TY - JOUR
T1 - Serological surveillance of healthcare workers to evaluate natural infection- and vaccine-derived immunity to SARS-CoV-2 during an outbreak in Dili, Timor-Leste
AU - Arkell, Paul
AU - Gusmao, Celia
AU - Sheridan, Sarah L.
AU - Tanesi, Maria Y.
AU - Gomes, Nelia
AU - Oakley, Tessa
AU - Wapling, Johanna
AU - Alves, Lucsendar
AU - Kopf, Stacey
AU - Sarmento, Nevio
AU - Barreto, Ismael Da Costa
AU - Amaral, Salvador
AU - Draper, Anthony DK
AU - Coelho, Danina
AU - Guterres, Helio
AU - Salles, Antonio
AU - Machado, Filipe
AU - Fancourt, Nicholas SS
AU - Yan, Jennifer
AU - Marr, Ian
AU - Macartney, Kristine
AU - Francis, Joshua R.
N1 - Funding Information:
This work was supported by the Department for Foreign Affairs and Trade of the Australian Government (Complex Grant Agreement Number 75889).
PY - 2022/6
Y1 - 2022/6
N2 - Background Serosurveillance can be used to investigate the extent and distribution of immunity to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) within a population. Characterisation of humoral immune responses gives insight into whether immunity is infection- or vaccine-derived. Methods A longitudinal study of health care workers (HCWs) in Dili, Timor-Leste, was conducted during vaccine rollout (ChAdOx1) and a concurrent SARS-CoV-2 outbreak. Results A total of 324 HCWs were included at baseline (April-May 2021). Out of those, 32 (9.9%) were seropositive for anti-nucleocapsid protein (anti-N) IgG antibodies, indicating a significant sub-clinical infection among HCWs early in the local outbreak. Follow-up was conducted in 157 (48.5%) participants (July-September 2021), by which time there had been high uptake of vaccination (91.7%), and 86.0% were seropositive for anti-spike protein antibodies. Acquisition of anti-N antibodies was observed in partially vaccinated HCWs (30/76, 39.5%), indicating some post-dose-1 infections. Discussion Serosurveillance of HCWs may provide early warning of SARS-CoV-2 outbreaks and should be considered in non-endemic settings, particularly where there is limited availability/uptake of testing for acute infection. Characterisation of humoral immune responses may be used to assess vaccine impact and coverage. Such studies should be considered in national and international efforts to investigate and mitigate against future emerging pathogens.
AB - Background Serosurveillance can be used to investigate the extent and distribution of immunity to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) within a population. Characterisation of humoral immune responses gives insight into whether immunity is infection- or vaccine-derived. Methods A longitudinal study of health care workers (HCWs) in Dili, Timor-Leste, was conducted during vaccine rollout (ChAdOx1) and a concurrent SARS-CoV-2 outbreak. Results A total of 324 HCWs were included at baseline (April-May 2021). Out of those, 32 (9.9%) were seropositive for anti-nucleocapsid protein (anti-N) IgG antibodies, indicating a significant sub-clinical infection among HCWs early in the local outbreak. Follow-up was conducted in 157 (48.5%) participants (July-September 2021), by which time there had been high uptake of vaccination (91.7%), and 86.0% were seropositive for anti-spike protein antibodies. Acquisition of anti-N antibodies was observed in partially vaccinated HCWs (30/76, 39.5%), indicating some post-dose-1 infections. Discussion Serosurveillance of HCWs may provide early warning of SARS-CoV-2 outbreaks and should be considered in non-endemic settings, particularly where there is limited availability/uptake of testing for acute infection. Characterisation of humoral immune responses may be used to assess vaccine impact and coverage. Such studies should be considered in national and international efforts to investigate and mitigate against future emerging pathogens.
KW - ChAdOx1
KW - COVID-19
KW - healthcare worker
KW - SARS-CoV-2
KW - serological surveillance
KW - vaccination
UR - http://www.scopus.com/inward/record.url?scp=85128206420&partnerID=8YFLogxK
U2 - 10.1016/j.ijid.2022.03.043
DO - 10.1016/j.ijid.2022.03.043
M3 - Article
C2 - 35358723
AN - SCOPUS:85128206420
SN - 1201-9712
VL - 119
SP - 80
EP - 86
JO - International Journal of Infectious Diseases
JF - International Journal of Infectious Diseases
ER -
