This paper presents a novel coronavirus herd immunity optimization (CHIO) algorithm for tuning the proportional-integral-derivative (PID) controller for the DC-DC boost converter. The closed-loop control action using the PID controller is designed to regulate the output voltage of DC-DC boost converter across the load end. CHIO is a nature-inspired meta-heuristic optimization algorithm formulated based on the way humankind handled the coronavirus pandemic (COVID-19) in recent years. This optimization algorithm exploits the herd immunity and social distancing concepts. The optimization algorithm has been developed on MATLAB/Simulink software for obtaining the optimum PID controller gains. Extensive simulations are conducted under (i) start-up response, (ii) reference voltage change (iii) load resistance change, and (iv) input voltage change to find the performance of the proposed controller. The obtained results indicate a successful convergence and satisfactory dynamic response of the output voltage under wide variation in the operating points.