Measles study raises questions about timing of vaccination

A second study from Quebec is calling into question the timing at which young children are vaccinated against measles. The new research shows that teenagers who received the recommended two doses of measles vaccine but who got the first shot when they were 12 months old were six times more likely to go on to contract the disease than those who got their first dose at 15 months. The work was done to try to puzzle out why a number of teenagers who would have been assumed to have been protected — because they got two doses of vaccine in childhood — nevertheless were infected during Quebec’s large measles outbreak in 2011. More than 700 measles cases were reported in that outbreak. Lead author Dr. Gaston De Serres of Quebec’s provincial public health agency presented the work at a major international infectious diseases conference in San Francisco. The study was a follow-up to an...