‘Safe, tolerable’ — Scientists publish results of human trial of Lassa fever vaccine

Some scientists have published results of the human trial of MV-LASV, a Lassa fever vaccine.

According to the results published in The Lancet, the trial involved 60 healthy adults aged 18 to 55 years and was conducted at a single site at the University of Antwerp, Antwerp, Belgium.

It was said to have consisted of two stages — an open-label dose-escalation stage and an observer-blinded, randomised, placebo-controlled treatment stage.

Participants in the dose-escalation stage were assigned to two groups, one receiving a low-dose and another receiving a high-dose.

“Participants in the double-blinded treatment stage were randomly assigned in a 2:2:1 ratio to receive low dose, high dose, or placebo,” the researchers wrote.

The scientists said their goal was to find the rate of solicited and unsolicited adverse events up to study day 56 in all participants who received at least one dose of the vaccine.

An adverse event is any unexpected medical occurrence in a patient who was administered a pharmaceutical product and which does not have a causal relationship with the treatment.

“Most adverse events occurred during the treatment phase, and frequencies of total solicited or unsolicited adverse events were similar between treatment groups. Adverse events were mostly of mild or moderate severity, and no serious adverse events were observed,” the researchers wrote.

“MV-LASV showed an acceptable safety and tolerability profile, and immunogenicity seemed to be unaffected by pre-existing immunity against the vector. MV-LASV is therefore a promising candidate for further development.”

Reacting to the development, Ifedayo Adetifa, director-general of the Nigeria Centre for Disease Control (NCDC), said the agency welcomes the trial given that it will respond to record numbers of Lassa fever cases in 2023 already.

“As the editorial surmises, results from next phase trials in places like Nigeria will be key,” he said.

“It is critical to take forward the lessons from COVID19. Early community engagement is essential ahead of Lassa fever trials and as part of demand creation for successful vaccines. NCDC is happy to continue to work with partners such as CEPI vaccines to ensure this happens.”

So far in 2023, the NCDC has recorded 676 cases of Lassa fever and 109 deaths across the country.