A group of several health workers travels in a vehicle permanently assigned to them to areas not served by existing health services, in order to vaccinate and provide other health services. The advantage is that this may be the only way to immunize children and pregnant women in rural areas or in urban communities without health services. The disadvantages are that transportation and per diem expenses are often prohibitively high, and supervision is very difficult.
“Hard-to-Reach Groups”
Certain sectors of the population may be difficult to reach because of geographic barriers or sociocultural reasons. Those who are difficult to reach because of geographic barriers can be served through a combination of home visits, outreach activities and mobile teams. To some extent, the cost of immunizing hard-to-reach groups may become prohibitive.
Those whose religious beliefs prohibit or hinder immunization are examples of groups that are difficult to reach for sociocultural reasons. Overcoming these barriers requires a great deal of patience, understanding, imagination and conversations with local religious leaders and other influential people before the community accepts immunization.
Large-Scale Campaigns
Usually, health personnel periodically suspend their other regular activities in order to devote themselves exclusively to vaccination for a short period, such as a week or a month. The advantages of this procedure are that, with good promotion, it can awaken interest and obtain the cooperation of the community and health personnel.
The mobilization of community volunteers may result in broader vaccination coverage than would have been possible with limited staff. On the other hand, it has the disadvantage that it is generally not possible to keep personnel and the community interested. Coverage is usually good during the first campaign, but declines the following year.
For this reason, many countries have begun to concentrate their activities on systematic and continuous vaccination rather than on campaigns. The suspension of other activities during campaign days causes disruptions in other health programs.
Immunization campaigns are useful means of introducing vaccination in areas with no previous experience, with insufficient staff to cover the target population, or with both circumstances. They should be replaced by systematic and permanent activities as soon as feasible.
After deciding on one of the tactics listed above, another decision must be made regarding how to implement it: a) through house-to-house vaccination, or b) through vaccination at a meeting point. The advantages and disadvantages of each are as follows:
a) In house-to-house immunization, health personnel visit individual homes to locate and vaccinate children and pregnant women. This tactic may be used as part of outreach activities, mobile teams and large-scale campaigns.
Its advantages include the possibility of identifying children at greatest risk of contracting diseases and immunizing them. Personnel get to know the people in the area, and the people get to know the personnel. At the same time, health education and other health services can be provided.
The disadvantages are that vaccination at home may be less cost-effective when the time required to visit each house and vaccinate eligible members is taken into account. This method requires health personnel to travel and may involve per diem costs. These activities are very difficult to supervise. Vaccine may be wasted because of the small number of children immunized.
b) In immunization at a meeting point, health personnel inform the public to go to a centrally located place at a given time, where staff and equipment gather for a vaccination session. This procedure is exemplified by immunization at the health center, but it may also be used as part of outreach activities, mobile teams and large-scale campaigns.
Its advantages include efficient use of personnel. All equipment can be transported in a vehicle, if it is not already on site, and set up for more organized vaccination sessions.
Its disadvantages are that the result depends on the motivation of the people who bring the children to the location. The costs in terms of the time and money needed to reach the meeting point may be prohibitive. People who may not have heard about immunization, or who do not decide to bring their child, may not be served.
