In Cholera Outbreaks, A Single Vaccine Dose Can Work As Well As The Standard Two

A child is vaccinated against cholera in Juba, South Sudan. Credit: UN Photo/JC McIlwaine Oral cholera vaccines are typically administered in two doses, but experience and recent research reveal this may not always be the best approach. Faced with an outbreak in South Sudan, epidemiologist Andrew Azman and his colleagues encountered a difficult decision: vaccinate as many people as possible with a single dose, or fewer with the standard two. Based on emerging research, they chose the first option and found that for the kind of short-term protection needed to stop an outbreak, a single dose works as well. ResearchGate: How long has this vaccine been in use? Andrew Azman: Injectable cholera vaccines were abandoned decades ago, because they didn't work very well and caused adverse reactions. In the 1980s, the research community started developing oral vaccines, which work better. Cholera is an enteric disease, so stimulating a response in the gut is going to be the most effective way of tackling it. Researchers in Sweden, the US, and Bangladesh developed the first version of the oral vaccine. It works very well, but is quite expensive and requires a buffer solution, which means you need clean water with every dose you give. For both these reasons, it's not well suited for large-scale humanitarian vaccination campaigns, though it's been used in travelers for decades. In the 1990s, a similar vaccine without the component requiring the buffer solution was developed in Vietnam...
Source: Science - The Huffington Post - Category: Science Source Type: news