The Lassa virus may not get as much media coverage as its better-known cousin Ebola, but it causes similar symptoms and kills thousands in Africa every year.
And now, San Diego researchers say they have taken an important step toward developing a vaccine for the deadly virus.
After a 10-year effort, researchers led by scientists at the Scripps Research Institute have finally unlocked the structure of a key protein the Lassa virus uses to infect human cells.
"It works like a spearfishing rod," said Scripps professor Erica Ollmann Saphire. "It wants to project a hook forward and unfold and collapse itself into the human cells. The best antibodies from human survivors work by locking that machinery in place."
To obtain antibodies from Lassa survivors, the researchers worked with a clinic in Sierra Leone staffed entirely by people who recovered from the Lassa infection and became immune.
Led by Ollmann Saphire and Scripps staff scientist Kathryn Hastie, the researchers were able to see how survivors' antibodies bind to the protein, disabling the virus. They say this discovery should speed up development of a Lassa vaccine.
"Scientifically, we're very close," said Ollmann Saphire. "The molecule we have is ready to go immediately. The next step is to put it on the surface of a vaccine and prove it generates the responses we think it will."
The researchers' discovery is outlined in a study published Thursday in the journal Science.
Ollmann Saphire's lab has also worked extensively on Ebola. Their research led to the development of ZMapp, a drug given to a number of patients during the Ebola outbreak that began in 2014.