America is seeing the largest outbreak of measles in decades, and even vaccinated children are among the infected. Although doctors are blaming the outbreak on foreign travel and unvaccinated children, the MMR (measles-mumps-rubella) vaccine has no protective effect on at least 5 per cent of children who are vaccinated.
The outbreak is wrong-footing many young doctors, some of whom have never seen a case of measles and so aren't diagnosing it correctly.
Nadia Qureshi at Loyola University Health System says the vaccine protects 95 per cent of children, and this can rise to 98 per cent after a second dose. Even so, two per cent of a population is at risk for developing measles even in an area that has achieved 'herd immunity' where more than 95 per cent of children have been vaccinated.
She blames the latest outbreak on falling rates of vaccination-even though it is compulsory in most states-and to travel to countries where measles is rife.
(Source: Loyola University Health System press release)