analysisBy Winifred Ogbebo
Last month, a three- year old child was inflicted with the wild polio virus in Dabra ward of Katsina State. What is news, however, is the fact that the child was said to have been vaccinated eight times by the father, who also disclosed that the vaccinators only missed giving the child two drops of the oral polio vaccine during the last round of the exercise.
This development has met with shock and disbelief as quite a number of people have always held to the common thread that two drops of the vaccine was enough to ward off the debilitating disease.
Describing it as a sad reflection of the system, the NMA president, Dr Osahon Enabulele, said if a vaccine is not well stored in terms of the cold chain arrangement, one could have denaturalization of even the constituent of those vaccines and that invariably can affect the potency of the vaccines.
"The cold chain is such that you must have constant power supply to power the cold chain arrangement and we know that we have epileptic power supply in our country moreso in the rural communities," said he.
Though debates persist regarding the safety of vaccines, most pediatricians still recommend that babies be vaccinated because it strengthens their immune systems by teaching them to recognize potentially dangerous germs and fight them off.
According to experts, a child's immune system plays an important role in keeping him/her healthy. The immune system is a group of organs, tissues and cells that fight off germs, bacteria and other microscopic organisms that have the power to make the child sick, explains KidsHealth.org, an online health and parenting information resource maintained by the Nemours Foundation.
When a child has a healthy immune system, s/he's less likely to get sick and more likely to recover quickly when s/he does catch something.
Though the common thread is that children who are not vaccinated are at greater risk of contracting these diseases, so do those children who have not taken full dosage of the vaccine.
In what he calls the wonders of the immune system, Dr Kabir of the National Primary Health Care Development Agency explains how it works. "When an agent (vaccine or natural exposure) is introduced into the body, antigens are activated. When they activate, antibodies are then created to lock in on the virus to destroy it. Some vaccines do not offer 100% protection."
A vaccine will either be in the form of a weakened pathogen (virus or bacteria) or one which has been killed. This is injected into the body, and the immune system will react and eradicate it from the body. It will then be able to 'remember' this virus and if the virus is caught again, the immune system will kill it before it has time to harm the body at all. This is why once you have had a full vaccine course you cannot ever be affected by that disease again. This is what we call immunity."
According to him, the more people who are immunised against a disease, the smaller the pool of people available for transmission. "This makes everyone safer in what is known as herd immunity by reducing likelihood of transmission and opportunity for the virus to mutate. Some viruses have been wiped out by this method."
Herd immunity theory proposes that, in contagious diseases that are transmitted from individual to individual, chains of infection are likely to be disrupted when large numbers of a population are immune or less susceptible to the disease. The greater the proportion of individuals who are resistant, the smaller the probability that a susceptible individual will come into contact with an infectious individual.
The proportion of immune individuals in a population above which a disease may no longer persist is the herd immunity threshold. Its value varies with the virulence of the disease, the efficacy of the vaccine, and the contact parameter for the population.
"No vaccine offers complete protection, but the spread of disease from person to person is much higher in those who remain unvaccinated,"says Dr Kabir.
But complications arise when widespread vaccination is not possible or when vaccines are rejected by a part of the population.
According to the July UNICEF Social Data Analysis, the proportion of missed children remains high in some high-risk states.
"Sokoto has the highest proportion (8.6%), followed by Kano (7.8%), Jigawa (7.7%) and Katsina (7.6%). Data from the States of Yobe and Kaduna are not yet available due to the postponement of the campaign. 'Child absent' remains the main reason for missed children, accounting for over 72% of the total number of missed children. Non-compliance as a reason for missed children was 22% during the July campaigns. The states of Sokoto (35%) and Kano (34%) have the highest proportion of non-compliance"
Nigeria's effort to eradicate the wild polio virus is to a large extent hinged on the vaccinators but, unfortunately, they still constitute a major setback to the country's actualization of a polio-free endemic nation.
The potent question is how ready and prepared are they?
Since many years ago the Immunisation Plus Days began till date, vaccinators are still groping in the dark on vital details regarding the exercise.
During last month's IPDs review meeting of the Katsina Local Governemnt Area of Katsina State, there were recounted incidences of vaccinators flopping on the job.
An independent monitor gave an instance of how seven houses in a row were marked N throughout. However, acting out of curiosity and probably on instinct, he had gone into one of the homes to verify only to discover that there were indeed, two eligible children for vaccination in one of the homes.
A UNICEF staff also alleged cover ups by vaccination teams stressing on the case in Barnuwa village. She said there was no report of cases of non compliances by the villagers as the vaccinators did not record it.
She noted that it was concealment by the care givers as they are also from the same village
In Edo and Katsina States, for example where this writer has gone for monitoring, a case was recounted of how the health workers marked a house first for immunization before meeting the lady of the house who was sitting on the veranda of the house carrying her child who was yet to be immunized.
Besides, they also contend with problems of calculation and filling of the micro plan.
Last month, between 7-10 July, 2012, Nigeria conducted large-scale door-to-door polio immunization campaigns in the States of Bauchi, Borno, Jigawa, Kano, Katsina, Kebbi, Niger, Sokoto and Zamfara, targeting children under five years. Kaduna and Yobe States were forced to postpone their campaigns due to a deteriorating security situation.
Nigeria had witnessed a 95 per cent decline in the number of polio cases in 2010 and was very close to stopping the transmission of the wild polio virus. However, as at July 20, 2012, Nigeria has recorded 57 new cases of wild polio virus in 10 states compared to 25 cases during the same period in 2011.