The communication plan for our HPTN 083 implementation is not ready yet, but I would advocate for online tools to be defined there as its main resource, as it is fast, cheap, easy to update and, most important, centralized. For instance, an official website for the trial will deliver consistent and updated information across all visitors, which is great to avoid inaccuracies and hearsays.
On the other hand, false information can spread very quickly in social media, so no communication/issue management plan for a successful trial can afford to overlook that anymore.