Hong Kong and U.S. scientists have developed a new vaccine against the H5N1 bird flu virus that could be cheaper and more effective than its predecessors, according to scientists at the University of Hong Kong.

Microbiologists from the university and the National Institutes of Health in the U.S. said the vaccine, created by genetically modifying a smallpox vaccine, had a quicker immune response than existing alternatives. As such, it is a potential solution to future H5 pandemics, said the researchers.

“A single dose of the vaccine will provide rapid protective immune responses,” the university said in a statement. “In a H5 pandemic situation, such vaccines may have to be deployed at short notice. The induction of good and rapid protective immune response after the first dose of vaccine is a major advantage,” the university said.

The production of the vaccine does not require sophisticated facilities, making it easier for poor countries to produce, said the university. The team hopes the new vaccine can ride on the various advantages of the smallpox vaccine, which is very cheap and has a shelf life of several years, a report in the South China Morning Post said recently.