When it comes to killing humans, no other animal comes close to mosquitoes. This observation by Bill Gates has often been quoted in most discussions on this globally disliked parasite-carrying insect. Much like the unending suffering endured by the people in the malaria infested regions, scientists too have been troubled for decades trying to develop a vaccine. It had to after all be against a mosquito bite that can deliver the parasite right to the liver and stay armed with an evolved ability to even evade the human immune system.
But then, just over the last two years, the World Health Organisation (WHO) has approved two vaccines against malaria. It is perhaps with good reason that Dr Tedros Adhanom Ghebreyesus, director general at the WHO sees a near fructifying of a dream that he once held as a malaria researcher for a safe and effective vaccine against malaria.
While, this is indeed a moment to rejoice especially for children, who could be administered this vaccine, scientists and researchers remind that India and the adult population globally will need to wait as these are largely vaccines for use in the African region and for children.
“In the Indian context one of the predominant malarial parasites is plasmodium vivax (p.vivax) against which a vaccine is still evasive,” says K V Balasubramaniam, an independent consultant on vaccines and the former managing director of Indian Immunologicals.
According to studies, close to 50 per cent of all malaria cases are due to p.vivax and the epidemiological landscape in India is a bit more complicated considering that there is also an overlapping in the distribution of p.falciparum and p.vivax and it is not as if these are mutually exclusive pockets. And that is not all, there are other species also such as plasmodium ovale and plasmodium malariae.
Malaria remains a concern for India. According to the National Health Profile 2022 released by the Central Bureau of Health Intelligence, “In 2021, in India, in terms of burden of diseases, dengue and malaria emerged as the toppers.” And while this acute parasitic illness is caused mainly by Plasmodium falciparum or Plasmodium vivax in India, “between 2017 and 2021 there is fluctuation in burden of this morbidity with a definite drop in number of deaths associated with it, from 194 deaths in 2017 to 80 deaths in 2021. In 2021, maximum number of malaria cases were reported from Chhattisgarh (29,455) followed by West Bengal (28,841), while maximum number of malaria-associated deaths were reported from Chhattisgarh (34).” Also, according to the World Malaria report 2022, India accounted for 79 per cent of cases and 83 per cent of all malaria deaths in the South East Asia region.
At a global level, a fact sheet on malaria released by the WHO in March this year points out that globally, COVID-related disruptions led to about 13 million more malaria cases and 63,000 more malaria deaths during 2020-21. In 2021 the Africa region was home to about 95 per cent of all malaria cases and 96 per cent of deaths. Children under 5 years of age accounted for about 80 per cent of all malaria deaths in the region. Four African countries accounted for just over half of all malaria deaths worldwide: Nigeria (31.3 per cent), the Democratic Republic of the Congo (12.6 per cent), United Republic of Tanzania (4.1 per cent) and Niger (3.9 per cent). The news on vaccines is therefore a step towards an ability to cope with the malarial challenge better, there are challenges ahead with some even arguing that a three dose vaccine, as the latest vaccine approved by the WHO requires, could come with its own set of challenges as ensuring compliance is not easy with multiple doses but then it is possible that since it is vaccine for children, the parents may comply a bit more easily.
