Do we really need a malaria vaccine?

In October 2021, the WHO had approved the RTS,S/AS01 (RTS,S) malaria vaccine for administration in four scheduled doses for five-month infants to reduce the burden and severity of malaria in sub-Saharan Africa, and in other regions with moderate-to-high Plasmodium Falciparum malaria transmission.

At  the Asia-Pacific Leaders’ Conclave on Malaria Elimination on Monday, Dr VK Paul, member of NITI Aayog, congratulated South Asian and Pacific Region countries in achieving a significant decline in malaria cases. He stressed on the goal to make malaria history with a focus on working on most marginalised and vulnerable communities with an inter-sectoral approach. He said that India needed to work rapidly in developing a vaccine against malaria “in order to have additional arms” against the disease.

However, Dr Sanjay Rai, professor at the Centre for Community Medicine at AIIMS Delhi, said that  since India was not in a high endemic zone, a vaccine push might be a bit overambitious. Excerpts from an interaction:

Can a vaccine against malaria work in India?

India is in a lower endemic region now and we have less than 100 deaths being reported since the last two or three years. WHO had recommended a vaccine for Africa  during Covid based on a study meant for high and moderate endemic countries. The 95 per cent fatalities all over the world were from sub-Saharan countries, particularly in children. The fatalities were happening there due to Plasmodium Falciparum but in India it is not the major culprit behind the malaria cases. In India, the majority of states have reported Plasmodium Vivax and the vaccine is not effective against it. It will give some immunity against the parasite but Vivax is not a very severe variant. We are not in a high endemic zone so that is why vaccines are not recommended. In Africa, a large number of fatalities happened in children due to Plasmodium Falciparum. We have a mixed type of malaria parasites, with Plasmodium P Vivax being the majority.

Before rolling out any vaccine or any programme, we must do a cost-benefit analysis. WHO has done this assessment only in high burden countries where it is cost-effective. In low-burden countries, vaccination is not very cost-effective. Besides, for now only one vaccine has been approved.

Does Plasmodium P Vivax need a vaccination?

Not many deaths have been recorded, so it’s not considered a dangerous parasite. We really don’t have approved vaccines for low endemic countries. While WHO has approved vaccines for high burden countries, it is also facing a demand and supply mismatch.

How to tackle malaria then?

Many countries like Sri Lanka, Maldives and China, which were high burden countries, eliminated malaria only by control measures. If we adopt effective controls, it is possible to attain zero cases and fatalities. We need to work on source reduction and control breeding of mosquitoes, use bed nets and so on.

There are various control measures under the National Vector Disease Control programme. In fact, cases have been declining in India over the last 10 years. All malaria-related indicators like positivity rate, annual parasite incidence are gradually declining too. So we are moving in the right direction but there is a need to accelerate control measures.