Conclusions
In this RCT, SOC-tailored online intervention was more effective than the non–SOC-tailored intervention in increasing the SIV uptake among Hong Kong residents 65 years or older. Interventions tailored to SOC might facilitate participants to progress to a higher SOC. Adults 65 years or older also had higher compliance to the SOC-tailored intervention. These findings suggest that SOC-tailored interventions may be a sustainable new method for increasing SIV uptake for this population.