Oral polio vaccine (OPV)

The oral polio vaccine (OPV) was developed in 1961 by Albert Sabin. Also called “trivalent oral polio vaccine” or “Sabin vaccine”, OPV consists of a mixture of live, attenuated (weakened) poliovirus strains of all three poliovirus types.

OPV produces antibodies in the blood to all three types of poliovirus. In the event of infection, these antibodies protect against paralysis by preventing the spread of wild poliovirus to the nervous system. 

OPV also produces a local, mucosal immune response in the mucous membrane of the intestines. In the event of infection, these mucosal antibodies limit the replication of the wild poliovirus inside the intestine. This intestinal immune response to OPV is thought to be the main reason why mass campaigns with OPV can rapidly stop person-to-person transmission of wild poliovirus.

Advantages

• OPV is administered orally. It can be given by volunteers and does not require trained health workers or sterile injection equipment.
• The vaccine is relatively inexpensive. In 2011, the cost of a single dose for public health programmes in developing countries was between 11 and 14 US cents. 
• OPV is safe, effective, and induces long-lasting immunity to all three types of poliovirus.
• For several weeks after vaccination, the vaccine virus replicates in the intestine, is excreted in the faeces, and can be spread to others in close contact. This means that in areas where hygiene and sanitation are poor, immunization with OPV can result in the “passive” immunization of people who have not been directly vaccinated.

Disadvantages

Although OPV is safe and effective, in extremely rare cases (approx. 1 in every 2.7 million first doses of the vaccine) the live attenuated vaccine virus in OPV can cause paralysis. In some cases it is believed that this vaccine-associated paralytic polio (VAPP) may be triggered by immune deficiency. 

The extremely low risk of VAPP is well known and accepted by most public health programmes in the world because without OPV, hundreds of thousands of children would be crippled every year. 

A second disadvantage is that very rarely the virus in the vaccine may genetically change and start to circulate among a population. These viruses are known as circulating vaccine-derived polioviruses (cVDPV).

Safety

OPV is an extremely safe vaccine. All OPV used in supplementary immunization activities for the Global Polio Eradication Initiative is pre-qualified by WHO and procured through UNICEF. In 2006, WHO issued a statement to affirm the quality and safety of OPV.

Efficacy

OPV is highly effective against all three types of wild poliovirus. When this vaccine is used however, there is competition among the three viruses to cause immunity, which results in protection but not with equal efficiency for each type: it is most effective against type 2.

One dose of OPV produces immunity to all three poliovirus serotypes in approximately 50% of recipients. Three doses produce immunity in more than 95% of recipients. Immunity is long-lasting and probably life-long.

Recommended use

In most countries, OPV remains the vaccine of choice in routine immunization schedules and supplementary immunization activities. 

Where more than one type of wild poliovirus is circulating, OPV is epidemiologically and operationally the best vaccine to use because protection develops to each of the three types of polio virus.

Related links

WHO position statement: safety and pre-qualification of oral polio vaccine (OPV)

For further information visithttp://www.polioeradication.org/Polioandprevention/Thevaccines/Oralpoliovaccine(OPV).aspx

HIGH INFANT MORTALITY RATE IN NIGERIA

UNICEF’s Chief of Field Office in charge of Katsina and Kano States, Padmavathi Yedla, has explained that the solutions to high infant mortality rate in Nigeria are not expensive but they are not properly observed because social norms are opposed to them.

Yedla, who stated this at the weekend while speaking at her maiden meeting with Katsina newsmen, was disturbed by the high rate of infant mortality, particularly in the North.

She expressed that even in the North with the highest rate of infant mortality; many women do not practice exclusive breast feeding.

“The reason they give is that their mothers – in – law or their mothers say when a child is not given water, the child will not be healthy. What happens is that the water they often give to the children is not pure; it is already contaminated.”

Yedla said another major reason for high infant mortality is malnutrition, saying “if you look at the cycle of malnutrition, many children (girls) are married at the age when they are not completely ready for marriage and these girls themselves are very malnourished; they are not very healthy by the time they get married.”

According to her, a child born to a malnourished mother doesn’t have adequate resistance against ailment caused by bacteria contamination.

“So, the solutions are there but the social norms prevent us because we believe that a child needs more than breast milk. That’s not true. The child’s stomach is very small and when the child is given water, the child’s stomach is filled up but water does not contain any nutrient.”

She also said it is unfortunate that lack of access to safe water and sanitation procedures remain the major source of diarrhea; a one of the killer diseases of children who are under five years.

