CLEAN : South Africa starts coronavirus trial of TB vaccine

The video discusses a study that has begun enrolling participants, with plans to enroll 500 more over the coming weeks to months. The study is based on a similar one conducted in the Netherlands, focusing on outcomes related to the BCG vaccine and COVID-19 in the elderly. The follow-up schedule is flexible, with more frequent check-ins if the pandemic worsens in South Africa. The study aims to provide early results through regular analysis, with a final result expected next year.

What is the name of the study being done in the Netherlands that is similar to the one mentioned?

What factors might lead to more frequent follow-up calls to participants?