(NEXSTAR) — 5,800 Americans have contracted COVID-19 after receiving the vaccine, a small percentage of the more than 75 million people who’ve been fully vaccinated.

Seventy-four fully vaccinated people have died (1% of those infected) and 7% were hospitalized.  

“COVID-19 vaccines are effective and are a critical tool to bring the pandemic under control,” the CDC said in a statement to Nexstar. “All of the available vaccines have been proven effective at preventing severe illness, hospitalizations, and deaths.  However, like is seen with other vaccines, we expect thousands of vaccine breakthrough cases will occur even though the vaccine is working as expected.”

Both the Pfizer and Moderna vaccines are 95% effective at preventing severe COVID-19 infection, the manufacturers have said.

The CDC said to date, “No unexpected patterns have been identified in case demographics or vaccine characteristics.”

Forty percent of infections occurred in those over 60 years of age, while 65% were female.

About 29% of the vaccine breakthrough infections were reportedly asymptomatic.

The CDC said it is monitoring reported cases “for clustering by patient demographics, geographic location, time since vaccination, vaccine type or lot number, and SARS-CoV-2 lineage.”

Where available, respiratory specimens that tested positive for COVID will be collected for genomic sequencing “to identify the virus lineage that caused the infection.”

The CDC created a national COVID-19 vaccine breakthrough database, where state health departments can enter, store and manage data for cases in their region.