Cluster Immunization - Children & Adults

Reducing vaccine preventable disease and mortality among children under-five years of age is crucial in any health-decision made by the villagers. This realization made Prof. Jajoo and his team to consider unique strategies of cluster (pulse) immunization over a clinic-based, individualized approach starting in the year 1982.  The absence of any vaccine preventable diseases in the adopted villages since this approach was first taken is in sharp contrast to the national statistics on childhood mortality. The pioneering nature of this initiative is evident from the fact that the state government finally adopted ‘cluster immunization’ in the year 1996, a good decade and a half after this initiative was first taken.

Scope of the problem

By the year 1981, an affordable, acceptable, accessible Rural Health Assurance Scheme, centered round Kasturba Hospital, Sevagram was in place.

Professor Jajoo remembers a particular incident which brought home the idea that something had to be done to decrease childhood mortality in the villages. He said ‘We actively participated to mobilize support for the government backed policies of family planning as a top priority. To promote a small family norm, we went to the villages, put up posters, arranged movie shows promoting family planning, identified target groups and made personal visit to them, arranged for vehicles for their transportation to the hospital, and even assured them a share in the promoter’s incentive.’

He added, “Despite all these efforts, we were not having any measurable success. We found the answers for this lack of success to the very high under five of age mortality largely due to preventable illnesses. None of the villagers with even two children were willing to risk undergoing permanent methods of family planning unless there were guarantee’s about their children surviving to adulthood in the face of the high under five years of age mortality among the children.’

 Zama Ambulkar, a farmer from Nagapur village, has something more to teach us –‘Doctor, we want more kids, they are an asset to an agriculturist like me. Labour is too costly these days, I need dependable manpower to help me in the field.’

‘This entire exercise taught us that unless the under five years of age mortality is reduced, the security for the old age is provided and agriculture becomes profitable, any amount of propaganda and wishful thinking or incentives will not convince the poor village folk about the benefits of small family size.”- said Professor Jajoo.
Professor Jajoo reflects on this problem, “The current under-five mortality of 63 per 1000 children in 2010 is a fraction of the 147 deaths per 1000 live-births back in 1980 at the time we chose to tackle this problem.”

Towards An Appropriate Mass Immunisation Strategy

“A clinic-based, individualized approach was not ideal for mass immunization coverage especially for poor, uninformed and distant villagers, given the low priority they give to preventive health, the inaccessibility of vaccination facility at the door-step and difficulty in maintenance of cold chain for vaccine delivery. The alternate doorstep house-to-house based immunization strategy was too labour intensive (requiring as many as 5 visits per child up to 1 year of age) so as to render it impractical. The spotty overall immunization coverage was not at all adequate and put the whole community at risk for future epidemics. We required at least 90% immunization coverage of those susceptible to diseases to achieve herd immunity (or community immunity).”- said Professor Jajoo.

Achieving adequate herd immunity -a form of immunity that occurs when the vaccination of a significant portion of a population (or herd) provides a measure of protection for individuals who have not developed immunity became the initial goal so as to mitigate under-five mortality among the villagers.

On the ground…

In 1982, cluster (pulse) immunization strategy (proposed for first time by Dr. Jacob John from Vellore) with the goal of increasing her immunity and halting the spread of disease epidemics among the villages was instituted.

The strategy involved initial publicity for the program with a slide-shows and movie presentations on health education for the villagers. Immunization at no cost was provided on starting early morning (7 am) on a predetermined day so as to get maximal participation before the villagers left for working in the fields. The entire susceptible population in the village was vaccinated (measles, BCG, DPT and poliomyelitis for under-five age group and tetanus toxoid for adults). Thereafter, follow-up monthly visits from January to May were made by the mobile health team.

Starting in 1983, once full immunization coverage had been achieved, the strategy was modified and cluster coverage was limited to newborns,new daughter-in-law's and pregnant women (for tetanus toxoid). With this, the pregnant mother required only one booster, which she could receive any time in pregnancy by clinic-based immunization strategy. This saved on valuable resources required as only four village visits were now required from January to April to achieve 95% coverage for the susceptible diseases. This also helped empower the village-based worker to shoulder the responsibility for the village community.

Impact of the programme…

The eligible child population in the 12 villages, was

  • 315 for Measles vaccine
  • 266 for DPT vaccine
  • 819 for Oral polio vaccine

“Success came in the form of zero cases of vaccine preventable illness including measles after 1983 in any of the adopted villages. This proved, beyond doubt, the distinct edge of cluster immunization over hospital and door-to-door immunization, an unnecessary drag on the already over-strained healthcare budget.”- said Professor Jajoo.  

The pioneering nature of this initiative is evident from the fact that the Government of state of Maharashtra adopted ‘cluster immunization’ in the year 1996, a good decade and a half after the same was taken up by Kasturba Health Society.

The absence of any vaccine preventable diseases in the adopted villages is in sharp contrast to the national statistics on childhood mortality. Today, the United Nations estimates that 2.1 million Indian children die before reaching the age of 5 every year – four every minute. Vaccine preventable diseases continue to extract a heavy toll and contribute significantly among these to the under-five mortality in India. Full immunization coverage is noted in only a fraction of all children in India (44% of all children, in a recent national survey). View More Images