South Korea has confirmed five other cases of what's called a breakthrough COVID-19 infection where a fully vaccinated person tests positive for the virus.

The Korea Disease Control and Prevention Agency(KCDA) on Thursday registered a total of nine domestic cases of breakthrough infections as of 12 a.m. Monday. The total has risen by five from the previous tally compiled on May 21. 

That’s about point-0004 percent of some two-point-14 million people who’ve been fully vaccinated in the country. 

The agency defines breakthrough cases as patients who become infected with COVID-19 even after receiving the two full doses of a vaccine in line with recommended standards. 

All local breakthrough cases involve Pfizer vaccine. The KDCA, however, cautioned against overgeneralization, saying three quarters of those fully vaccinated received Pfizer vaccine and such breakthrough infections can appear in cases involving other vaccine products as well.