/ 26 November 2007

Pneumonia vaccine too expensive

One in five of the tens of thousands of young children who die each year in South Africa probably suffocate to death, drowning from pus-filled lungs as a result of pneumonia. Yet more than two-thirds of these deaths could be prevented if all children under five were given a vaccine that protects against the most common bacterial cause of pneumonia -- the pneumococcus.

One in five of the tens of thousands of young children who die each year in South Africa probably suffocate to death, drowning from pus-filled lungs as a result of pneumonia.

Yet more than two-thirds of these deaths could be prevented if all children under five were given a vaccine that protects against the most common bacterial cause of pneumonia — the pneumococcus (Streptococcus pneumoniae). But the vaccine costs more than R1 000 for the full course and is used only in the private sector.

Research into a vaccine similar to the one commercially available found that it cut severe pneumococcal disease by 83% in HIV-negative children; this fell to 65% in HIV-positive children because of their weaker immune response to the vaccine.

Heather Zar from the Red Cross War Memorial Children’s Hospital says that for every death directly attributed to pneumonia, the condition contributes to the deaths of another two or three children. Children with HIV or who are HIV-infected are particularly vulnerable to lung disease.

In South Africa mortality among under-fives has been climbing as a result of HIV. Pneumonia and diarrhoeal disease are the two main killers and are among the most preventable illnesses. Almost half the children dying from pneumonia are malnourished, which compromises the child’s immune system, as well as retarding growth and development.

Children who are HIV-infected are about 10 times more likely to die from childhood pneumonia than children who are negative, while those who have HIV-positive mothers but themselves do not have the virus still have a greater chance of dying. For children in the latter group, the higher risk might reflect the inability of the mother to pass adequate antibodies on to her child during pregnancy or breastfeeding, as well as social and environmental issues, such as poverty, that often accompany — and sometimes are caused by — HIV infection.

Protecting children with a pneumococcus vaccine could have spin-offs outside the direct welfare and healthcare needs of the child. Mass immunisation of young children cuts the direct and indirect costs of treating children and reduces pneumonia among older people. The bacteria is carried in the nose — so children spread the disease among older family members.

Zar called for the implementation of the pneumococcal conjugate vaccine and for negotiations to drive down the price in developing countries. She pointed out that a study among children in Gambia found that total child mortality fell 16% as a result of vaccination.

But Zar also pointed out that many children’s lives could be saved with the use of the readily available, safe and cheap drug, cotrimoxazole. If given as a prophylactic to HIVpositive children, this prevents pneumonia from a fungus now known as Pneumocystis jiroveci (formerly carinii). Known as PCP, this is a common and devastating cause of pneumonia in HIV-infected children under the age of six months, resulting in death in almost half the cases. It is responsible for a quarter of deaths among young HIV-positive children.

The World Health Organisation says that more than a million deaths worldwide could be prevented by universal use of a pneumococcal vaccine and recommends it as a routine childhood vaccination in countries where child mortality is more than 50 per 1 000 children.

In South Africa in 2005 it was 66 per 1 000 children.