Prohibitive costs are preventing an important vaccine from reaching an estimated 260 children born with HIV daily in South Africa.

Prevenar, a vaccine manufactured by drug giant Wyeth Pharmaceuticals, can dramatically reduce the number of deaths from pneumonia and meningitis - both common opportunistic infections among HIV-infected children - but is well beyond the budgets of public healthcare programmes.

Also known as pneumococcal diseases, pneumonia and meningitis kill about one million children yearly despite the fact that they are among the easiest diseases to prevent, according to the World Health Organisation (WHO).

"While the drug is vital in preventing AIDS-related infections in children, it is currently only available to people with [access to] private healthcare," Johann Van den Heever, national immunisation programme manager in the Ministry of Health, told IRIN/Plusnews.

The drug currently costs private-sector pharmacists US$64 a shot, but added mark-ups bring the retail price to $262 for the prescribed triple injection of the vaccine.

South African toddlers are already being vaccinated against seven diseases, including diphtheria, tetanus, polio, and hepatitis-B, as part of the government's national immunisation programme, at around $14 per shot. Prevenar would be a welcome addition, said Van den Heever, were it more affordable.

Wyeth officials maintained they were dedicated to doing their part to make the vaccine more widely available in South Africa as well as other developing countries.

The company's medical director, Nini Ramsamy, confirmed that "in collaboration with relevant partners, Wyeth hopes to bring the vaccine to the world's most vulnerable populations through an affordable and sustainable plan that is reflective of global economic and market conditions".

Van den Heever said Prevenar had been available across the globe since 2005 to "a fortunate few people", but stressed the need for a speedier process in making it more affordable to those relying on the public health sector.

Prevenar is available in 74 countries, 16 of which have already included it in their immunisation programmes. With the exception of Mexico, all of these are developed nations with relatively low HIV-infection rates.

The WHO says pneumonia and meningitis are two of the main secondary causes of death among patients with compromised immune systems and kill between 700,000 and 1 million children each year, most of whom live in developing nations.

Supporting the WHO findings, Shabir Madhi, co-director of the respiratory and meningeal pathogens research unit at the University of the Witwatersrand, in Johannesburg, said HIV-positive children were up to 40 times more likely to contract the illnesses than children who were not.

"So you can see why this drug would be a valuable addition to immunisation programmes in countries like South Africa, where an estimated five to six percent of all kids born are not only infected with the HI virus, but also account for 75 percent of pneumococcal diseases," Madhi told IRIN/PlusNews.

Madhi evaluated Prevenar through a clinical trial in Soweto, a township on the outskirts of Johannesburg, involving 40,000 babies, 2,500 of whom were HIV-positive. The vaccine was found to reduce the risk of pneumococcal disease in HIV-positive babies by 65 percent, and by 85 percent in babies without HIV.

Madhi has urged government health officials to negotiate with big pharmaceutical firms to reduce the prices of important drugs and vaccines like Prevenar, as well as to look to donors and philanthropic organisations for financial assistance in making them more widely available.

However, Van den Heever noted that while the Global Alliance for Vaccines and Immunisation, a nongovernmental organisation, was set to roll out a Prevenar vaccination programme in Kenya and Gambia, for instance, South Africa did not qualify for assistance because "our gross national income is more than $1,000 per capita".

Prevenar is currently the only proven, commercially available vaccine against pneumococcal diseases.