A: Public health authorities near you
During a recent Twitter exchange, Andre Picard, the Globe and Mail’s health columnist, asked me “who exactly is recommending a third MMR dose” after I referred to increasing interest in extra shots. One answer: Public Health Agency of Canada. On its website, it now states: “Prevention of infection by immunization is not just for children; adults require immunization to address waning immunity against some vaccine preventable diseases.” The measles vaccine is such a disease.
PHAC then goes on to explain that “All adults in Canada without contraindications should be routinely immunized against vaccine preventable diseases.” In its “Recommendations for routine immunization,” PHAC recommends one additional MMR dose for susceptible adults born after 1970. Many of those adults would have had two previous MMR shots and many of them would be susceptible, either because the vaccine waned or because it never took.
PHAC then ups its recommendation for susceptible adults to two additional doses for those considered to be at specific risk — these include anyone travelling outside North America, any student in a post-secondary educational setting and any military or health care personnel.
CDC’s recommendations somewhat align with PHAC’s. On both sides of the border, the health care community is coming to terms with what may well turn out to be a life-long need to be re-vaccinated.
Last April an article in the Ottawa Citizen, “Adults vaccinated against measles decades ago aren’t all immune, experts say,” confronted the issue of waning immunity and made the case for upping the number of doses. “There is a concern we may need to vaccinate more — double dosing for adults as we do for children,” said virologist Earl Brown, a professor emeritus at the University of Ottawa.”
And this January, interest in additional measles vaccination became evident following the outbreak at Disneyland. “Have you had you’re your measles shot? “Maybe you need another,” a January article on the NBC News website, reported that “many adults who were vaccinated for measles decades ago as children are now highly susceptible to the virus—perhaps as many as one in 10 of those who were immunized, infectious disease experts say.” The upshot is that “previously immunized adults should consider getting measles booster shots, said Dr. James Cherry, who specializes in pediatric infectious diseases at Mattel Children’s Hospital UCLA in Los Angeles.
“’It may well be important in the future we should give additional doses to adults … we have people … who are now 40 years out from vaccination and so some of these people will get measles because their protection has dropped.”
The good news: Experts believe that additional MMR shots for adults would be very safe.