New vaccine set to ease huge economic burden of malaria in Kenya

Last week GlaxoSmithKline (GSK) announced success with its anti-malaria vaccine, RTS,S. To many Kenyans, it meant an end to suffering and loss of lives to the disease that ravages most parts of sub-Saharan Africa.

But to the government, which is heavily short of resources to finance its budget obligations, this development could mean more than that.

Like many sub-Saharan Africa nations, the economic burden of malaria is huge and preventive vaccines such as that developed by GSK would help ease budgetary pressure.

Industry data show that malaria costs the country about Sh10 billion annually—indicating the economic gain that would come with effective use of the drug.

A new research published by the respected Malaria Journal 2013, says the economic cost of malaria in Kenya stands at about $109 million (Sh9.17 billion) annually, excluding costs associated with productivity loss due to death.

According to the study titled: The economic costs of malaria in children in three sub-Saharan countries: Ghana, Tanzania and Kenya, the economic cost of malaria jumps to $250.7 million (Sh21 billion) annually when the cost associated with productivity loss due to death is captured.

“Malaria exerts a significant economic burden on health care providers and households,” the study says.

According to the current Kenya Malaria Indicator Survey (MIS), malaria prevalence (likelihood of getting the disease) in Kenya is highest in the lake region at 38 per cent. Counties most affected in the region include Homa Bay, Kisumu, Migori, Siaya, Busia and Kakamega.

This is followed by the coastal and highland regions, where prevalence is at four and three per cent respectively.

The report also shows that children in rural areas are more than twice likely to get malaria than those living in urban centres.

In addition, the World Malaria Report estimates that there are approximately eight million suspected malaria cases in Kenya. This compares to about 12 million in Uganda, three million in Rwanda and 19,000 cases in Tanzania.

Due to the magnitude of malaria cases reported in Kenya, the disease exerts pressure on the country’s already limited financial resources. The government spends a lot of money buying treatment drugs, bed nets and insecticides used to control the disease. This money would be diverted to other development initiatives like education and infrastructure growth.

Malaria also poses a threat to Kenya’s chances of achieving the fourth millennium development goal, which seeks to reduce child mortality (deaths among children below five years).

In addition, malaria prevalence is high among children from poor households where most people rely on little income generated daily through manual work. Mothers cannot go out to work because they are taking care of the sick.

The time spent by these women looking after sick children at home or in hospital instead of working greatly reduces family income, further increasing poverty levels in the country.

Latest results from the ongoing phase three trials of the malaria vaccine candidate hold hope for the country and millions of families with children below five years in Kenya.

The results showed that 18 months after receiving the RTS,S vaccine, malaria cases reduced by almost half (46 per cent), in young children between five to 17 months.

Over the same period, malaria cases in infants between six to 12 weeks were reduced by about a quarter (27 per cent).

The results also stated that for every 1,000 children of five to 17 months who were vaccinated, an average of 941 malaria cases were prevented.

Similarly, 444 cases of clinical malaria were averted for every 1,000 infants between the ages of six weeks to 12 weeks that were vaccinated.

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The efficacy, safety and quality of RTS,S has been tested in Africa for more than 10 years. “We are now in the final stages and we expect that the malaria vaccine will be ready for use by 2015,” says Dr Moses Alobo, the Medical Director of GlaxoSmithKline (GSK) in Kenya.

The GSK and PATH Malaria Vaccine Initiative (MVI) is conducting the vaccine trials together with research centres in seven African countries. The three sites in Kenya are Siaya, Kilifi and Kombewa, which are co-ordinated by the Kenya Medical Research Institute (Kemri) centres.

Dr Simon Kariuki of Kemri –CDC notes that the results were encouraging. “Despite having effective interventions such as bed nets that prevent infections and drugs that cure the disease, the burden of malaria in young children is still high. A vaccine is thus an ideal addition that would significantly reduce the cases,” says Mr Kariuki, one of the principal investigators in the RTS,S vaccine trials in Africa.

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He notes that diseases such measles and small pox are no longer threats to public health as vaccines targeting them now exist.

