Age

History of COVID-19 pneumonia

Antibody

titer

(U/mL)

Occupation

Medical services for patients with fever or COVID-19

History of contact with COVID-19 outside the hospital

50s

Yes

34.1

Administrative

staff

No

Yes

40s

Yes

72.0

Nurse

No

Yes

N.A.^a

N.A.^a

109.5

N.A.^a

N.A.^a

N.A.^a

N.A.^a

N.A.^a

127.0

N.A.^a

N.A.^a

N.A.^a