I was looking at VFS application and there it said that you need yellow fever vaccination ONLY if you are visiting South Africa for more than 3 months. Fortunately, for me as I'm on a conference mailing list came to know it is advisable to at least take 'Hep A' vaccination 2 weeks before travel. I did look at http://www.vfsglobal.com/southafrica/india/conferences.html and various vfsglobal pages which mention nothing as well as all the useful links which also mention everything else except medical advice. I did see the UK one question and that is a long list and scary . Health vaccinations for UK
It would be nice if such information could be known somewhere. The UK guys on my conference list got some medical advisory hence I came to know that it is needed so did so.