S1	(MH "Influenza Vaccine")
S2	(MH "Influenza, Human+/TM/PC/IM/MO/EP")
S3	(MH "Influenza, Human") OR (MH "Influenza A H5N1") OR (MH "Influenza, Pandemic (H1N1) 2009") OR (MH "Influenza, Seasonal")
S4	(MH "Influenza A Virus+")
S5	(MH "Influenzavirus B+")
S6	TI ( influenza* or flu ) OR AB ( influenza* or flu )
S7	S3 or S4 or S5 or S6
S8	(MH "Vaccines+")
S9	(MH "Immunization+")
S10	(MH "Immunization Programs")
S11	TI ( vaccin* or immuni* or inocul* ) OR AB ( vaccin* or immuni* or inocul* )
S12	TI ( aluminium or squalene or mf59 or virosom* ) OR AB ( aluminium or squalene or mf59 or virosom* )
S13	S8 or S9 or S10 or S11 or S12
S14	S7 and S13
S15	S1 or S2 or S14
S16	(MH "Aged+")
S17	(MH "Gerontologic Care")
S18	(MH "Nursing Homes") OR (MH "Residential Facilities")
S19	(MH "Nursing Home Patients")
S20	(MH "Long Term Care")
S21	(MH "Adult")
S22	(MH "Men") OR (MH "Aged, Hospitalized") OR (MH "Women")
S23	TI ( pension* or retire* or adult* or aged or elderly or senior* or geriatric* ) OR AB ( pension* or retire* or adult* or aged or elderly or senior* or geriatric* )
S24	TI ( (old* or age*) N3 (people* or person* or adult* or women* or men* or citizen* or residen*) ) OR AB ( (old* or age*) N3 (people* or pension* or adult* or women* or men* or citizen* or residen*) )
S25	TI ( "aged care" or "nursing home" or "nursing homes" ) OR AB ( "aged care" or "nursing home" or "nursing homes" )
S26	S16 or S17 or S18 or S19 or S20 or S21 or S22 or S23 or S24 or S25
S27	S15 and S26
S28	(MH "Clinical Trials+")
S29	PT clinical trial
S30	TI clinic* trial* OR AB clinic* trial*
S31	TI ( (singl* or doubl* or trebl* or tripl*) N1 (blind* or mask*) ) OR AB ( (singl* or doubl* or trebl* or tripl*) N1 (blind* or mask*) )
S32	(MH "Random Assignment")
S33	(MH "Placebos")
S34	(MH "Quantitative Studies")
S35	TI ( random* or placebo* ) OR AB ( random* or placebo* )
S36	S28 or S29 or S30 or S31 or S32 or S33 or S34 or S35
S37	S27 and S36