A Phase 1B, Safety and Immunogenicity Study of a Lassa Fever Vaccine, ChAdOx1LassaJ, in Healthy Volunteers aged 18 – 55 Years in Ghana.

December 26, 2024| Ongoing Project | Reading time: 8 min

Introduction

Kintampo Health Research Centre (KHRC) has launched this important two-year study to test the safety and effectiveness of a new Lassa fever vaccine developed by the University of Oxford. This study, sponsored by the University of Oxford and funded by the Coalition for Epidemic Preparedness Innovations (CEPI), will recruit healthy participants aged 18 to 55 years. This study could lead to the roll-out of a life-saving vaccine that saves lives and protects millions of people from the harmful effects of Lassa fever.

Investigators

Dr. Seyram Kaali, Dr. Samuel Harrison, Dr. Anthony Ibrahim Siibu, Dr. Felicia Serwah, Dr. David Dosoo, Mr. Francis Mensah Kornu, Mr. Zakariah Buwah, Mr. Kingsley Kayan, Mr. Elisha Adeniji.

Background

Lassa (LASV) is a zoonotic arenavirus and a leading cause of haemorrhagic fever globally. The Lassa fever virus is prevalent in rodents (Mastomys Natalensis) and is endemic to many West African countries. There have been documented cases of Lassa fever in Nigeria, Mali, Ghana, Benin, Guinea, Sierra Leone, Togo, Cote D’Ivoire and Liberia. Human infection may be acquired through ingestion or inhalation of rodent excrement or through eating the meat of a contaminated animal. It can also be acquired by human-to-human transmission through contact with infected bodily fluids. It has been identified as an emerging outbreak pathogen by the World Health Organization and the UK Health Security Agency classifies it as a high consequence infectious disease.

Lassa fever is caused by a virus that poses a threat to a population of approximately 60 million people living in West Africa. Whilst the majority of individuals who develop it only have mild symptoms, for some it can be fatal. The virus is carried by a common rodent within West Africa which passes the disease to other rodents, their offspring and can also pass it to humans on occasion. This may be due to accidental exposure to rodent’s excrement, or through eating the meat of a contaminated animal. It is also possible for it to be spread from human to human through contact with infected bodily fluids. This has led to cases occurring in countries far away from West Africa. Whilst it is not fully understood why some individuals get severe disease and others only suffer from mild illness, in certain groups, such as pregnant woman and their unborn babies, the disease is always serious. Additionally, long term consequences such as hearing loss and balance problems can affect individuals who recover from the illness, irrespective of how unwell they were with the initial infection.

Given the significance of the infection, the potential long-term consequences for the survivors and number of people at risk of this disease, it is important we find a vaccine to help protect against the disease.

Objectives
The main objectives of this study are:
1. To assess the safety and tolerability of ChAdOx1LassaJ candidate vaccine in healthy volunteers aged 18 – 55 years.
2. To assess how the immune system of healthy adults aged 18 to 55 responds to the ChAdOx1LassaJ vaccine.

Study Methodology
This study will recruit 51 healthy adults to test the ChAdOx1LassaJ vaccine. Participants are randomly divided into groups, and the trial uses a placebo for comparison. The first stage will include six (6) participants (Cohort A). After that, 45 more participants (Cohort B) will join in three different groups:

Group 1 (up to 20 participants): This group will receive two doses of the Lassa vaccine, 12 weeks apart.

Group 2 (up to 20 participants): This group will receive one dose of the Lassa vaccine followed by a saline placebo injection,12 weeks later.

Group 3 (5 participants): They will receive one dose of the vaccine followed by a placebo injection 12 weeks later.

Each participant will be monitored for a year to ensure the vaccine is safe. Regular follow-up visits will include blood tests to check how their immune systems respond to the vaccine.

Expected Outcomes
The study is expected to show whether there are any expected or unexpected side effects after people receive the ChAdOx1 LassaJ vaccine. It will also check how the body's immune system responds to the vaccine, both through antibodies (a part of the immune system that fights infections) and the actions of immune cells.

Funder
Coalition for Epidemic Preparedness Innovations (CEPI)

Sponsors

University of Oxford

Study Duration
Two (2) Years