“We believe that with a vaccine, our fight against malaria will be enhanced and we will actually begin preparing for its eradication;” says Dr Alobo. He adds that RTS,S would significantly reduce the amount of money channelled towards malaria control in Kenya.

Based on the results, researchers noted that the efficacy of the vaccine reduced slightly with time. For instance, preliminary trial results in 2011 showed that within the first year (12 months), RTS,S offered a 56 per cent protection against malaria to children of five to 17 months who had been vaccinated. But this protection reduced to 46 per cent after 18 months, based on the latest results of the phase three trials.

“This is not unusual in the field of vaccine research. We do have vaccines that have a life line, such as yellow fever which lasts for 10 year after which one needs to be vaccinated again,” says Dr Kariuki.

Dr Alobo notes: “And this is why we are now testing the effect of a RTS,S booster dose given to children who are 18 months old after receiving the first dose of the vaccine. We would like to determine whether it will prolong the immunity of the vaccinated children against malaria.”

The results of this trial will be out in 2014.

But even with its current efficacy levels, he notes that the vaccine coupled with other malaria control interventions will still significantly reduce the disease in Kenya.

The current phase three trial results also showed that the malaria vaccine efficacy in older children was greater than in infants.

“This may be due the fact that the immunity of infants at six to 12 weeks was still developing and thus not as robust as those of older children who also received the malaria vaccine,” says Dr Kariuki.

He adds that other childhood vaccines, also given to those between six to 12 weeks could have interfered with the efficacy of the malaria vaccine.

But even with the seemingly lower efficacy in infants, the vaccine is still of utmost importance for this age group. This is because compared to older children, malaria can lead to adverse effects in infants as their immunity is usually weak.

According to Dr Njagi Kiambo from the Ministry of Health’s Division of Malaria Campaign, the disease is spread by female anopheles mosquitoes that carry the parasite . “They usually get the parasite after feeding on blood of infected people. They then transmit the disease to others that they bite,” he says.

He notes that symptoms of malaria include fever, shivering, vomiting and headache. Doctors warn that if the disease is not treated early enough, it develops into severe malaria which leads to acute anaemia, making infected children lose consciousness, have convulsions and eventually die.

Rainfall and high temperatures increase the spread of malaria. This is because the former creates stagnant water bodies that offer breeding sites for the female anopheles mosquitoes to multiply, while the latter increase the rate at which they feed on human blood.

The RTS,S vaccine has been initially developed for use in children below five years living in malaria endemic regions in sub-Saharan Africa. It aims at protecting them from malaria caused by a parasite know as plasmodium falciparum which is the most deadly.

The vaccine is designed to prevent the parasite from infecting, maturing and multiplying in the liver once they get into the human body. It is after the successful completion of this stage, that the parasites usually enter the blood stream and affect red blood cells leading to disease symptoms.

The phase three trials – aimed at monitoring the efficacy, safety and potential side effects of the RTS,S malaria candidate vaccine are being conducted at 11 sites in seven African countries with different malaria transmission intensity and patterns. They are Kenya, Tanzania, Burkina Faso, Gabon, Ghana, Malawi and Mozambique.

The participants in the trials are children between five to 17 months and those of six to 12 months.

There were initial concerns about meningitis cases reported in a few children who had received the RTS,S vaccine. “We have investigated this and there is currently no scientific evidence showing that the cases were linked to the vaccine. So we are convinced that we have a safe product,” says Dr Alobo.

Dr Alobo notes that GSK is yet to set a price for the vaccine. The company, however, notes that the RTS,S pricing model will cover the cost of manufacturing the vaccine together with a small return of around five per cent which will be reinvested in research and development for other vaccines.

The GSK will also work with the Global Alliance for Vaccines and Immunisation (GAVI) whose funding mechanism has enabled many African countries — including Kenya— to provide childhood vaccines free of charge.

To date, GSK has invested more than $350 million and expects to invest another $260 million before the vaccine project is completed.

The Malaria Vaccine Initiative (MVI) has also received more than $260 million from the Bill and Melinda Gates Foundation to advance the development of RTS,S.

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