MONDAY, JUNE 18, 2018

Key to fighting malaria found in yellow fever vaccine

Researchers at Rockefeller University may have found a way to fend off malaria by using a yellow fever vaccine, according to a report.

Researchers were able to genetically alter the yellow fever vaccine to prime the immune system, which fends off the mosquito borne parasites that cause malaria. It was discovered that the modified yellow fever vaccine, along with a booster, gave mice immunity to malaria.

In the 1960s, scientists discovered that one form of the malaria parasite, the sporozoite, can wake up the immune system and help to protect against future infection. The only way to gather sporozoites, however, is to pluck them one-by-one from the salivary glands of irradiated, malaria-ridden mosquitoes. To provide immunity, the attenuated parasites must then be injected in high doses — or delivered by the bites of hundreds of mosquitoes — a labor intensive approach not feasible for large-scale use.

Charles M. Rice, head of the Laboratory of Virology and Infectious Disease at Rockefeller University, said he knew there had to be another way to get the benefits of sporozoite immunization. With that in mind, Rice and his team began looking at a yellow fever strain used in the yellow fever vaccine, known as YF17D, which has been used to successfully vaccinate more than 400 million people since 1937.

Researchers inserted the sequence of a malaria gene into the YF17D vaccine and found that the gene could produce its protein in cultured cells. The protein they chose, called CSP, covers the surface of the malaria sporozoite and is thought to be the main reason that this form of the parasite stimulates the immune system so effectively, Rice said.

“These results are exciting because they show the YF17D-CSP vaccine can prime the immune response against a malaria parasite,”lead author Cristina Stoyanov told “Although the utility of this approach for human immunization is not yet clear, the team hopes that further studies in other animal models might eventually lead to an effective vaccine.”