Precise and rapid disease detection is critical for controlling infectious diseases like COVID-19. Current technologies struggle to simultaneously identify viral RNAs and host immune antibodies due to limited integration of sample preparation and detection. Here, we present acoustofluidic integrated molecular diagnostics (AIMDx) on a chip, a platform enabling high-speed, sensitive detection of viral immunoglobulins [immunoglobulin A (IgA), IgG, and IgM] and nucleic acids. AIMDx uses acoustic vortexes and Gor'kov potential wells at a 1/10,000 subwavelength scale for concurrent isolation of viruses and antibodies while excluding cells, bacteria, and large (>200 nanometers) vesicles from saliva samples. The chip facilitates on-chip viral RNA enrichment, lysis in 2 minutes, and detection via transcription loop-mediated isothermal amplification, alongside electrochemical sensing of antibodies, including mucin-masked IgA. AIMDx achieved nearly 100% recovery of viruses and antibodies, a 32-fold RNA detection improvement, and an immunity marker sensitivity of 15.6 picograms per milliliter. This breakthrough provides a transformative tool for multiplex diagnostics, enhancing early infectious disease detection.