Malaria vaccine tests have been successful

The ongoing clinical trial of Malaria vaccine ( PfSPZ) in the country has shown that the immunising agent can provide protection against the disease, investigators have reported. 

The development provides hope in the fight against the deadly disease which has continued to threaten the lives of pregnant women and children.

The news came as a report published in the Lancet Infectious Diseases this week showed that the Sanaria's Pf- SPZ vaccine confers significant protection against natural Malaria infections in Mali.

According to Ifakara Health Institute (IHI) which conducts the clinical trial at its facility in Bagamoyo, the PfSPZ vaccine has been proven to be safe and that the ongoing test has shown that it can provide protection against sporozoites.

The IHI Principal Investigator, Dr Said Jongo, told the ‘Sunday News’ yesterday that, the trial conducted earlier in the country was meant to establish the safety and tolerability of the vaccine. Dr Jongo explained that in 2014/2015 the study was conducted on PfSPZ vaccine and the volunteers were provided with different doses which produced several results. He said some volunteers were provided with 135,000 PfSPZ doses while others were given 270,000 PfSPZ doses.

"The results showed that the vaccine can provide protection against Malaria parasites but the efficacy was low" Dr Jongo said. He said that the results led to the designing of new trial to test higher doses whereby in 2015/2016 the first vaccine trail in adolescents and children was conducted in Tanzania.

Dr Jongo noted that the vaccine trial for children based only on safety and it established a very good safety and tolerability profile in the group. He, however, noted that the PfSPZ vaccine is still under trial in the country and it was yet to be approved by the World Health Organisation (WHO) and the Ministry of Health, Community Development, Gender, Elders and Children.

Earlier, the Chief Executive Director of IHI, Dr Honorati Masanja, said that his organisation conducted the clinical trial on the safety of the PfSPZ vaccine to children between six months and 18 years. He said that the trial established that the vaccine was safe.

He said the Tanzania protocol was being used in Kenya and Equatorial Guinea to establish the safety of the vaccine. Dr Masanja noted that the investigator were also conducting a trial to establish whether people infected with HIV/AIDS can benefit from the vaccine.

“Earlier, the trial excluded people who were HIV positive, but they are now conducting study to establish whether the group can benefit from the vaccine,” Masanja said.

Investigators in Mali reported that Sanaria® PfSPZ Vaccine protected against natural infections of Plasmodium falciparum, the leading cause of malaria deaths and that protection was sustained for the 24 weeks of the study in an area of intense malaria transmission.

In the Mali study, five doses of PfSPZ Vaccine were administered to 44 subjects and saltwater placebo was given to 44 subjects.

The statement said that volunteers were followed for six months through the subsequent rainy season to determine the presence of malaria parasites in the blood. While a staggering 93 per cent of the placebo group had one or more infections, only 66 per cent of the vaccinated subjects acquired an infection and in those vaccinated subjects who became infected, the time to infection was delayed.

This represents 48 per cent protective efficacy by time-to-event analysis and 29 per cent efficacy by proportional analysis.

There were no differences in adverse events between the vaccinated group and the placebo group. Sanaria Founder and CEO, Stephen Hoffman, MD said, “These are extremely encouraging results as we have seen significant protection with a dosage regimen that we know to be sub-optimal.

“We are now building on the protective efficacy seen in this first, landmark study of efficacy of PfSPZ Vaccine in Africa in current clinical trials of PfSPZ Vaccine underway in Tanzania, Equatorial Guinea, Burkina Faso, Germany, the US and of course in Mali,” he said.

Professor Ogobara Doumbo, MD, PhD, Director of the Malaria Research Training Centre at the University of Bamako, Mali, said, “Many of us living in countries where people’s lives are devastated by malaria have been waiting for decades for a highly effective malaria vaccine. Over the past decade we have studied many experimental malaria vaccines in Mali. This is by far the best result we have ever obtained, Prof Doumbo said.

“These important results provide the evidence that protection against infection, not just disease, can be sustained for at least half a year.

This is clearly a cornerstone for us to finally home in on a PfSPZ Vaccine regimen that will provide high level, lasting protection to people living in malaria affected areas,” said Prof Marcel Tanner, President of the Swiss Academy of Sciences and Director Emeritus, Swiss Tropical and Public Health Institute.