What makes the Delta Variant of COVID-19 so different? By FOX 7 Austin Digital Team Published What makes the Delta Variant of COVID-19 so different? Infectious disease specialist Dr. Parker Hudson with Dell Medical School explains how this mutation is different from the original virus, and what we can do to stop the spread. AUSTIN, Texas - After declining for months, COVID-19 cases are spiking again in Austin and around the country, thanks in part to the highly contagious Delta variant. Infectious disease specialist Dr. Parker Hudson explains how this mutation is different from the original virus, and what the public can do to stop the spread.