London:

A new “high efficacy” malaria vaccine co-developed by the Serum Institute of India (SII) and the University of Oxford was officially rolled out on Monday when Cote d’Ivoire in West Africa became the first country to begin administering R21/Matrix-M.

The vaccine, which was granted World Health Organisation (WHO) approval last year, is said to have undergone a rigorous regulatory process and clinical assessment and was found to be highly effective and affordable. As a low-dose vaccine, it can be manufactured at speed and scale which is seen as critical to stemming the spread of the mosquito-borne disease.

“Reducing the malaria burden is finally within sight. Today’s start of the R21/Matrix-M vaccine roll-out marks a monumental milestone after years of incredible work with our partners at Oxford and Novavax,” said SII CEO Adar Poonawalla.

“At Serum, we believe that it is every person’s right to have access to affordable and essential disease prevention. That’s why we have committed to producing 100 million doses of R21, which will protect millions of lives and alleviate the burden of this deadly disease for future generations,” he said.

In anticipation of the roll-out, SII said it has manufactured 25 million doses of the vaccine and is committed to scaling up to 100 million doses annually. In keeping with its aim of delivering vaccines at scale and low cost, the Pune-headquartered company said it is offering the vaccine at less than USD 4 per dose.

“The roll-out of the R21/Matrix-M malaria vaccine marks the start of a new era in malaria control interventions with the high efficacy vaccine now accessible at a modest price and very large scale to many countries in greatest need. We hope that this vaccine very soon can be provided to all African countries who wish to use it,” said Professor Adrian Hill, Director of the Jenner Institute at Oxford University.

R21/Matrix-M was co-developed by the university and SII leveraging Novavax’s Matrix-M adjuvant technology. In December 2023, WHO granted it prequalification status after trials demonstrated that the vaccine was well tolerated, with a good safety profile, with injection site pain and fever as the most frequent adverse events.

Although the number of malaria-related deaths has fallen from 3,222 in 2017 to 1,316 in 2020 in Cote d’Ivoire, the deadly disease still kills four people a day, mostly small children, and “remains the leading cause of medical consultations”, according to the country’s Ministry of Health.

A total of 656,600 doses have been received, which will initially vaccinate 250,000 children aged between 0 and 23 months across 16 regions of Cote d’Ivoire. The R21/Matrix-M vaccine has also been authorised by Ghana, Nigeria, Burkina Faso and the Central African Republic.

R21 is the second malaria vaccine available in Sub-Saharan Africa following RTS,S and wide implementation of the malaria vaccines, in conjunction with existing prevention methods like bed nets, is expected to save tens of thousands of young lives each year. In total, 15 African countries are expected to introduce malaria vaccines with Gavi support in 2024, and countries plan to reach around 6.6 million children with the malaria vaccine in 2024 and 2025.

Dr Sania Nishtar, Chief Executive Officer of Gavi, the Vaccine Alliance, said: “Africa has borne the brunt of malaria for far too long, and Cote d’Ivoire has suffered more than most. With two safe and effective vaccines now available alongside other interventions, we can finally turn the tide against this killer disease.” John Jacobs, President and Chief Executive Officer, Novavax, added: “The introduction of the R21/Matrix-M malaria vaccine in Cote d’Ivoire marks a breakthrough in the fight to protect vulnerable children against a leading cause of death across the region while reinforcing our mission to create innovative vaccines that improve public health.”

(Except for the headline, this story has not been edited by NDTV staff and is published from a syndicated feed.)

A malaria vaccine — R21/MatrixM — developed by the University of Oxford, manufactured by the Pune-based Serum Institute of India and tested in a phase-3 trial at five sites in four countries — Mali, Burkina Faso, Kenya, and Tanzania — in Africa was recommended (but yet to be prequalified) by the WHO on October 2.

Three countries — Nigeria, Ghana, and Burkina Faso — have already approved the use of the vaccine to immunise children aged less than 36 months. According to the WHO, in 2021, there were 247 million malaria cases worldwide and 6,19,000 deaths. About 25 million children are born each year in countries with moderate to high malaria transmission.

The phase-3 trial was conducted in 4,800 children who were randomly assigned to receive either the malaria vaccine or a control (approved rabies vaccine) and neither the participants nor the people conducting the trial knew who got the vaccine and who did not. The five sites in the four countries where the trial was conducted have different malaria transmission intensities and seasonality. The participants received three vaccine doses four weeks apart, and a booster shot at the end of 12 months after the last dose. The primary vaccination was carried out prior to the malaria season in countries where malaria is seasonal or at any time of year in countries where malaria occurs throughout the year.

As per the results of the phase-3 trial that have been posted in a preprint server (preprints are yet to be peer-reviewed), the vaccine efficacy at the end of one year in children aged 5-36 months was 75% where malaria is seasonal and 68% where malaria is perennial. In children aged 5-17 months, who are more likely to die due to severe malaria, the vaccine efficacy was higher — 79% where malaria is seasonal and 75% where malaria is perennial. In children aged 18-36 months, vaccine efficacy was 73% where malaria is seasonal and 63% where malaria is perennial. “The vaccine efficacy was well maintained to 18 months with a single booster dose given 12 months after the primary series,” authors of the preprint write.

“Our findings are consistent with data from a recently completed phase IIb trial at the Nanoro seasonal site, where vaccine efficacy was 76% and 77% over one and two years of follow-up using a four dose (primary plus booster) vaccine regime in 5-17-month-old infants,” they note.

The higher vaccine efficacy in younger children (5-17 months) compared with older children (18-36 months) might be a “sign that the vaccine is less effective in people who have already been exposed to malaria” Matthew Laurens, a malaria vaccine expert at the University of Maryland School of Medicine told Science. And if that turns out to be true, then the vaccine might have “lower efficacy in areas with very high malaria incidence, where young infants are exposed at an early age”.

Waning efficacy

“There was some waning of efficacy over the first year of follow-up at both seasonal and perennial transmission sites, but a booster dose restored efficacy at the seasonal sites with a vaccine efficacy over 18 months of 74%,” says an Oxford University release.

The vaccine efficacy of R21/MatrixM is much higher than the first malaria vaccine — RTS,S/AS01 that has been recommended by the WHO in 2021 — which had a vaccine efficacy of 56% at the end of one year in children aged 5-17 months. According to the preprint, even after four booster shots of the RTS,S/AS01 vaccine, the efficacy was only 58% over five years.

The results indicate that the vaccine was more efficacious in places where malaria was seasonal than when it was perennial. The authors think that this may partly be due to timing of malaria episodes in countries with seasonal or perennial malaria. The study found that in sites where malaria was seasonal, 82% of malaria episodes in the first year were recorded in the first six months of follow-up, while only 26% of malaria episodes over the first year were recorded in the first six months at the sites where malaria is perennial. The vaccine efficacy is highest 14 days after the third dose and begins to slowly wane. Since the vaccination is carried out just before the beginning of the malaria season, the protection offered is higher when the disease is seasonal than when malaria occurs throughout the year. 

The authors claim that besides substantially reducing the number of clinical malaria cases, at 12 and 18 months, there was “significantly reduced” parasite load in children who received the vaccine (R21/Matrix-M). This suggests that the vaccine may help reduce malaria transmission, especially when combined with other strategies such as mosquito nets.

According to the WHO, the cost of the R21/Matrix-M manufactured by Serum Institute will be between $2 and $4 per dose. Serum Institute will produce “over 100 million doses a year”.