Dengue fever is a potentially fatal viral infection transmitted by the bite of an infected mosquito. It mainly affects tropical areas, but with global warming it now also affects the Mediterranean basin.
“There have been outbreaks in the south of France and in Madeira”, explained Thursday to Keystone-ATS Blaise Genton, head of the Policlinic of tropical medicine, travel and vaccinations of Unisanté.
In Switzerland, it is one of the most frequent causes of fever when returning from a trip. The incidence of dengue has increased eightfold over the past twenty years. According to the WHO, the virus leads to two deaths per hour. The Covid pandemic has limited prevention and remediation measures, causing an upsurge in cases.
Current vaccine unsatisfactory
Currently, there is only one licensed vaccine against dengue fever and its antibody-inducing technology is unsatisfactory. But innovative technology could change everything, says Unisanté in a statement.
Developed in England by Emergex Vaccines, the PepGNP-Dengue vaccine works by killing infected cells rather than producing an antibody-based response like conventional vaccines. In the case of dengue, the antibodies are sometimes protective, but they can be aggravating in those who are re-exposed to the virus.
This new technology offers real hope, according to Unisanté. The vaccine has the potential to provide effective cellular immunity, long-term protection and better suited to viral mutations.
Unisanté was commissioned to carry out a phase 1 clinical study in Lausanne to determine whether the vaccine does not induce severe undesirable side effects in healthy volunteers. Twenty-six people have been recruited.
“In August, they all already received a first dose. Half have now received the second, ”said Genton. To assess the results, close follow-up is planned for six months.
Also against the Covid
Subject to regulatory approval, a Covid-19 vaccine using the same technology will be tested at Unisanté after this dengue study. This vaccine may prove to be more effective against new variants of the SARS-CoV-2 virus. The ethics commission of the canton of Vaud has already given its approval. It remains to obtain the green light from Swissmedic.
This vaccine is also developed by Emergex Vaccines. “It uses the same technology as the one for dengue fever. It could constitute an additional vaccine against Covid, especially if current vaccines prove to be less effective against new variants. ”
Blaise Genton hopes to start the phase 1 clinical study before the end of the year. For dengue as for Covid, new studies on a larger scale should follow: on 200 to 1,000 people in phase 2, then up to 10,000 volunteers in phase 3.
“We are still quite far from it,” recognizes Mr. Genton. It could take five years, even if things are moving faster now ”.