Please choose the correct ending to complete the given sentence: Health: [header] How to protect yourself from seasonal flu [title] Get the influenza vaccine. [step] Each year, the cdc, world health organization and other public-health groups study the newest strains of influenza and quickly develop effective vaccines to protect people. Cdc officials consider the flu shot to be the most effective barrier against becoming infected.

Ending1: [title] Become repellent to widespread cold and flu. [step] People experiencing seasonal flu flu in very cold places can derive flu benefits with the flu. Ending2: Groups like : [substeps] The cgs (cdc dept. , fmcb) and telarna (cdc, fmcb). Ending3: [substeps] The cdc also suggests giving vaccines for treating seasonal flu. Check the dhs's vaccine card to make sure the vaccine is active. Ending4: The vaccine contains inactive viruses from the 3 strains researchers believe will be most prevalent during the flu season. The cdc encourages everyone to get immunized, particularly people in high-risk groups.

Answer format: ending1/ending2/ending3/ending4