Question

Consider the following statements with regard to mass vaccination programmes in a disaster-affected zone:
The WHO recommends that the typhoid and cholera vaccines should routinely be given in endemic areas.
The mass vaccination of the population against tetanus is usually unnecessary.
If tetanus immunization was received more than 5 years ago in a patient who has sustained an open wound, a tetanus toxoid booster is an effective preventive measure.
As a large-scale measure, typhoid and cholera vaccines have proven to be effective public health strategy.

Answer 1

sorry I'm not sure
I can't understand your given step