Vaccines

Measles Cases Could Triple Even With Just A Small Decline In Vaccinations

Small Drop in Vaccination Could Triple Number of Measles Cases in United States

Despite the societal benefits of vaccines and the known consequences of not using them, it is astounding that delays in acceptance or the refusal of taking vaccines exists in various parts of the world. Vaccine hesitancy is a major public health concern that needs to be highlighted.

Given increasing parental decisions not to vaccinate their children, investigators from the U.S. wanted to understand what the effect of small reductions in vaccine coverage on measles cases were. Nathan Lo, from the Stanford University School of Medicine in California, estimated the disease burden and economic costs associated with declines in the measles-mumps-rubella (MMR) vaccination rate.

“Routine childhood vaccination is declining in some regions of the United States due to vaccine hesitancy, which risks the resurgence of many infectious diseases with public health and economic consequences,” the authors wrote in the journal JAMA Pediatrics.

US State Vaccine Exempotions

The study set out to find the number of measles cases in U.S. children. From there, researchers used vaccine data from the Centers for Disease Control and Prevention to simulate county-wide MMR vaccine coverage for children ages 2 to 11. They then used a mathematical model to estimate the impact of decreasing vaccination rates, taking into consideration the infectiousness of the disease while simulating situations in which measles is introduced by a traveller into the U.S. They calculated the number of cases that would be expected if the MMR vaccination coverage was to decline. The researchers repeated this process thousands of times, changing the variables and scenarios each time for each state. The model was checked for its accuracy using data on measles cases from England and Wales.

At baseline, MMR vaccine coverage was at 93 percent, and the prevalence of non-medical exemptions was at 2 percent. This would yield 48 measles cases annually in this age group across the U.S. However, if vaccine coverage dropped by 5 percent, the estimated number of measles cases would increase to 150, a threefold increase. This could cost the public sector $2.1 million. That’s $20,000 per case of measles. Still, the researchers warned that results of the study may be underestimated! The study did not take into account other variables, such as cost of illness, parental time off work, hospitalization, or other societal factors.

Peter Hotez, Dean of the National School of Tropical Medicine…