ANDREA SHALAL  THE U.S. government will ship nearly 10 million doses of COVID-19 vaccines to two of the most populous African countries - Nigeria and South Africa - as the continent battles a third wave of infections, White House officials said. Four million doses of the Moderna COVID-19 vaccine will go to Nigeria and 5.66 million doses of the Pfizer vaccine to South Africa, the officials said. The South Africa shipment is the single largest sent by the United States since it began sending vaccine shots overseas, one of the officials said. The latest shipments bring the total number of…