An experimental vaccine designed to protect against many flu virus strains has yielded promising results in an efficacy trial. NIAID investigator Matthew J. Memoli, M.D., designed and led the trial, which involved administering one or two doses of the experimental vaccine or a placebo injection to healthy adults. All the volunteers were later exposed to a strain of seasonal influenza virus under carefully controlled conditions. The aim was to determine whether the experimental vaccine, FLU-v, lessened the chance that a volunteer would develop flu symptoms and viral shedding. Trial results were published March 13 in the journal npj Vaccines.

H1N1 influenza virus particles/National Institute of Allergy and Infectious Diseases (NIAID)

FLU-v is an example of a “universal” influenza vaccine candidate, a still-experimental vaccine that may provide long-lasting protection against most or all flu strains. Traditional seasonal flu vaccines trigger production of antibodies aimed at a part of a flu virus surface protein that varies widely from strain to strain and that changes continuously. Therefore, flu vaccines must be re-formulated and administered annually to match newly arising strains. In contrast, FLU-v is designed to prompt a response not by antibodies, but by a separate arm of the immune system—cellular immunity. Cellular immune responses include activity by white blood cells called cytotoxic T lymphocytes (CTLs). Recent research has shown that influenza-specific CTLs can seek out and remove virus-infected cells before and after flu symptoms arise. The FLU-v vaccine is designed to stimulate production of these flu-specific CTLs by targeting several proteins inside the virus that do not vary much from strain to strain, meaning that CTL responses against them may be effective against many virus strains. FLU-v is being developed by the London-based company PepTcell (SEEK).

Read more at NIAID


Got Smallpox?