***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 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: Transplacentally acquired antibody to influenza A virus was measured by a microneutralization test and a radioimmunoprecipitation assay in cord blood obtained from infants at a large urban county hospital in 1975 - 1978 . R and om sample s tested before epidemic periods were a measure of susceptibility of the population . Twenty-six infants from whom cord sera were available had culture-documented infections with influenza A/Victoria ( H3N2 ) virus when younger than four months . The direct correlation between age at the time of infection and level of antibody measured in cord serum ( P less than 0.002 ) suggested a protective effect of transplacentally acquired antibody . None of fourteen acute-phase serum specimens obtained early in the course of culture-positive infections of young infants had detectable antibody to influenza A viral hemagglutinin by the sensitive radioimmunoprecipitation test . Because passively transferred maternal antibody to influenza virus may prevent symptomatic infection in young infants , vaccination of pregnant women could be beneficial BACKGROUND There are limited data on the efficacy of vaccination against confirmed influenza in pregnant women with and those without human immunodeficiency virus ( HIV ) infection and protection of their infants . METHODS We conducted two double-blind , r and omized , placebo-controlled trials of trivalent inactivated influenza vaccine ( IIV3 ) in South Africa during 2011 in pregnant women infected with HIV and during 2011 and 2012 in pregnant women who were not infected . The immunogenicity , safety , and efficacy of IIV3 in pregnant women and their infants were evaluated until 24 weeks after birth . Immune responses were measured with a hemagglutination inhibition ( HAI ) assay , and influenza was diagnosed by means of reverse-transcriptase-polymerase-chain-reaction ( RT-PCR ) assays of respiratory sample s. RESULTS The study cohorts included 2116 pregnant women who were not infected with HIV and 194 pregnant women who were infected with HIV . At 1 month after vaccination , seroconversion rates and the proportion of participants with HAI titers of 1:40 or more were higher among IIV3 recipients than among placebo recipients in both cohorts . Newborns of IIV3 recipients also had higher HAI titers than newborns of placebo recipients . The attack rate for RT-PCR-confirmed influenza among both HIV-uninfected placebo recipients and their infants was 3.6 % . The attack rates among HIV-uninfected IIV3 recipients and their infants were 1.8 % and 1.9 % , respectively , and the respective vaccine-efficacy rates were 50.4 % ( 95 % confidence interval [ CI ] , 14.5 to 71.2 ) and 48.8 % ( 95 % CI , 11.6 to 70.4 ) . Among HIV-infected women , the attack rate for placebo recipients was 17.0 % and the rate for IIV3 recipients was 7.0 % ; the vaccine-efficacy rate for these IIV3 recipients was 57.7 % ( 95 % CI , 0.2 to 82.1 ) . CONCLUSIONS Influenza vaccine was immunogenic in HIV-uninfected and HIV-infected pregnant women and provided partial protection against confirmed influenza in both groups of women and in infants who were not exposed to HIV . ( Funded by the Bill and Melinda Gates Foundation and others ; Clinical Trials.gov numbers , NCT01306669 and NCT01306682 . ) Background Pregnant women were suspected to be at particular risk when H1N1pnd09 influenza became p and emic in 2009 . Our primary objective was to compare the immune responses conferred by MF59 ® -adjuvanted vaccine ( Focetria ® ) in H1N1pnd09-naïve pregnant and non-pregnant women . The secondary aims were to compare influences of dose and adjuvant on the immune response . Methods The study was nested in the Copenhagen Prospect i ve Studies on Asthma in Childhood ( COPSAC2010 ) pregnancy cohort in 2009 - 2010 and conducted as a single-blinded block-r and omised [ 1∶1∶1 ] controlled clinical trial in pregnant women after gestational week 20 : ( 1 ) 7.5 µg H1N1pnd09 antigen with MF59-adjuvant ( Pa7.5 µg ) ; ( 2 ) 3.75 µg antigen half MF59-adjuvanted ( Pa3.75 µg ) ; ( 3 ) 15 µg antigen unadjuvanted ( P15 µg ) ; and  in non-pregnant women receiving ( 4 ) 7.5 µg antigen full adjuvanted ( NPa7.5 µg ) . Blood sample s were collected at baseline , 3 weeks , 3 and 10 months after vaccination , adverse events were recorded prospect ively . Results 58 pregnant women were allocated to Pa7.5 µg and 149 non-pregnant women were recruited to NPa7.5 µg .  The sero-conversion rate was significantly increased in non-pregnant ( NPa7.5 µg ) compared with pregnant ( Pa7.5 µg ) women ( OR = 2.48 [ 1.03–5.95 ] , p = 0.04 ) and geometric mean titers trended towards being higher , but this difference was not statistically significant ( ratio 1.27 [ 0.85–1.93 ] , p = 0.23 ) . The significant titer increase rate showed no difference between pregnant ( Pa7.5 µg ) and non-pregnant ( NPa7.5 µg ) groups ( OR = 0.49 [ 0.13–1.85 ] , p = 0.29 ) . Conclusion Our study suggests the immune response to the 7.5 µg MF59-adjuvanted Focetria ® H1N1pnd09 vaccine in pregnant women may be diminished compared with non-pregnant women . Trial Registration Clinical Trials.gov NCT01012557 BACKGROUND Although pregnant women are at increased risk of severe illness following influenza infection , there is relatively little information on the immunogenicity of influenza vaccines administered during pregnancy . METHODS We conducted a clinical trial that enrolled 120 pregnant women in which participants were r and omly assigned to receive an inactivated 2009 H1N1 influenza vaccine containing either 25 μg or 49 μg of hemagglutinin ( HA ) in a 2-dose series with a 21-day period between administration of the first and second doses . RESULTS Following the first vaccination , HA inhibition ( HAI ) titers of ≥1:40 were detected in 93 % ( 95 % confidence interval [ CI ] , 82%-98 % ) of subjects who received the 25-μg dose and 97 % ( 95 % CI , 