The authors posit that their review clears up a few discrepancies gleaned from past studies on the efficacy and effectiveness of the cholera vaccines. “For example, efficacy for cholera vaccines tends to be lower than effectiveness, a scenario that’s opposite from that of most other vaccines and one that has puzzled researchers,” according to the press release. Dr. Azman theorizes that this may be because studies examining efficacy are oftentimes carried out in regions where cholera is a common disease that children are faced with and exposed to, “a population in which these vaccines aren’t as effective.” Therefore, Dr. Azman says that this could explain why efficacy is lower than effectiveness.
The results of the review also show that the available vaccines are not providing optimal protection for a key population at risk for the disease, findings that Dr. Azman feels “should have enormous implications for vaccine policy.” Due to these findings, researchers need to identify the best way to use the vaccines available in order to provide stronger coverage of young childrenm especially until a new vaccine regimen is developed. Meanwhile, adults who live in households with young children should ensure that they receive their recommended vaccinations.
Furthermore, the finding that a 1-dose regimen may be able to provide the same amount of protection as a 2-dose regimen can be monumental for regions continually hit by disease outbreaks. Cholera vaccines cost, on average, $1.85 per dose; but if the dosage is cut in half, then so are the associated costs. Dr. Azman suggests that by being able to give 1 dose instead of 2 in outbreak situations, health officials can potentially stretch out the supply to cover “twice the number of people.”
“In cholera-prone areas, public health decision makers don’t always have the luxury of caring about the outbreak risk in 2 years,” Dr. Azman explained. “They care about the risk of transmission tomorrow or in 2 weeks or next month. Being able to vaccinate twice the number of people with a limited quantity of vaccine can be very important.”
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