Breakthrough cases were rare at that point.

Our worst nightmare came true."

Breakthrough cases occur when a fully vaccinated person gets severely ill or dies from Covid-19.

Deaths among the fully vaccinated are rare, according to the US Centers for Disease Prevention and Control.

Between early April and mid-July -- during some of which time the Delta variant was the dominant strain -- fully vaccinated people represented 8% of all Covid-19 cases, 8% of hospitalizations and 9% of deaths, according to a CDC study published earlier this month.

About 70% of breakthrough cases resulting in hospitalization were among adults 65 and older and about 87% of breakthrough cases resulting in death were among adults 65 and older, according to the CDC data.

Ayers described that the family is having a tough time processing what has happened and wanting to find a way to inspire others to get a vaccine and wear a mask.

Because of our story," Ayers said, "people have told us they are getting vaccinated.