From VOA Learning English, this is the Health Report in Special English.
Most countries are now free of polio, but the disease remains a threat in some places including Nigeria.
Gregory Hussey is the director of the Vaccines for African Initiative at the University of Cape Town in South Africa.
"There's a worldwide move to eradicate polio in the next 5 to 10 years. The stumbling blocks in Africa are in fact [in] Nigeria where there's continued transmission of polio because of sub-optimal uptake of polio vaccine. And I'm sure you're aware of the fact that the people refusing to immunize their children for a list of reasons – religious, political, etcetera, etcetera."
The World Health Organization says after polio vaccination campaigns were interfered with in northern Nigeria several years ago, the virus there spread all the way to Ethiopia. Professor Hussey also says continued outbreaks of measles are another example of vaccination system failure.
"With our porous borders in Africa disease can spread from one place to another place, especially if children are not being immunized properly."
He says while the United Nations and other international agencies have campaigns supporting immunization, African lacked a home-grown program.
"We started this Vaccines for Africa Initiative precisely to try to make people more aware of issues around vaccine and immunization practices. And this includes not only the individuals who are delivering the vaccines, the healthcare workers, but also the policymakers, as well as communities, who should be receiving the vaccines."
Gregory Hussey says a major problem is the cost of the vaccines. For example, more countries are starting to offer vaccines against pneumonia and diarrheal diseases, which are two of the leading killers of young children.
"You're looking at pushing up the price from a few dollars up to about $58. And that's way beyond the per capita health expenditure of most countries in Africa, which probably is around about $10 to $20 per person"
An international public-private partnership, the GAVI Alliance, plays a major role in helping developing countries offer vaccines. GAVI negotiates with drug companies to lower the cost of medicines. But Mr. Hussey warns that low cost vaccines will not last forever.
"Once they sort of graduate from GAVI they still will have to purchase those vaccines. So there are a number of countries that are going to graduate in the next year or two and that's a problem for them. Because how to they then fund the supply of those vaccines?"
He says some countries with enough money to pay for the vaccines have not made the health of children an important goal. Researchers at the University of Cape Town say African leaders must be held accountable for meeting agreed country immunization targets and honoring international commitments.
Last November, the first International African Vaccinology Conference was held in Cape Town. Participants proved the Cape Town Declaration among other things. It calls for strengthening childhood immunization programs, supporting regional cooperation, and strengthening purchase power by grouping resources.