Compulsory vaccination at school entry in addition to current immunization programs will be necessary in several high-income countries to prevent future measles resurgence, according to a study published online May 17 in BMC Medicine.
Filippo Trentini, Ph.D., from the Bruno Kessler Foundation in Trento, Italy, and colleagues modeled the evolution of measles immunity profiles in seven distinct countries for 2018 to 2050 and evaluated the effect of possible adjustments to immunization strategies. These strategies include the enhancement of coverage for routine programs already in place and the introduction of a compulsory vaccination at primary school entry in countries where universal school enrollment is likely achieved.
The researchers found that under current vaccination policies, the susceptible fraction of the population would remain below the measles elimination threshold only in Singapore and South Korea. Either an increase of coverage of routine programs >95 percent or the introduction of a compulsory vaccination at school entry with coverage >40 percent are needed to maintain a proportion of susceptible individuals of <7.5 percent (threshold required for elimination) through 2050 in the United Kingdom, Ireland, the United States, and Australia. In Italy, while the implementation of mandatory vaccination at school entry would be beneficial, strategies targeting adults would also be required to avoid future outbreaks.
"Current vaccination policies are not sufficient to achieve and maintain measles elimination in most countries," the authors write.
