WHO SAGE 2022 defined “high-risk” groups for developing severe disease resulting in hospitalization or death (such as older adults, pregnant women and women up to 2 weeks postpartum, children, people with a BMI or 40 or higher, and people with comorbidities) and those at increased risk of exposure to or transmission of influenza virus (such as health workers).
See position paper
Several potentially universal, broadly protective, or next-generation influenza vaccine candidates are in phase 2 trials.