The Centers for Disease Control and Prevention identified about 5,800 cases of people who were fully vaccinated against the coronavirus-borne disease COVID-19, but became infected, CNN reported. Some became seriously ill and 74 people died, the CDC told CNN by email. “To date, no unexpected patterns have been identified in the demographics or vaccine characteristics,” the CDC said. It is not unexpected to have these “breakthrough” cases, as the vaccines are not 100% effective in preventing infections, making it important that people continue to wear face masks and social distance even after they have been vaccinated. The agency said it will look for clues as to who is most likely to become infected, despite having been vaccinated. “Breakthrough vaccine infections were reported in all people of all ages who were eligible for vaccination. However, just over 40% of infections occurred in people 60 years of age or older,” the CDC said.