One-shot chikungunya vaccine found safe,
The first phase 3 trial of the vaccine, which was reported in The Lancet journal, indicated that it was safe and that it elicited a potent immune response against the viral illness.
However, because the study was not carried out in areas where chikungunya is widespread, the researchers were unable to determine whether the VLA1553, a vaccine created by French biotech company Valneva, offers protection against subsequent illness.
The chikungunya virus (CHIKV), which is widespread in several parts of Africa, Asia, and the Americas, is responsible for the mosquito-borne illness known as chikungunya.
Patients experience a fever four to eight days after being bitten by an infected mosquito. Headaches, exhaustion, nausea, and excruciating joint and muscular pain are among the symptoms.
The joint pain is typically excruciating and lasts a few days, but it can last longer, for weeks, months, or even years. Serious illness and death are uncommon, but older individuals and newborns are the groups most in danger.
There are now no effective antiviral treatments for the illness caused by CHIKV infection, nor are there any licensed immunizations to prevent the illness.
“This could be the first chikungunya vaccine available for people living in endemic regions, as well as for travelers to endemic areas or areas at risk for an upcoming outbreak,” said Martina Schneider, the study’s primary author and Clinical Strategy Manager at Valneva.
“Our encouraging results demonstrated good persistence of antibody levels following vaccination, which is crucial given the possibility of abrupt recurrence of chikungunya epidemics. The high immune response shown in older participants may be especially helpful because age is a risk factor for the severity and death of chikungunya disease, according to Schneider in a statement.
There is no specific treatment or vaccination for chikungunya, according to study author Katrin Dubischar, Programme Director, Chikungunya Vaccination at Valneva.
Furthermore, research has revealed that climate change is causing the mosquitoes that spread the virus to expand into new parts of the world. It is now thought to be one of the viruses that are most likely to spread globally. Therefore, having an effective vaccination is crucial for being ready for such outbreaks in the future, according to Dubischer.
The Global Research
In over 43 research locations in the US, 4,115 healthy participants were enrolled in the study. 3,082 subjects received one injection of VLA1553 in the arm, while 1,033 received a placebo.
Although the immunological response was only examined in a subgroup of 362 participants (266 of whom received the vaccination and 96 a placebo), all participants were included in the safety analysis.
Following immunization, the immunological responses of the participants were evaluated one week, 28 days, three months, and six months later. For 11 days following immunization, they also kept an electronic diary of side effects.
99 percent (263/266) of subjects had antibody levels that were deemed protective against illness following a single dose of VLA1553. There was no distinction between immune.
Across all age groups, VLA1553 was generally well tolerated, with the majority of side effects being mild or moderate. Headaches, weariness, muscle pains, joint discomfort, and pain at the injection site were the most frequent adverse reactions in those who received the vaccine. After six months, those who received VLA1553 had more adverse events reported than those who received a placebo. The safety profile for older adults was the same as for adults.
The study’s weaknesses are noted by the authors. Participants’ pre-existing immunity to the chikungunya virus and the safety of the vaccination in this population is unknown because the study did not take place in an area where the virus is endemic.
According to Kathryn Stephenson of the Beth Israel Deaconess Medical Center’s Centre for Virology and Vaccine Research, “the positive results of this trial are very good news for CHIKV pandemic preparedness.”
Stephenson, who was not involved in the study, stated that “CHIKV and other arboviral infections continue to be global threats, spurred on by the expansion of mosquito habitats due to climate change and the globalization of trade and travel.”
According to Stephenson, “real-world effectiveness studies in the setting of actual CHIKV outbreaks, as well as further investigations of VLA1553 in endemic regions and enlarged populations, such as a current study in teenagers in Brazil, will be crucial to establishing VLA1553’s utility for CHIKV prevention.
