The very first nCoV genome sequencied earlier this month[0] ends with 33 As, while the genome of the virus found in the first U.S. patient[1] ends with only 12

The very first nCoV genome sequencied earlier this month[0] ends with 33 As, while the genome of the virus found in the first U.S. patient[1] ends with only 12 As. Is it normal for there to be variation here? Do these repeated A sequences actually code for a protein or are they just a marker to let the ribosome know it's reached the end of the genome, and so the length of repeating As doesn't really matter past a certain point? (I'm obviously not a biologist) [0]https://www.ncbi.nlm.nih.gov/nuccore/MN908947 https://www.ncbi.nlm.nih.gov/nuccore/MN908947 [1]https://www.ncbi.nlm.nih.gov/nuccore/MN985325 https://www.ncbi.nlm.nih.gov/nuccore/MN985325