Recent study revealed a new way which could help in to fulfilling storage of vaccine. Researchers found that half-dose flu shots are as effective as a full dose in people under age 50 who have been previously vaccinated.

Research team led by Dr. Renata Engler of the Walter Reed Army Medical Center in Washington, D.C. conducted a clinical trial involving healthy adults aged 18 to 64.

The study of more than 1,000 subjects revealed that those who received the half-dose vaccine produced a similar immune response to the flu compared to those who received the full-dose vaccine.

Study also revealed that rates of doctor visits for respiratory and cardiovascular problems were similar among those who received the full- and half-dose vaccine. Researchers found that women receiving a half-dose of the vaccine had similar antibody responses to men receiving a full dose

The researchers said that antibody responses in healthy, previously immunized adults "were not substantially inferior to the full-dose vaccine, particularly for ages 18 to 49 years."

Researchers said: "Reduced dosing could have a significant impact on the response to vaccine shortages, particularly at a local level when faced with considerable delays in vaccine supply delivery".