Here’s the short version for the night-shift crowd: a 2024 study of 1,103 manufacturing workers in Korea found that shift workers were more likely to “miss” a protective antibody response after the standard 3-dose hepatitis B vaccine—about 3 times the odds compared with day workers after researchers adjusted for age, sex, vitamin D, smoking, and starting antibody levels (adjusted OR 2.87; 95% CI 1.64–5.05). Non-response was also linked to being older, male, vitamin-D-deficien