***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
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    Input: A double-blind , r and omized study of inhaled zanamivir for the prevention of influenza in families was conducted . Once a person with a suspected case of influenza was identified ( index patient ) , treatment of all other household members ( contacts ) > or = 5 years old was initiated . Contacts received either 10 mg zanamivir or placebo inhaled once daily for 10 days . Index patients received relief medication only . In total , 487 households ( 242 placebo and 245 zanamivir ) were enrolled , with 1291 contacts r and omly assigned to receive prophylaxis . Four percent of zanamivir versus 19 % of placebo households ( P<.001 ) had at least 1 contact who developed symptomatic , laboratory-confirmed influenza , representing 81 % protective efficacy ( 95 % confidence interval , 64%-90 % ) . Protective efficacy was similarly high for individuals ( 82 % ) and against both influenza types A and B ( 78 % and 85 % , respectively , for households ) . Zanamivir was well tolerated and was effective in preventing influenza types A and B within households where the index patient was not treated BACKGROUND Influenza causes lower respiratory tract complications ( LRTCs ) , particularly bronchitis and pneumonia , in both otherwise healthy adults and those with underlying conditions . The aim of this study was to assess the effect of oseltamivir treatment on the incidence of LRTCs leading to antibiotic treatment and hospitalizations following influenza illness . METHODS We analyzed prospect ively collected data on LRTCs and antibiotic use from 3564 subjects ( age range , 13 - 97 years ) with influenzalike illness enrolled in 10 placebo-controlled , double-blind trials of oseltamivir treatment .  RESULTS In adults and adolescents with a proven influenza illness , oseltamivir treatment reduced overall antibiotic use for any reason by 26.7 % ( 14.0 % vs 19.1 % with placebo ; P<.001 ) and the incidence of influenza-related LRTCs result ing in antibiotic therapy by 55 % ( 4.6 % vs 10.3 % with placebo ; P<.001 ) . In those subjects considered at increased risk of complications , 74 ( 18.5 % ) of 401 placebo recipients developed an LRTC leading to antibiotic use compared with 45 ( 12.2 % ) of 368 oseltamivir recipients ( 34.0 % reduction ; P = .02 ) . Hospitalization for any cause occurred in 18 ( 1.7 % ) of 1063 placebo recipients compared with 9 ( 0.7 % ) of 1350 oseltamivir-treated patients ( 59 % reduction ; P = .02 ) . In contrast , among subjects with an influenzalike illness but without a confirmed influenza infection , the incidence of LRTCs ( 6.7 % vs 5.3 % ) , overall antibiotic use ( 19.7 % vs 19.3 % ) , or hospitalizations ( 1.7 % vs 1.9 % ) was similar between placebo and oseltamivir recipients , respectively . CONCLUSION Oseltamivir treatment of influenza illness reduces LRTCs , antibiotic use , and hospitalization in both healthy and " at-risk " adults We explored the prophylactic activity of zanamivir  after presumed exposure to influenza in the community . After close contacts with index cases of influenza-like illnesses , 575 subjects were r and omized in 4 treatment groups : 144 received placebo , 141 received intranasal zanamivir , 144 received inhaled zanamivir , and 146 received inhaled plus intranasal zanamivir for 5 days . Of 25 subjects ( 4 % ) who developed symptomatic influenza during the 5 days of prophylaxis , 9 ( 36 % ) were in the placebo group , 8 ( 32 % ) were in the intranasal zanamivir group ( odds ratio [ OR ] , 0.90 ; 95 % confidence interval [ CI ] , 0.30 - 2.72 ; P=.855 ) , 3 ( 12 % ) were in the inhaled zanamivir group ( OR , 0.27 ; 95 % CI , 0.07 - 1.05 ; P=.058 ) , and 5 ( 20 % ) were in the inhaled plus intranasal zanamivir group ( OR , 0.52 ; 95 % CI , 0.17 - 1.58 ; P=.247 ) . Short-term treatment with intranasal zanamivir was ineffective . However , inhaled zanamivir treatment reduced the rate of influenza , which was 2%-3 % among zanamivir recipients versus 6 % among placebo recipients . Additional studies assessing a longer duration of postcontact prophylaxis are warranted The antiviral and clinical effects of inhaled zanamivir ( 10 mg twice daily for 5 days , started within the first or second day of a flulike illness ) were evaluated in a r and omized ,  placebo-controlled trial during the 1997 - 1998 influenza season in Canada . Pharyngeal secretions were collected with swabs every 12 h during 6 days , and symptoms were self-evaluated twice daily during 14 days . After only 12 h of treatment ( 1 dose ) , median virus titers decreased by 1.0 log10 TCID50/mL in the  zanamivir group ( n=17 ) , compared with a 0 . 42-log10 increase in the placebo group ( n=10 ; P=.08 ) . This was associated with a 4.5-day ( 47.4 % ) reduction in the median time to alleviation of all significant flu symptoms in the  zanamivir recipients ( P=.03 after adjusting for the initial virus titer and the time between onset of symptoms and treatment ) . Resistance to zanamivir  was not detected in virus isolates by either phenotypic or genotypic assays The efficacy and safety of zanamivir , administered 2x or 4x daily over 5 days , was evaluated in the treatment of influenza infections . A total of 1256 patients entered the study ; 57 % of those r and omized had laboratory-confirmed influenza infection . The primary end point , " alleviation of major symptoms , " was created to evaluate differences in clinical impact . In the overall population with or without influenza infection , zanamivir reduced the median number of days to reach this end point by 1 day ( P=.012 2x daily vs. placebo ; P=.014 4x daily vs. placebo ) . The reduction was greater in patients treated within 30 h of symptom onset , febrile at study entry , and in defined high-risk groups . Zanamivir reduced nights of disturbed sleep , time to resumption of normal activities , and use of symptom relief medications . It was well tolerated . These results suggest that zanamivir can significantly reduce the duration and overall symptomatic effect of influenza We determined the efficacy of postexposure prophylaxis ( PEP ) and treatment of ill index cases with oseltamivir , in an attempt to prevent influenza transmission in households , in a study conducted in 277 households with 298 index cases ( 62 % with laboratory-confirmed influenza ) and 812 contacts aged > or = 1 year . Contacts were r and omized by household to receive treatment ( 5 days ; n=402 ) , if illness developed , or PEP for 10 days ( n=410 ) , and the number of households with at least 1 contact developing laboratory-confirmed influenza was measured . PEP provided a protective efficacy of 58.5 % ( 95 % confidence interval [ CI ] , 15.6%-79.6 % ; P=.0114 ) for households against proven influenza and 68.0 % ( 95 % CI , 34.9%-84.2 % ; P=.0017 ) for individual contacts , compared with treatment of index cases alone . No oseltamivir-resistant variants were detected in treated index cases or contacts . PEP of household contacts of those with influenza reduces the secondary spread of influenza in families when the initial household case is treated BACKGROUND Influenza affects many people worldwide each year and has many troublesome symptoms . We investigated the efficacy and safety of the inhaled antiviral agent zanamivir as a treatment for influenza A and B infection . METHODS In a r and omised , double-blind , placebo-controlled trial , we recruited 455 patients aged 12 years and older with influenza-like symptoms of 36 h duration or less who lived in Australia , New Zeal and , and South Africa . Eligible patients were r and omly assigned 10 mg inhaled zanamivir ( n=227 ) or placebo ( n=228 ) twice daily for 5 days . All patients recorded symptoms on diary cards four times daily during treatment and twice daily for 9 days after treatment . We analysed all patients by intention to treat , influenza-positivity , and high risk of developing complications . FINDINGS Compared with placebo , zanamavir relieved influenza symptoms a median of 1.5 days earlier in the intention-to-treat ( p=0.011 ) and influenza-positive ( p=0.004 ) population s , and 2 days earlier in patients who were febrile at entry [ corrected ] . In high-risk patients treated with zanamivir , symptoms were alleviated a median of 2.5 days earlier ( p=0.048 ) , fewer had complications ( p=0.004 ) , and fewer used complication-associated antibiotics ( p=0.025 ) compared with placebo . The adverse event profiles were similar for zanamivir and placebo . INTERPRETATION Zanamivir was well-tolerated and effective in decreasing the duration and severity of symptoms . Complications were also decreased in high-risk patients but these findings need to be confirmed in future studies due to the limited number of patients [ corrected ] We have investigated the long-term prophylactic efficacy and safety of oseltamivir phosphate ( Ro64 - 0796 ) , an orally bioavailable prodrug of novel , potent and selective type A and type B influenzavirus neuraminidase inhibitor , when Ro64 - 0796 was administered orally to the healthy volunteers . Participants older than 16 year-old were r and omly assigned to either Ro64 - 0796 75 mg once daily group or matching placebo group for six weeks . A total of 308 participants ( Placebo group ; 153 and Ro64 - 0796 group ; 155 ) were enrolled in this trial . The primary variable of efficacy , incidence of laboratory-confirmed influenzavirus infected subjects accompanied by both fever of 37.5 degrees C or higher and at least two influenza symptoms ( group 1 ) were 1.3 % in Ro64 - 0796 group in contrast with 8.5 % in placebo group , inducing 85 % inhibition of infection ( p = 0.00323 , Fisher 's exact test ) . As secondary variable , incidence of laboratory-confirmed influenzavirus infected subjects who lack either fever ( 37.5 degrees C or higher ) or at least two influenza symptoms ( group 2 ) and incidence of asymptomatic infected subjects ( group 3 ) were tend to decrease in Ro64 - 0796 group , and finally cumulative inhibition rate was 76 % in group 1 + 2 combined ( p = 0.000891 . Fisher 's exact test ) , and 63 % in group 1 + 2 + 3 combined ( p = 0.002150 , Fisher 's exact test ) . As for the safety evaluations , Ro64 - 0796 was well tolerated but was associated with gastrointestinal disorders such as nausea and vomiting which were mild and allowable for the clinical use . There was no abnormal change attributable to Ro64 - 0796 application in the clinical laboratory tests as well as the physiological tests . Our results demonstrate that oseltamivir is safe and effective for the prevention of influenza BACKGROUND The sialic acid analogue zanamivir ( GG167 ) is a selective inhibitor of influenza A and B virus neuraminidases . These viral enzymes are essential for the release of virus from infected cells , and they may also reduce the inactivation of virus by respiratory secretions . When administered experimentally directly to the respiratory tract , zanamivir has potent antiviral effects . We assessed the therapeutic activity of zanamivir in adults with acute influenza . METHODS We conducted separate r and omized , double-blind studies in 38 centers in North America and 32 centers in Europe during the influenza season of 1994 - 1995 . A total of 417 adults with influenza-like illness of < or = 48 hours ' duration were r and omly assigned to one of three treatments : 6.4 mg of zanamivir by intranasal spray plus 10 mg by inhalation , 10 mg of zanamivir by inhalation plus placebo spray , or placebo by both routes . Treatments were self-administered twice daily for five days . RESULTS Of 262 patients with confirmed influenza-virus infection ( 63 percent of all patients ) , the median length of time to 
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Conclusion Neuraminidase inhibitors have modest effectiveness against the symptoms of influenza in otherwise healthy adults .
The drugs are effective postexposure against laboratory confirmed influenza , but this is a small component of influenza-like illness , so for this outcome neuraminidase inhibitors are not effective .
Neuraminidase inhibitors might be regarded as optional for reducing the symptoms of seasonal influenza .