88%-100 % ) of subjects receiving the 49-μg dose . In cord blood sample s , HAI titers of ≥1:40 were found in 87 % ( 95 % CI , 73%-96 % ) of sample s from the 25-μg dose group and in 89 % ( 95 % CI , 76%-96 % ) from the 49-μg dose group . Microneutralization titers tended to be higher than HAI titers , but the patterns of response were similar . CONCLUSIONS In pregnant women , 1 dose of an inactivated 2009 H1N1 influenza vaccine containing 25 μg of HA elicited an antibody response typically associated with protection against influenza infection . Efficient transplacental transfer of antibody was also documented Background . Pregnant women are a high-risk group for influenza-associated complications and hospitalizations . Methods . To examine the immunogenicity of a monovalent 2009 influenza A ( H1N1 ) vaccine among pregnant women , a prospect i ve cohort study was performed at 2 medical institutes of obstetrics in Japan . One hundred fifty subjects received 2 subcutaneous doses of vaccine 3 weeks apart . The hemagglutination inhibition antibody titer was measured in serum sample s collected at 3 time points : before vaccination , 3 weeks after the first dose , and 4 weeks after the second dose . Results . The first dose of vaccine induced a ≥10-fold rise in the average level of antibody . The seroresponse rate ( ≥4-fold rise ) was 91 % , and the seroprotection rate ( postvaccination titer ≥1:40 ) was 89 % . The second dose of vaccine conferred little additional induction of antibodies . Similar immune responses were observed irrespective of body mass index before pregnancy , trimester , or age at vaccination . However , lesser immune response was shown in subjects who had received the 2009–2010 seasonal influenza vaccine before the H1N1 vaccination . Conclusions . A single dose of vaccine induced an adequately protective level of immunity in pregnant women . The potential interference with seasonal vaccination requires a more thorough investigation to prepare for future influenza p and emics BACKGROUND Pregnant women are at increased risk of complications following influenza infection . Vaccination is the most effective preventive strategy . This survey aim ed to determine the levels of uptake of influenza vaccine in pregnant women in Western Australia ( WA ) , the proportion of women offered vaccination as part of antenatal care , and women 's attitudes toward influenza vaccination in pregnancy . METHODS Computer assisted telephone interviews were conducted with 416 r and omly selected women who were pregnant during the 2012 influenza vaccination season . RESULTS  Influenza vaccination coverage was 23 % . Predictors of vaccination included believing that vaccination is safe for the infant , having been recommended vaccination by an antenatal care provider , and attending a general practitioner for most antenatal care . The majority ( 74 % ) of unvaccinated women reported that they would have the vaccine if their antenatal care provider recommended it . DISCUSSION General practitioners lead the way in antenatal influenza vaccination in WA . Vaccination coverage can be improved if recommending and offering influenza vaccination becomes a routine part of antenatal care This study aim ed to comprehensively describe inflammatory responses to trivalent influenza virus vaccine ( TIV ) among pregnant women and determine whether responses differ compared to non‐pregnancy OBJECTIVE To assess the effect of seasonal influenza vaccination during pregnancy on laboratory-confirmed influenza in infants to 6 months of age . DESIGN Nonr and omized , prospect i ve , observational cohort study . SETTING Navajo and White Mountain Apache Indian reservations , including 6 hospitals on the Navajo reservation and 1 on the White Mountain Apache reservation . PARTICIPANTS A total of 1169 mother-infant pairs with mothers who delivered an infant during 1 of 3 influenza seasons . MAIN EXPOSURE Maternal seasonal influenza vaccination . MAIN OUTCOME MEASURES In infants , laboratory-confirmed influenza , influenza-like illness ( ILI ) , ILI hospitalization , and influenza hemagglutinin inhibition antibody titers . RESULTS A total of 1160 mother-infant pairs had serum collected and were included in the analysis . Among infants , 193 ( 17 % ) had an ILI hospitalization , 412 ( 36 % ) had only an ILI outpatient visit , and 555 ( 48 % ) had no ILI episodes . The ILI incidence rate was 7.2 and 6.7 per 1000 person-days for infants born to unvaccinated and vaccinated women , respectively . There was a 41 % reduction in the risk of laboratory-confirmed influenza virus infection ( relative risk , 0.59 ; 95 % confidence interval , 0.37 - 0.93 ) and a 39 % reduction in the risk of ILI hospitalization ( relative risk , 0.61 ; 95 % confidence interval , 0.45 - 0.84 ) for infants born to influenza-vaccinated women compared with infants born to unvaccinated mothers . Infants born to influenza-vaccinated women had significantly higher hemagglutinin inhibition antibody titers at birth and at 2 to 3 months of age than infants of unvaccinated mothers for all 8 influenza virus strains investigated . CONCLUSIONS Maternal influenza vaccination was significantly associated with reduced risk of influenza virus infection and hospitalization for an ILI up to 6 months of age and increased influenza antibody titers in infants through 2 to 3 months of age OBJECTIVE : To evaluate the efficacy of double vaccination with the 2009 p and emic influenza A ( H1N1 ) vaccine  during pregnancy . METHODS : A study of the 2009 H1N1 vaccine was conducted in 128 pregnant women , who were between 8 and 32 weeks of gestation in October 2009 , to monitor the immune response to vaccination and the change in antibody positivity rate and to assess the imm 
    Output:
    
This review provides comparative analysis of the effect of vaccination timing on maternal immunogenicity and protection of the infant that is informative and relevant to current vaccine scheduling for pregnant women