News

Chikungunya vaccine safe, immunogenic in phase I trial

View on the News

Burden of outbreaks should encourage development

"Although this VLP vaccine candidate exhibits a range of properties that suggest it would be a good vaccine option, there is always concern about whether a vaccine for a vector-borne virus will be licensed," said Dr. Ann M. Powers. "Development of vaccines for orphan agents is challenging, because the market might not be large enough to justify the investment."

Developing a vaccine in the United States costs an estimated $200-$500 million; nonetheless, vaccines are the most cost-effective way to prevent disease, she said. "In view of the burden of chikungunya outbreaks, which have affected up to 63% of local populations in a matter of months, the continued development of this VLP vaccine candidate, along with other vaccine options, should be encouraged."

A VLP contains the outer structural proteins of the virus that the immune system typically recognizes, Dr. Powers added. But it does not contain live genetic material, which confers a safety and manufacturing advantage because high-containment facilities are not needed for production.

Dr. Powers is with the division of vector-borne diseases at the U.S. Centers for Disease Control and Prevention. She declared that she had no competing interests. These remarks were excerpted from her editorial accompanying Dr. Chang’s report (Lancet 2014 Aug. 15 [doi: 10.1016/S0140-6736(14)61290-3]).


 

FROM THE LANCET

References

A novel chikungunya virus vaccine caused no serious adverse effects and was about as immunogenic as natural infection, authors of a phase I trial reported in the Lancet.

Eleven months after receiving the noninfectious viruslike particle (VLP) vaccine, trial participants had neutralizing antibody titers that resembled those seen in natural infection, said Dr. Lee-Jah Chang and associates at the National Institutes of Health in Bethesda, Md. (Lancet 2014 Aug. 15 [doi: 10.1016/S0140-6736(14)61185-5]).

Chikungunya virus infection is rarely fatal, but it causes fever and severe arthritis. The mosquito-born pathogen spread to the Americas in 2013, is now epidemic in the Caribbean, and has no approved vaccine or treatment.

To test a novel VLP vaccine candidate, researchers enrolled 25 healthy adults into a phase I, open-label, dose-escalation trial with doses of 10, 20, or 40 mcg administered at weeks 0, 4, and 20, the investigators reported. Participants were followed for 44 weeks after enrollment.

All groups had detectable neutralizing antibodies on ELISA (enzyme-linked immunosorbent assay) after the second dose, with geometric mean titers of the half-maximum inhibitory concentration of 2,688 in the 10-mcg group, 1,775 in the 20-mcg group, and 7,246 in the 40-mcg group. Antibody levels after the second dose substantially exceeded those measured after the first dose, with P values for differences ranging from .07 for the 10-mcg group to less than .0001 for the 40-mcg group, the investigators said. And titers did not significantly differ 4 weeks after the second and third doses, they added.

Participants reported no arthralgias or other serious adverse effects. Mild to moderate side effects occurred in four participants, and consisted of transient neutropenia (three cases) and transient increases in alanine aminotransferase (four cases), all of which resolved without clinical consequences, the investigators said.

"These clinical data represent an important step in vaccine development to combat this rapidly emerging pathogen," the researchers said. The next step is to test the vaccine in larger studies that include persons at risk of chikungunya virus infection, they added.

The trial was funded by the Intramural Research Program of the Vaccine Research Center, National Institute of Allergy and Infectious Diseases; and the National Institutes of Health. The authors declared no competing interests.

Recommended Reading

New agent shortened HSV-2 shedding
MDedge Rheumatology
CDC sounds alarm on hospital antibiotic use
MDedge Rheumatology
Switching biologic may lower risk of second infection-related hospitalization in RA
MDedge Rheumatology
CDC: Heartland virus cases could resume in May
MDedge Rheumatology
Plasma fluoride levels tied to voriconazole-induced periostitis
MDedge Rheumatology
SSTI guidelines stress diagnostic skill, careful treatment
MDedge Rheumatology
First locally acquired cases of chikungunya reported in Florida
MDedge Rheumatology
VIDEO: Dr. Fauci: What you need to know about chikungunya
MDedge Rheumatology
Spiroindolone ‘KAE609’ rapidly cleared falciparum, vivax malaria
MDedge Rheumatology
Settling a malpractice suit is seldom a straightforward decision
MDedge Rheumatology