average parnt is unaware of the danger, and feels no urgency to respond y immunizing their children—thus further enlarging the pool of usceptibles.