biostudies-literatureUnknown13Qiu GCOVID-19 vaccination is the most effective strategy for preventing severe disease and death. Inactivated vaccines are the most accessible type of COVID-19 vaccines in developing countries. Several studies, including work from our group, have demonstrated that the third dose (booster vaccination) of inactivated COVID-19 vaccine induces robust humoral and cellular immune responses. The present study aimed to examine miRNA expression profile in participants who received a homologous third dose of the CoronaVac vaccine. Samples of peripheral blood mononuclear cells (PBMCs) were collected from healthcare volunteers both before and 1-2 weeks after the booster dose. miRNA microarray analysis in a discovery cohort of six volunteers identified 67 miRNAs with differential expression. Subsequently, tPeerJe18856https://www.ebi.ac.uk/biostudies/studies/S-EPMC11760199biostudies-literatureAltered expression of miRNA profile in peripheral blood mononuclear cells following the third dose of inactivated COVID-19 vaccine.PMC11760199Qian HQiu GXia JShu QLe ZZang RZheng GZhang RHuang RWang JXu JfalseAltered expression of miRNA profile in peripheral blood mononuclear cells following the third dose of inactivated COVID-19 vaccine.COVID-19 vaccination is the most effective strategy for preventing severe disease and death. Inactivated vaccines are the most accessible type of COVID-19 vaccines in developing countries. Several studies, including work from our group, have demonstrated that the third dose (booster vaccination) of inactivated COVID-19 vaccine induces robust humoral and cellular immune responses. The present study aimed to examine miRNA expression profile in participants who received a homologous third dose of the CoronaVac vaccine. Samples of peripheral blood mononuclear cells (PBMCs) were collected from healthcare volunteers both before and 1-2 weeks after the booster dose. miRNA microarray analysis in a discovery cohort of six volunteers identified 67 miRNAs with differential expression. Subsequently, t2025-01-01T00:00:00Z20252026-06-01T18:06:19.46Z2025-04-04T22:07:48.013ZS-EPMC117601993986655710.7717/peerj.18856