You will be shown an abstract from a biomedical research paper. Given this abstract, your task is to extract all unique entities of the following types: ["Outcome", "Participant", "Intervention"].

Please return the output as a JSON object of the format: {"Participant" : ["patients with COPD", ...], "Intervention" : ["Atenolol", ...], "Outcome" : ["blood pressure", ...]}. The keys should be entity types and values should be lists of extracted entities belonging to the corresponding type. If you cannot find entities belonging to a specific type, the value should be [].

Only output the JSON object and do not include any additional text.

Abstract:

Combined typhoid fever and hepatitis A vaccine : comparison of immunogenicity and safety to concomitant monovalent vaccine over 3 years . BACKGROUND The safety and immunogenicity of Viatim , a combined hepatitis A ( HA ) and typhoid fever ( Vi ) vaccine , were compared with the monovalent component vaccines up to and 1 month after a booster dose at 3 years . METHODS Healthy , adult volunteers were randomized to receive Viatim ( group A , n = 179 ) or separate HA and Vi vaccines ( group B , n = 181 ) ; subgroups were boosted after 3 years with Viatim ( groups C and D , n = 56 and 46 , respectively ) . Local and systemic reactions were recorded for 28 days postvaccination . Seroconversion and seroprotection rates and geometric mean antibody concentrations were measured at 14 and 28 days , 1 , 2 , and 3 years postvaccination , and 28 days after the booster dose . RESULTS Local and systemic safety profiles were equivalent between the two groups . Immediate local reactions were infrequent ( 1 in group A and 2 in group B ) . Local reactions , consisting mostly of mild or moderate pain , were least frequent with monovalent HA . Antibody concentrations to both antigens were similar in groups A and B , in which HA seroprotection rates ( > or = 20 mIU/mL ) were respectively , 98.7 % and 100 % at day 28 , and 99.1 % and 99.0 % after 3 years , achieving 100 % after the booster . Vi seroprotection rates ( > or = 1 microg/mL ) of 85.2 % and 84.9 % after 28 days fell to 32.1 % and 35.6 % after 3 years , increasing to 67.3 % and 69.8 % after the booster dose . CONCLUSIONS The combined HA/Vi vaccine , Viatim , had equivalent tolerability and safety and was as rapidly immunogenic as its component monovalent vaccines when given concurrently . A booster dose after 3 years significantly increased antibody levels with some evidence of relative hyporesponsiveness of the typhoid response .
{"Intervention": ["monovalent component vaccines", "Combined typhoid fever and hepatitis A vaccine", "separate HA and Vi vaccines", "combined HA/Vi vaccine", "Viatim", "combined hepatitis A ( HA ) and typhoid fever ( Vi ) vaccine"], "Outcome": ["Local and systemic safety profiles", "mild or moderate pain", "immunogenicity", "seroprotection rates", "Immediate local reactions", "Antibody concentrations", "geometric mean antibody concentrations", "Local reactions", "HA seroprotection rates", "hyporesponsiveness of the typhoid response", "tolerability and safety and was as rapidly immunogenic", "antibody levels", "Seroconversion", "safety"], "Participant": []}