Malaria is a disease which was traditionally associated with swamps. The physicians of several ancient civilisations were intrigued by this fever, which debilitates a person in intervals, results in an enlarged spleen, and seen predominantly among people who live near marshlands.
Till the time of the Germ Theory, which was developed and refined by Louis Pasteur and Robert Koch in the nineteenth century, it was hypothesised that malaria is a result of ‘bad air’ from the swamps. The discovery of the malarial parasite, and its transmission through mosquitos, allowed us to have a shot at elimination of malaria.
But more than a century after Sir Ronald Ross got the Nobel Prize for discovering the transmission of malaria in birds, we are nowhere close to controlling the disease in a vast majority of tropical countries.
The quest for a Malaria vaccine has been on for a very long time, with very limited success. Therefore, the news of a Malaria vaccine being approved by the World Health Organization (WHO) for use in areas with moderate-to-severe transmission, was met with a lot of excitement in global health circles.
It also generated a lot of positive press in India, which is still a large contributor to malaria mortality and morbidity. Before triumphant messages on eradication of malaria, we need to temper our expectations based on the fine print that comes along with the vaccine.
The vaccine approved by WHO is called RTS,S/AS01, and is being produced as Mosquirix by GlaxoSmithKline (GSK). It is given as three doses between 5 and 17 months of age, with a fourth dose one-and-a-half years later. It is actually a vaccine which was developed more than three decades ago, by GSK. It entered clinical trials in 2001, with the help of PATH and Bill & Melinda Gates Foundation (BMGF).
The ability of the vaccine to prevent malaria incidence was low, but it could bring a moderate reduction of severe infections, and deaths among children. The vaccine received a favourable opinion from the European Medicines Agency in 2015, paving way for an evaluation by the WHO. Besides, Gavi-the vaccine alliance, Unitaid, Global Fund, etc. led a select rollout of the vaccine in three countries in Africa which suffer from high transmission rates of Malaria: Kenya, Ghana and Malawi.
This was done by incorporating the vaccine to existing immunisation programmes, and continuing with existing interventions to reduce malaria incidence. The operational aspects of the vaccine were supposedly very encouraging, with the logistics being much simpler as compared to Insecticide Treated Bed-Nets to reduce mosquito bites, and source reduction activities for mosquito control.
But there are several challenges between now and a wider vaccine rollout across countries which are endemic to malaria. The vaccines show a 30 percent effectiveness in reducing the incidence of severe malaria, even in areas with high usage of insecticide treated bed nets. Whether it's acceptable for governments is something which needs to be seen.
At approximately $5 per dose, it is going to cost a significant amount of money to vaccine all the eligible children. We also need clarity on how to mobilise these finances, considering the fact that almost all the malaria endemic countries fall into the low-income category. GSK has promised to donate 10 million doses to the vaccination programme, but we need commitments much more than this to meet global vaccination targets.
Another worry is that the focus on vaccination will take away the relative importance given to other interventions to contain the threat of malaria. Already the financing available to mosquito control activities, rapid diagnostic tests, and chemoprophylaxis is strained in several developing countries, and is being funded mainly through external grants. The general perception that vaccines are ‘quick-fixes’ can certainly place the other less glamorous public health measures in a difficult situation.
Even without the vaccine, India has been doing a remarkable job in malaria control. According to the World Malaria Report 2020, the country reported a 71 percent decline in malaria cases and a 73 percent reduction in malaria mortality between 2000 and 2019. Bulk of the case load, and deaths are now contributed by Odisha, Chhattisgarh, Jharkhand, Meghalaya and Madhya Pradesh. Even the number of districts in which malaria is endemic has come down significantly in the last two decades.
Therefore, India should be looking at a sharp targeted rollout of the vaccine based on the data on disease transmission in districts. Besides, the current strategy based on the National Framework for Malaria Elimination should be continued, and strengthened. Even the new malaria vaccine has an India connection. PATH, GSK and Bharat Biotech (BBIL) has announced that the latter will be the sole producer of the vaccine from 2029 after execution of the product transfer agreement. This may help to reduce the price further, and ease up supply issues for India.
The RTS,S vaccine is moderately effective against Plasmodium falciparum, the deadliest malarial parasite. In addition to this, WHO has stated that the safety profile of the vaccine is good, and it can be used along with other interventions to control malaria. A modelling-based study has suggested that the vaccine can potentially save the lives of 23,000 children, and it is a significant number for a disease which kills almost half a million people every year.
Therefore, while malaria vaccine is indeed a great news considering the disease’s impact on human lives, and the global economy, there is a long way to go before we declare victory over malaria.
Philip Mathew is a physician, public health consultant, and doctoral student at Karolinska Institutet, Stockholm. Twitter: @pilimat.
Views are personal and do not represent the stand of this publication.