Wayne Marasco is no doubt the only Harvard medical researcher who abandoned a successful construction firm, Waymar Roofing and Siding, to become an immunologist. The man with the unorthodox history recently made a striking discovery: a human antibody that attacks a newfound vulnerability in flu viruses. His finding could be the key to a single, perennial vaccine against all forms of influenza, including swine flu.
Vaccines work by training the body's immune system to recognize distinctive molecules on the surface of a virus. The body then makes antibodies that grab those molecules and disable the virus. But flu viruses constantly change the shape of their surface molecules. So the vaccine that 143 million Americans get annually has to be matched each year to the mutating virus. That process takes months, making it hard to quickly cook up a vaccine for a new bug.
Enter Marasco, a specialist in immunochemistry and infectious diseases at the Dana-Farber Cancer Institute and Harvard Medical School. Marasco, 56, was the first person in his family to go to college, where a job as a kidney dialysis technician got him interested in the immune system. After his detour through the roofing trade, Marasco graduated and got his Ph.D. and M.D.
His discovery started a decade ago, when he worked with a postdoc and a technician to create a library of 27 billion antibodies from the blood of 57 human volunteers. With that library, his lab could quickly find an antibody for the SARS virus in 2004, using a molecular technique he calls "panning," after the old gold prospecting method. Panning involves mixing the antibodies with a target virus. "Then you wash away everything that doesn't bind to the virus," he says. Any antibody that remains is a precious find.
After SARS, Marasco started searching for antibodies to the H5N1 bird flu virus. By 2007, he had found an antibody that stuck to all four circulating bird flu strains, the 1918 pandemic flu, and representatives of 8,000 other flu strains. Tests revealed a paradigm-shifting fact: The antibody disables these diverse strains because it latches onto the stem of a lollipop-shaped part of the virus that rarely mutates. It then gums up the machinery the virus needs to invade human cells.
"He used a very clever, elegant molecular technique to identify something we normally never would have noticed," says Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases.
Quite a few companies have inquired about creating a vaccine from the newly identified antibody, but "exciting as it is, it's going to be years before it's actually applicable," says Fauci. Swine flu might accelerate that process; testing is underway to see if the antibody will work against this year's pandemic strain, too.