EXPLAINER: What you should know about New Oxford R21 Malaria Vacc!ne Nigeria Got

On Thursday, Nigeria launched a new malaria vaccine 18 months after the Federal Ministry of Health and Social Welfare provisionally approved it. Mohammed Ali Pate, the Nigerian Health Minister, said that the country had received more than 800,000 out of the one million doses it was expecting.

Nigeria procured the Oxford R21 malaria vaccine in partnership with the Vaccine Alliance, GAVI (the global vaccine group) and the United Nations Children’s Emergency Fund (UNICEF). Pate had told the media that the vaccine may not be enough but it would be administered to the recipients in Nigeria for free.

The R21/Matrix is special because, after several years of consistent research, it is the second vaccine to be approved for use by the World Health Organisation (WHO). Mosquirix (technically identified as RTS,S/AS01), the first vaccine approved by WHO for public use, only recently got a nod in 2021.

But what exactly are the vaccines and how do they even work? FIJ has broken down the science behind vaccines, specifically the matrix, after critically examining recognised literature about the vaccine.

HOW THE MALARIA VACCINE WORKS; WHAT’S INSIDE?

In the simplest form, vaccines leverage the human body’s ability to protect itself against familiar threats. With vaccines, medical professionals introduce a harmless version of a parasite into the human body. The body, in reaction to the intruder, creates a defence against that specific intruder so it can deal with it in subsequent intrusions.

That way, if the body is ever infected by the same parasite in the future, the body is prepared beforehand to handle the attack.

In the case of the malaria vaccines, both the R21 and the RTSS vaccines are designed to protect recipients from Plasmodium falciparum, the parasite responsible for most malaria cases in Nigeria.

At the core of both vaccines is the circumsporozoite protein (CSP). This protein is found on the surface of the malaria parasite during its early developmental stages when it infects the liver.

The very first form of the malaria parasite in the body is the sporozoite. This is what the vaccine is targeting.

By introducing this protein into the human body, the body is then equipped to handle the malaria parasite very early into its attack.

WHAT MAKES THE R21 SPECIAL?

The R21 vaccine has an ace up its sleeve. It has an adjuvant — a substance added to vaccines to increase immune response — called Matrix-M. This adjuvant has been documented to help the body create more antibodies at a higher level and modulate the body’s human.

Adjuvants have also been documented to be capable of reducing the number of vaccinations needed to immunise a patient.

Beyond this, R21 is cheaper to manufacture and consequently cheaper to purchase, making it the ideal option for low-income countries like Nigeria, according to Adrian Hill, a professor of vaccinology at the University of Oxford.

“Instead of this being nine or 10 (US) dollars, as with the original vaccine per dose, this is just under four dollars, and that makes a real difference in low-income countries. That’s why the development is really important because everyone sees this as an affordable vaccine,” Hill explained.

Most importantly, the new vaccines can be manufactured at scale. Matshidiso Moeti, WHO’s regional director for Africa, inferred this in a report by the BBC.

He said, “This second vaccine holds real potential to close the huge demand-and-supply gap. Delivered to scale and rolled out widely, the two vaccines can help bolster malaria prevention, control efforts and save hundreds of thousands of young lives.”

Both the R21 and RTS,S vaccines were found to be about 75% effective during clinical trials. WHO has also said there was no evidence that one vaccine worked better than the other since they haven’t been directly compared.

Nigeria has about 27% of the total number of malaria cases in the world. Also, about 31% of the total malaria-related deaths worldwide happen in Nigeria, according to UNICEF. Per a 2017 report by the Corporate Alliance on Malaria in Africa, Nigeria loses about $1.1 million to Malaria annually.

DOES THE VACCINE HAVE SIDE EFFECTS?

In the phase III trial with over 3,200 children across four African countries, the R21 malaria vaccine’s most common side effects were fever, pain at the injection site, swelling, loss of appetite and drowsiness, in that order.

A serious side effect, febrile convulsions (seizures with fever), was seen in 0.15% of cases within seven days.

At the end of the trial, however, the vaccine was passed off as safe and effective in reducing the risk of malaria infection.