Association between vaccination status and clinical characteristics among young adults infected with COVID-19

To explore the association between Vaccination Status and Clinical Characteristics Among Young Adults Infected With COVID-19.

We conducted a cross-sectional Survey among young adults aged 16-35 years in Tianjin, China. Our analysis focused on COVID-19 infection rates, risk factors, demographic characteristics, and clinical symptoms.

We collected 738 valid questionnaires between December 20 to 23, 2022, achieving a response rate of 98.27%. Among the 412 infected participants, 33.25% were male and 66.75% were female, with a marginal significant difference (P = 0.054). The distribution of infected participants across various age groups, as well as the presence or absence of co-residents, showed a significant difference between the infected and uninfected cohorts (P = 0.003 and P < 0.001, respectively). Compared with participants who received two or less vaccine dose, participants who had received three or more doses of vaccine had a significantly lower incidence of headache (0-2 vs. > = 3 doses: 80.43% and 69.38%, P = 0.038), olfactory reduction or loss (0-2 vs. > = 3 doses: 22.83% and 14.06%, P = 0.043). Compared with the time since vaccination of 7-12 months, those vaccinated with less than 6 months or more than 12 months exhibited a higher incidence of fatigue (< 6 vs. 7-12 vs. > 12 months: 75.41%, 63.13% and 77.61%, P = 0.009) but a lower incidence of vomiting (< 6 vs. 7-12 vs. > 12 months: 8.20%, 17.51% and 8.21%, P = 0.020).

Our study found that young adults who received three or more doses of the COVID-19 vaccine had a lower incidence of symptoms such as headache and olfactory reduction. These findings underscore the importance of vaccination in mitigating the severity of COVID-19 symptoms and provide valuable insights for future public health strategies and vaccine policies.