The governor of Washington declared a public health emergency last week after an outbreak of measles. As of Monday, there were 36 confirmed cases in the state.
The outbreak has yet again put the anti-vaccine movement under the spotlight – and especially parents who refuse to immunize their children from infectious diseases. Washington’s state legislature has introduced a bill that would ban personal exemptions from the measles vaccine.
In 2014, there were 667 cases of measles recorded in the US – the highest number since 2000. And vaccination rates were high that year too; only 0.2% of kindergarten children in 2014 received medical exemptions from vaccines, according to the Centers for Disease Control and Prevention (CDC). But because of the highly infectious nature of the virus, measles can spread quickly if just a small percentage of the public are not vaccinated.
The role of vaccinations in preventing contagion was researched in a letter published in the Journal of the American Medical Association in 2017.
The author, Nakia S Clemmons, looked at measles cases from 2001 to 2015 and how many of the patients had been vaccinated. Clemmons, who works in the viral diseases division of the CDC, concluded that failure to vaccinate is linked to the spread of measles.
Of the 1,789 measles cases among US residents that were reported to the CDC during that four-year period, nearly 70%, or 1,243 individuals, were unvaccinated. The most vulnerable group was babies and toddlers; just two of the 163 infants aged six to 11 months who became sick had been vaccinated. And only 11 of the 106 toddlers aged 12 to 15 months with measles had been vaccinated.
Measles is a highly contagious disease that was eliminated from the US in 2000. But the virus has since been reintroduced by travelers. A tourist visiting Disneyland is thought to have caused a significant multi-state outbreak of measles in 2015.
