When will the Black Death level pandemic occur?

The time between the plague of Athens (431 BCE) and the Antonine Plague (165 CE) was 595 years. <br><br>The time between the Black Death and the Spanish Flu was 581 years. <br><br>The Spanish Flu happened in 1918. If it follows the same time frame, we should expect another massive pandemic around 2500 CE. <br><br>When will the next Black Death level pandemic occur?