Amid a resurgence of COVID-19, the fourth vaccine shot will be available to more people from Monday, including those aged 50 and older and people aged 18 and older who have underlying health conditions.

According to quarantine authorities, patients and workers at facilities vulnerable to the virus, such as nursing homes and homeless shelters, are also eligible for the second booster shot from Monday.

Previously, only people aged 60 and older and people with weakened immune systems were eligible for the fourth COVID-19 vaccine shot.

With the government broadening eligibility for a fourth dose of COVID-19 vaccines, people who were born between 1963 and 1972 can now receive the fourth dose at least 120 days, or four months, after their third shot.

Underlying diseases that qualify for the fourth shot, such as heart diseases and chronic lung diseases among others, are specified on the vaccine reservation website (ncvr.kdca.go.kr).

The applicants may make reservations on the vaccine reservation website or call the 1339 hotline to sign up.

The so-called mRNA vaccines, such as Pfizer or Moderna, are recommended for the fourth shot, but people may choose the Novavax vaccine if they want.