By KIM TONG-HYUNG
SEOUL, South Korea (AP) — South Korea is enforcing new COVID-19 response measures, including reduced quarantine periods and expanded rapid testing as its new cases jumped nearly 50% in a day. It underscores the speed of transmissions driven by the highly contagious omicron variant, which became the country’s dominant strain just last week. More than half of the population got their booster shots. Still, there are concerns that a sudden explosion in infections could disrupt health care and send huge numbers into quarantine. Starting Wednesday, the quarantine period for those who test positive after being fully vaccinated was reduced from 10 to seven days. Fully vaccinated people who come in close contact with those infected will no longer be quarantined. Most people will first use rapid instead of PCR tests.