Serum Fibronectin Levels Increased Significantly Following the Administration of an Inactivated SARS-CoV-2 Vaccine: A Prospective Observational Study.

Background: There has been a lack of comprehensive studies on the long-term observation of laboratory values following the administration of SARS-CoV-2 vaccines. The objective of this study is to assess the long-term impact of inactivated SARS-CoV-2 vaccines on coagulation function and other health indicators. Methods: We enrolled residents of Chengdu who consented to receive inactivated SARS-CoV-2 vaccines, categorizing them into two groups: healthy donors (n=40) and survivors of COVID-19 infection (n=34), based on their SARS-CoV-2 infection status prior to vaccination. Blood samples from the subjects were collected at specific intervals following vaccination. Results: The levels of Fibronectin (FN) increased significantly in both healthy donors and survivors of COVID-19 infection after receiving two doses of the inactivated SARS-CoV-2 vaccine (both P < 0.001), and there was no statistically significant difference in the degree of FN increase between the two groups (153.05 ± 77.19 mg/L vs 172.32±90.42 mg/L, P=0.326). The rate of elevated FN levels was significantly higher six months after vaccination compared to the rate before vaccination, both in healthy donors (85.0% vs 5.0%, P<0.001) and in survivors of COVID-19 infection (94.1% vs 29.4%, P<0.001). Additionally, the levels of FN in healthy donors further increased six months after receiving a booster dose of the inactivated vaccine compared to pre-booster levels (569.90±119.44 mg/L vs 467.35±62.04 mg/L, P < 0.001). Conclusion: The study indicates that serum FN levels increased significantly following the administration of the inactivated SARS-CoV-2 vaccine, and these elevated FN levels may persist for more than six months. However, it remains unclear whether this increase could result in any adverse effects.