Despite unvaccinated people being most likely to become infected with COVID-19, there are still a number of reported breakthrough cases. Breakthrough cases are people who test positive for COVID-19 after they’ve already had the vaccine.
Age is thought to be a possible factor in those who experience breakthrough cases. Preexisting conditions may also play a role.
Data appears to show the a person who is severely immunocompromised may be as likely to have a breakthrough case as an 85-year-old. The strongest data is based on age though.
Data is also showing that people with preexisting conditions are getting COVID-19, and they’re getting it more than people who are unvaccinated catching COVID-19.
Experts seem to think that when it comes to breakthrough cases, it’s a specific vaccinated population that are coming down with COVID-19, not just random vaccinated people.
The number of breakthrough cases are so high in people with underlying health conditions because they’re vaccinated to begin with. Their chances of contracting the virus among that specific population are always higher than any other.