Breakthrough: 75% Effective Malaria Vaccine Discovered

[BillTre]

Several news sites (such as) have reported a 75% effective vaccine (phase 2 test) against malaria, a big killer of humans (greater than 400,000/year).
Could not find original report.
This will be important if it holds up.

 

[Ygggdrasil]

Could not find original report.

Pre-print available here: https://papers.ssrn.com/sol3/papers.cfm?abstract_id=3830681

High Efficacy of a Low Dose Candidate Malaria Vaccine, R21 in 1 Adjuvant Matrix-M™, with Seasonal Administration to Children in Burkina Faso

Abstract:

Background: Stalled progress in controlling Plasmodium falciparum malaria highlights the need for an effective and deployable vaccine. RTS,S/AS01, the most effective malaria vaccine candidate to date, demonstrated 55·8% (97·5% confidence interval [CI], 51-60) efficacy over 12 months in African children.

Methods: We conducted a double-blind, randomised, controlled trial of a low-dose circumsporozoite protein-based vaccine, R21, with two different doses of adjuvant, Matrix-M™ (MM), in children aged 5-17 months in Nanoro, Burkina Faso, a highly seasonal malaria transmission setting. Three vaccinations were administered at 4-week intervals prior to the malaria season with a fourth dose one year later. Vaccine safety, immunogenicity and efficacy were evaluated over one year.

Findings: 450 children were randomised to receive the R21/MM vaccine or a control rabies vaccine. R21/MM had a 43 favourable safety profile and was well-tolerated. At 6 months, 43/146 (29·5%) who received R21/MM with low44 dose adjuvant, 38/146 (26%) who received R21/MM with high-dose adjuvant, and 105/147 (71·4%) who received the rabies vaccine developed clinical malaria. Vaccine efficacy (VE) was 74% (95% CI, 63-82) and 77% (95% CI, 67-84) in the low- and high-dose adjuvant groups, respectively. At 1 year, VE remained high at 77% (95% CI, 67-84) in the high-dose adjuvant group. Participants vaccinated with R21/MM showed high titres of malaria-specific anti-NANP antibodies 28 days after the third vaccination, which were almost doubled with the higher adjuvant dose. Titres waned but were boosted to levels similar to peak titres following the primary series of vaccinations after a fourth dose administered one year later.

Interpretation: R21/Matrix-M appears safe and very immunogenic in African children, and demonstrates promising high-level efficacy.

Press release from Novavax (one of the vaccine manufacturers): https://ir.novavax.com/news-releases/news-release-details/malaria-vaccine-phase-2b-clinical-trial-results-published

Similar vaccine technology is being used by Novavax in the development of their protein subunit COVID-19 vaccine.

 

[berkeman]

R21 in 1 Adjuvant Matrix-M™

That's a catchy name! I don't blame them for Trademarking it.

Sounds like promising news.

 

[Ygggdrasil]

Researchers have shown that an mRNA vaccine can fully protect mice from malaria:

Messenger RNA expressing PfCSP induces functional, protective immune responses against malaria in mice
https://www.nature.com/articles/s41541-021-00345-0

Abstract:

Human malaria affects the vast majority of the world’s population with the Plasmodium falciparum species causing the highest rates of morbidity and mortality. With no licensed vaccine and leading candidates achieving suboptimal protection in the field, the need for an effective immunoprophylactic option continues to motivate the malaria research community to explore alternative technologies. Recent advances in the mRNA discipline have elevated the long-neglected platform to the forefront of infectious disease research. As the immunodominant coat protein of the invasive stage of the malaria parasite, circumsporozoite protein (PfCSP) was selected as the antigen of choice to assess the immunogenic and protective potential of an mRNA malaria vaccine. In mammalian cell transfection experiments, PfCSP mRNA was well expressed and cell associated. In the transition to an in vivo murine model, lipid nanoparticle (LNP) encapsulation was applied to protect and deliver the mRNA to the cell translation machinery and supply adjuvant activity. The immunogenic effect of an array of factors was explored, such as formulation, dose, number, and interval of immunizations. PfCSP mRNA-LNP achieved sterile protection against infection with two P. berghei PfCSP transgenic parasite strains, with mRNA dose and vaccination interval having a greater effect on outcome. This investigation serves as the assessment of pre-erythrocytic malaria, PfCSP mRNA vaccine candidate resulting in sterile protection, with numerous factors affecting protective efficacy, making it a compelling candidate for further investigation.

Press release from the Walter Reed Army Institute of Research: https://eurekalert.org/pub_releases/2021-06/wrai-mvy061721.php

 

[Ygggdrasil]

The WHO approved the first vaccine against malaria:

The world's arsenal against malaria just got a fancy new bazooka. But it's not the easiest weapon to deploy, it only hits its target 30 to 40% of the time, and it's not yet clear who's going to pay for it.

The weapon in question is the RTS,S vaccine from GlaxoSmithKline, which on Wednesday got the green light from the World Health Organization for widespread use.

This is not only the first authorized malaria vaccine, it's also the first vaccine ever approved for use against a parasitic disease in humans.

The recommendation comes after RTS,S showed positive results in a pilot program in Ghana, Kenya and Malawi. The vaccine cut malaria cases by 40% and reduced hospitalizations of the potentially deadly disease by nearly a third.

(NPR)

This vaccine is different than the vaccines from Novavax or the mRNA vaccine mentioned earlier in the thread. Rather, the vaccine is an older vaccine which won regulatory approval from the EMA in 2015. WHO approval comes after positive results from a pilot program in Ghana, Kenya and Malawi that has treated more than 800,000 children since 2019.

See also the official WHO press release: https://www.who.int/news/item/06-10...breaking-malaria-vaccine-for-children-at-risk