The potential of targeted antibody prophylaxis in SARS outbreak control: a mathematic analysis.
BACKGROUND
Severe acute respiratory syndrome (SARS) coronavirus-like viruses continue to circulate in animal reservoirs. If new mutants of SARS coronavirus do initiate another epidemic, administration of prophylactic antibodies to risk groups may supplement the stringent isolation procedures that contained the first SARS outbreak.


METHODS
We developed a mathematical model to investigate the effects of hospital admission and targeted antibody prophylaxis on the reproduction number R, defined as the number of secondary cases generated by an index case, during different SARS outbreak scenarios.


RESULTS
Assuming a basic reproduction number R(0)=3, admission of patients to hospital within 4.3 days of symptom onset is necessary to achieve outbreak control without the need to further reduce community-based transmission. Control may be enhanced by providing pre-exposure prophylaxis to contacts of hospitalized patients, and through contact tracing and provision of post-exposure prophylaxis. Antibody prophylaxis may also be employed to reduce R below one and thereby restrict outbreak size and duration.


CONCLUSIONS
Patient isolation alone can be sufficient to control SARS outbreaks provided that the time from onset to admission is short. Antibody prophylaxis as supplemental measure generally allows for containment of higher R(0) values and restricts both the size and duration of an outbreak.
Bogaards
Johannes Antonie
JA
Crucell Holland BV, PO Box 2048, 2301 CA Leiden, The Netherlands.
Putter
Hein
H
Jan Weverling
Gerrit
G
Ter Meulen
Jan
J
Goudsmit
Jaap
J
D000906:Antibodies / Q000627:therapeutic use*; D004196:Disease Outbreaks / Q000517:prevention & control*; D006801:Humans; D017053:Infection Control / Q000379:methods*; D008433:Mathematics; D015233:Models, Statistical; D010343:Patient Admission / Q000706:statistics & numerical data*; D045473:Severe acute respiratory syndrome-related coronavirus / Q000276:immunology*; D045169:Severe Acute Respiratory Syndrome / Q000453:epidemiology* / Q000209:etiology / Q000517:prevention & control*
D000906:Antibodies