In the midst of an unprecedented crisis, Democrat Joe Biden assumes the presidency of the United States today; the case of Salvador Cienfuegos strained the US-Mexico diplomatic relationship, while yesterday the public prosecutor, Alejandro Gertz Manero, defended in an interview the non-exercise of criminal action against the general and said he was willing to litigate in international instances; the vaccine delivery schedule has been postponed to February, but authorities say it does not affect the announced plan.