A single dose of the live-attenuated vaccine candidate VLA1553 for the prevention of disease caused by chikungunya virus produced a strong immune response, a phase III randomized trial showed.
At 28 days post-vaccine, 98.9% of participants in the per-protocol population who received the vaccine had seroprotective chikungunya virus neutralizing antibody levels (95% CI 96.7-99.8, P<0.0001), independent of age, reported Martina Schneider, PhD, the clinical strategy manager at Valneva in Vienna, the company that produces the vaccine, and colleagues.
Adverse events were similar to other licensed vaccines, and VLA1553 was well tolerated by both younger and older adults, they noted in The Lancet
“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,” Schneider said in a press release. “Our promising results showed good persistence of antibody levels after vaccination, which is important considering that chikungunya outbreaks may recur suddenly.”
No significant difference was seen in the seroprotection rate between patients ages 18 to 64 (98.6%) and those 65 and older (100%). At 180 days, 96.3% of those in the VLA1553 arm still had titers above the seroprotective level of antibodies.
“As age is a risk factor for severity and mortality of chikungunya disease, the strong immune response observed in older participants might be particularly beneficial,” Schneider said.