Expert opinions differ on the applicability, feasibility, and impact of cholera reactive vaccination in epidemic situations (14 – 19 ); thus far, experience in these situations is limited to small outbreaks in stable populations (20, 21 ).
Despite several reactive vaccination campaigns, the epidemic spread throughout Malawi.
With proper disease detection programs in place, this evidence along with epidemiological data could further support the potential use of this vaccine as part of a reactive strategy in an epidemic situation.
10 In 2010, WHO revised guidelines on the use of OCV and included a recommendation that in epidemic settings, reactive vaccination be considered as an additional control measure in conjunction with other prevention and control strategies.
Polysaccharide vaccines, used mainly for reactive mass vaccination during epidemics, are poorly immunogenic in children under 2 years of age (except for serogroup A), induce short-lived protection (3 5 years) in children, and have a limited ability to reduce nasopharyngeal carriage and induce herd immunity [7].
The only available control strategy for serogroup W epidemics is reactive campaigns with trivalent or quadrivalent meningococcal polysaccharide vaccine.
Until 2010 the fight against meningitis was based primarily on halting ongoing epidemics through reactive vaccination with bivalent (AC), trivalent (ACY) and tetravalent (ACYW) polysaccharide vaccines [ 17].
Many of the reactive vaccination campaigns conducted during this epidemic were carried out relatively late in the course of the epidemic in the given areas.
In reality, reactive vaccination only occurs when an epidemic threshold is reached, so only cases that occur in areas that reach an epidemic threshold will yield a reactive vaccination cost.
By contrast, reactive campaigns selectively target districts experiencing epidemics and not the national population.
