How did the Black Death likely spread so rapidly in medieval Europe, according to the video?

Direct person-to-person contact

According to the video, what were some of the factors that made Europeans particularly vulnerable to the Black Death in the 14th century?

Famine, poverty, and poor health

I can analyze the impact of the bubonic plague on European society.

1
The Black Death, caused by the bacterium Yersinia pestis, killed nearly 50% of Europeans in just four years during the 14th century.
2
Genetic comparisons of ancient to modern strains of Yersinia pestis suggest that the key to the Black Death's high mortality rate lies not in the parasite, but in the host's vulnerability due to factors like malnutrition and poor health.
3
The Black Death led to higher living standards, increased social mobility, and a population with a different gene pool, including genes that may have helped survivors resist the disease.