We've been saying it for nearly a decade now: Vaccinating infants and schoolchildren against the flu will result in major health benefits. Now the results of a new study led by Dr. John Brownstein of Children's Hospital Boston and published in the Canadian Medical Association Journal provide further evidence that herd immunity (protecting non-immunized populations by increasing overall rates of vaccination) is very effective.
Beginning in the 2006-2007 flu season, the U.S. Advisory Committee on Immunization Practices expanded the recommendation for seasonal flu shots to children between 2 and 4 years old. In order to determine whether the new guidelines would impact hospitalization rates, researchers compared data on over one million emergency room visits from the 2000-2001 through the 2008-2009 flu seasons at Children s Hospital Boston and the Montreal Children s Hospital, which did not issue a similar vaccine expansion recommendation until 2010. Visits to the emergency room dropped by 34 percent among children at Boston Hospital compared to the hospital in Montreal, while declines in hospitalization rates among other pediatric age groups fell by 11 to 18 percent as well.
The Centers for Disease Control and Prevention is now recommending that all individuals six months and older receive an annual flu shot.
ACSH s Dr. Gilbert Ross observes that, Older people suffer from the life-threatening consequences of flu much more commonly than children do. Therefore, he says, lives will be saved as older relatives don t get infected from the infants and children they live with. The small cost of expanded vaccination pays off many times over in ER and hospital savings.
Results of another study presented yesterday at an infectious diseases medical conference in Chicago highlight the importance of paying vigilant attention to children s vaccine schedules. Led by Dr. David Witt, chief of infectious disease at the Kaiser Permanente Medical Center in San Rafael, researchers found that the immunity conferred by the whooping cough (pertussis) vaccine may wane after only about three years. The risk of contracting the disease was as much as 20 times higher in children three years or more after they received the last shot in a recommended series of whooping cough vaccines. After reviewing last year s data on about 15,000 kids in Marin County, where the California pertussis epidemic broke out, the results of the study demonstrate that the whooping cough vaccine lacks long term effectiveness, and thus children may require a booster shot at around the age of 11 or 12 to maintain immunity. In the late 1990s, the U.S. began using a newer and safer type of childhood whooping cough vaccine compared to previous years, and though its short-term effectiveness is 90 percent or higher, it may not provide enough long-term protection. That s why, says Dr. Ross, enforcing the recommended fifth booster shot for children is the most effective way to prevent recurrence of what proved to be a major whooping cough epidemic.