why-a-malaria-vaccine-candidate-has-raised-new-hope

Context: A malaria vaccine candidate has shown promise in phase 2b clinical trials, with high efficacy at 77%. The new vaccine candidate, called R21/Matrix M, is a modified version of RTS, S.

More on news:

  • In 2019, there were an estimated 229 million cases of malaria and 409 000 malaria-related deaths in 87 countries. 
  • Children under the age of 5 in sub-Saharan Africa accounted for approximately two-thirds of global deaths.
  • In 2019, India had an estimated 5.6 million cases of malaria compared to about 20 million cases in 2020 according to WHO. 
  • On World Malaria Day (April 25), WHO called on all people living in malaria-affected countries to “beat the fear”.
  • Covid-19 disruptions: In many countries, lockdowns and restrictions on the movement of people and goods have led to delays in the delivery of insecticide-treated mosquito nets or indoor insecticide spraying campaigns.

A phase 2 clinical trial 

  • It is conducted to evaluate the effectiveness and safety of a new drug or drug combination for a particular indication.
  • A phase 1 trial may recruit healthy volunteers for determining the maximum doses and dose ranges that should be administered.
  • Phase 2 is more focused on the therapeutic efficacy in a particular patient population to establish whether or not the drug may ultimately benefit patients and should be studied in a phase 3 trial.
  • Phase 2 trials are usually randomized, controlled studies evaluating the safety and efficacy of a drug for a particular condition.

About RTS, S 

  • It has been in development for more than 30 years by Walter Reed Institute of Research, GlaxoSmithKline and Bill and Melinda Gates Foundation with the PATH Malaria Vaccine Initiative.
  • This vaccine is designed to stop the Plasmodium falciparum malaria parasite from entering the liver and preventing the subsequent deadly blood stages. 
  • It targets the liver stage protein of the Plasmodium falciparum life cycle.
  • RTS,S is the only vaccine to reduce malaria in children. But it is not highly efficacious.

The new version: R21/Matrix M

  • Developed and produced by: R21/Matrix M has been developed by scientists at University of Oxford.
    • This vaccine was produced in the Serum Institute of India. The fact that the Institute was chosen as a location for manufacturing shows its tremendous ability to produce good quality
  • The phase 2b trial in 450 children in Burkina Faso found the vaccine safe with an efficacy of 77% over this period. 
  • Researchers have now started recruitment for a phase 3 trial to assess large-scale safety and efficacy in 4,800 children aged five to 36 months across four African countries.

Malaria

  • Malaria is a life-threatening disease caused by parasites that are transmitted to people through the bites of infected female Anopheles mosquitoes
  • It is preventable and curable.
  • Malaria is caused by Plasmodium parasites.
  • There are 5 parasite species that cause malaria in humans, and 2 of these species – P. falciparum and P. vivax – pose the greatest threat.
  • Symptoms: The first symptoms – fever, headache, and chills – may be mild and difficult to recognize as malaria. If not treated within 24 hours, P. falciparum malaria can progress to severe illness, often leading to death.
  • Malaria free status: Between 2000 and 2020, 24 countries reported zero indigenous cases of malaria for 3 or more years. 
    • This is the benchmark for the World Health Organization (WHO) certification of a country as malaria-free. Globally, 39 countries have achieved the milestone.

Source: https://indianexpress.com/article/explained/why-a-malaria-vaccine-candidate-has-raised-new-hope-and-what-went-into-its-making-7300888/