She was confident that the proactive role of media on immunisation and malnutrition among others would no doubt improve the health condition of the populace at the grassroots.

By: Andy Asemota
Leadership News

Polio Eradication End Game and Certification Programme

These activities were part of the training workshop on polio eradication organized by FCT health administration in collaboration with WHO for Guild of Medical Director (GMD) and private health sector practitioners.
This was held in response to the recent outbreak of polio in North East Nigeria. The training dwelt on how to tackle polio and contain its further spread. Issues on urgent large-scale immunization of the affected areas and effective surveillance measures to detect any threat of further spread were discussed.

Case was also made for sustained efforts at checking reemergence of other communicable diseases that have largely been controlled/eradicated, such as measles, neonatal tetanus, yellow fever, cholera, meningitis, guinea worm disease and Ebola virus disease.

IMMUNIZATION SCHEDULE UPDATE

In view of the emerging new infectious diseases and reemergence of those diseases that are deemed to have been eradicate or controlled, there is need to update the immunization schedule to cover for additional challenges posed by these upsurge. The immunization schedule as presents constituted falls short of required standard of care.

A case is being made for the inclusion of Human Papilloma Virus (HPV) vaccine in the routine immunization schedule for the vulnerable age groups for prevention of cervical cancer. Cervical cancer is the second most common cancer in women and 70% of these cases are traceable to infections with HPV.

The vaccine will have the additional advantage of covering for other diseases caused by HPV, such as cancers of the vulva, vagina, penis, anus, and throat.

OBESITY EPIDEMIC; A call to action in Nigeria

Nigerians have moved from one extreme of the malnutrition spectrum to another. Time was when majority of Nigerians used to be undernourished with infants and under five children being the worst hit. But with changing trend in lifestyles, we have started witnessing an epidemic of obesity. A study carried out by chukwuonye I.I, et.al, in Nigeria (2013) lay credence to this fact. In that study the prevalence of overweight individuals ranged from 20.3% to 35.1%, while the prevalence of obesity ranged from 8.1% to 22.2% and other researchers in 2014 C. I. Okafor et.al revealed that 31% are overweight and 17% are obese in urban region while S. N. Akorolo-Anthony revealed that prevalence of obesity among urbanized adult Nigerians by gender for overweight men is 42% and women is 32% and for the obese men is 15% and women is 42%. Their conclusion was that the prevalence of overweight and obese individuals in Nigeria is of epidemic proportion in the urban areas. This has also come with its downside of increasing  incidence of diabetes, hypertension, stroke, heart attacks, sudden death and other cardiovascular diseases among the most productive persons in the society.
Overweight and obesity are known risk factors for diabetes and heart diseases and certain cancers. This trend is not likely to abate until we make changes to the way we live our lives, the foods we eat and the state of our physical health.
A recent study in the U.S. by Randy Dotinga an HealthDay Reporter revealed that while Americans are getting fatter, their average height remained the same, children are not immune to this trend. This is significant because any weight gain significantly increases the body mass index(BMI). The BMI is a rougher estimate of a person’s body fat using height and weight measurements. The BMI classifies people into different categories such as normal, overweight and obese. The BMI is a good indicator of overall risk for variety of diseases including heart diseases and diabetes.

Although there are many ways to fight obesity which includes: medications, surgery, dieting and physical exercises, there are generally no easy way or foolproof method to manage it. It has been shown that this short term measures do not work as any lost weight usually rebounds after a few years. We have to recognise obesity for what it is, a chronic disease that requires a concerted effort and more sustainable ways for it’s management. It’s management should therefore be a lifelong commitment to proper dietary habits, increasing physical activity, regular exercises and healthy living. The goal of management should not be to achieve an ideal body weight but rather to achieve and maintain a healthier weight. Any modest weight loss has been shown to be beneficial.

World Breastfeeding Week

World Breastfeeding Week: WHO infographics for the World Breastfeeding Week 2016

ERADICATION OF CERVICAL CANCER

There has been increasing incidence of cervical cancer in Africa.  Various screening programmes aimed at detecting the cancer at an early stage when it is easily treatable have been mounted in the past. Though some successes were recorded the cost concerns have been a major issue. It is in view of this that a programme is being proposed to address the challenge and offer coverage on a large scale in a cost effective manner. This particular programme is aimed at reducing the incidence of cancer through vaccination particularly for pubertal girls and boys who have not become sexually active. The main organism targeted is the Human Papilloma Virus (HPV). HPV has been implicated as the causative organism in about 80% of cervical cancer cases.