A single dose of the killed oral cholera vaccine (Shanchol) proved to be effective in children 5 years and older and in adults, according to a randomized trial conducted in Bangladesh, where young children are most affected by cholera. The vaccine is normally given in 2 doses, but the single dose was studied because it would be more pragmatic to administer (Quadri F et al. N Engl J Med. 2016;374:1723-1732).
A total of 204 700 people were randomly assigned to receive a single dose of oral cholera vaccine or oral placebo. A single dose of the vaccine provided 40% protection against all cholera and 63% protection against severely dehydrating cholera episodes for at least 6 months after vaccination. The single-dose regimen, however, provided an inadequate 16% protection in children aged 1 to 4 years, possibly because they have less natural immunity against cholera. For children who were vaccinated between 5 and 14 years of age and when 15 years or older, the single-dose vaccine was 63% and 56% effective, respectively. The single dose of the vaccine provides at least short-term protection to older children and adults and therefore could be used to help contain cholera epidemics.
Slomski A. Single Dose of Cholera Vaccine Provides Short-term Protection. JAMA. 2016;315(24):2656. doi:10.1001/jama.2016.7253