By Wendell Roelf CAPE TOWN (Reuters) -South Africa’s Afrigen Biologics has used the publicly available sequence of Moderna Inc’s mRNA COVID-19 vaccine to make its own version of the shot, which could be tested in humans before the end of this year, Afrigen’s top executive said on Thursday. The vaccine candidate would be the first to be made based on a widely used vaccine without the assistance and approval of the developer. It is also the first mRNA vaccine designed, developed and produced at lab scale on the African continent. The World Health Organization (WHO) last year picked a consortium …