human
***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: Background . A 23-valent unconjugated pneumococcal polysaccharide vaccine ( 23vP ) , routinely administered at the age of 65 , has limited effectiveness , and revaccination induces attenuated antibody responses . It is not known whether pneumococcal polysaccharide-protein conjugated vaccines ( PCV ) , although highly effective in infants , offer any immunological advantages over 23vP in adults . Methods . We immunized adults with schedules combining both PCV and 23vP  and investigated B-cell responses to establish whether PCV7 ( a 7-valent PCV ) induced T-dependent responses in adults , to assess the role of memory B cells in 23vP-induced antibody hyporesponsiveness , and to identify the B-cell subtypes involved . Results . A single dose of PCV7 induced significant increases in serotype-specific memory B-cell population s in peripheral blood indicating a T-dependent response . Conversely , immunization with 23vP result ed in a decrease in memory B-cell frequency . Furthermore , memory B-cell responses to subsequent immunization with PCV7 , when given after 23vP , were attenuated . Notably , B1b cells , a subset important in protecting mice against pneumococci , were also depleted following immunization with 23vP in humans . Conclusions . This study indicates that PCV7 may have an immunological advantage over 23vP in adults and that 23vP-induced depletion of memory and B1b-cell subsets may provide a basis for antibody hyporesponsiveness and the limited effectiveness of 23vP. Clinical Trials Registration . IS RCT N : 78768849 BACKGROUND Older adults are at high risk of developing invasive pneumococcal disease , but the optimal timing and number of vaccine doses needed to prevent disease among this group are unknown . We compared revaccination with 23-valent pneumococcal polysaccharide vaccine ( PN23 ) with primary vaccination for eliciting initial and persistent functional antibody responses . METHODS Subjects aged > or = 65 years were enrolled .  Functional ( opsonic ) and total immunoglobulin ( Ig ) G antibody levels were measured following either PN23 primary vaccination ( n = 60 ) or revaccination 3 - 5 years after receiving a first PN23 vaccination ( n = 60 ) . Antibody against vaccine serotypes 4 , 14 , and 23F was measured at prevaccination ( day 0 ) , 30 days after vaccination , and 5 years after vaccination . RESULTS By day 30 , both primary vaccination and revaccination induced significant increases in opsonic and IgG antibody levels . Day 30 levels following revaccination were slightly lower but not significantly different than those after primary vaccination . Year 5 levels were similar in both groups and remained significantly higher than prevaccination levels for primary vaccination subjects . There was good agreement between postvaccination opsonic and IgG antibody levels . CONCLUSIONS Revaccination of older adults with PN23 was comparable to primary vaccination for inducing elevated and persistent functional and IgG antibody responses CONTEXT Revaccination of healthy adults with pneumococcal polysaccharide vaccine ( PPV )  within several years of first vaccination has been associated with a higher than expected frequency and severity of local injection site reactions . The risk of adverse events associated with revaccination of elderly and chronically ill persons 5 or more years after first vaccination , as is currently recommended , has not been well defined . OBJECTIVE To determine whether revaccination with PPV at least 5 years after first vaccination is associated with more frequent or more serious adverse events than those following first vaccination . DESIGN Comparative intervention study conducted between April 1996 and August 1997 . PARTICIPANTS Persons aged 50 to 74 years either who had never been vaccinated with PPV ( n = 901 ) or who had been vaccinated once at least 5 years prior to enrollment ( n = 513 ) . INTERVENTION PPV vaccination . MAIN OUTCOME MEASURES Postvaccination local injection site reactions and prevaccination concentrations of type-specific antibodies . RESULTS Those who were revaccinated were more likely than those who received their first vaccinations to report a local injection site reaction of at least 10.2 cm ( 4 in ) in diameter within 2 days of vaccination : 11 % ( 55/513 ) vs 3 % ( 29/901 ) ( relative risk [ RR ] , 3.3 ; 95 % confidence interval [ CI ] , 2.1 - 5.1 ) . These reactions resolved by a median of 3 days following vaccination . The highest rate was among revaccinated patients who were immunocompetent and did not have chronic illness : 15 % ( 33/228 ) compared with 3 % ( 10/337 ) among comparable patients receiving their first vaccinations ( RR , 4.9 ; 95 % CI , 2.4 - 9.7 ) . The risk of these local reactions was significantly correlated with prevaccination geometric mean antibody concentrations . CONCLUSIONS Physicians and patients should be aware that self-limited local injection site reactions occur more frequently following revaccination compared with first vaccination ; however , this risk does not represent a contraindication to revaccination with PPV for recommended groups On August 13 , 2014 , the Advisory Committee on Immunization Practice s ( ACIP ) recommended routine use of 13-valent pneumococcal conjugate vaccine ( PCV13 [ Prevnar 13 , Wyeth Pharmaceuticals , Inc. , a subsidiary of Pfizer Inc. ] ) among adults aged ≥65 years .  PCV13 should be administered in series with the 23-valent pneumococcal polysaccharide vaccine ( PPSV23 [ Pneumovax23 , Merck & Co. , Inc. ] ) , the vaccine currently recommended for adults aged ≥65 years . PCV13 was approved by the Food and Drug Administration ( FDA ) in late 2011 for use among adults aged ≥50 years . In June 2014 , the results of a r and omized placebo-controlled trial evaluating efficacy of PCV13 for preventing community-acquired pneumonia among approximately 85,000 adults aged ≥65 years with no prior pneumococcal vaccination history ( CAPiTA trial ) became available and were presented to ACIP . The evidence supporting PCV13 vaccination of adults was evaluated using the Grading of Recommendations , Assessment , Development , and Evaluation ( GRADE ) framework and determined to be type 2 ( moderate level of evidence ) ; the recommendation was categorized as a Category A recommendation . This report outlines the new recommendations for PCV13 use , provides guidance for use of PCV13 and PPSV23 among adults aged ≥65 years , and summarizes the evidence considered by ACIP to make this recommendation BACKGROUND The benefits of using the 23-valent pneumococcal polysaccharide vaccine ( PPV23 ) are controversial . This study assessed clinical effectiveness of PPV23 in preventing community-acquired pneumonia ( CAP ) among the general population aged ≥ 60 years . METHODS This was a population -based cohort study involving 27 204 individuals aged ≥ 60 years in Tarragona , Spain , who were prospect ively followed from 1 December 2008 until 30 November 2011 . Primary outcomes were hospitalization for pneumococcal CAP ( bacteremic and nonbacteremic cases ) and all-cause CAP . All CAP cases were radiographically confirmed and vali date d by checking clinical records . Cox regression was used to evaluate the association between pneumococcal vaccination and the risk of each outcome . RESULTS Cohort members were followed for a total of 76 033 person-years ( 29 065 person-years for vaccinated subjects ) . Incidence rates ( per 1000 person-years ) were 0.21 for bacteremic pneumococcal CAP ( 0.14 vs 0.26 among vaccinated and unvaccinated subjects , respectively ) , 1.45 for nonbacteremic pneumococcal CAP ( 1.46 vs 1.44 ) , and 7.51 for all-cause CAP ( 7.19 vs 7.71 ) . In primary analyses including all cohort members , PPV23 did not appear to be effective against any analyzed outcome . However , a beneficial effect emerged in sensitive and stratified analyses . After multivariable adjustments , as compared with those never vaccinated , recent vaccination with PPV23 ( < 5 years ago ) was associated with reduced risks of bacteremic pneumococcal CAP ( hazard ratio [ HR ] , 0.38 ; 95 % confidence interval [ CI ] , .09 - 1.68 ) , nonbacteremic pneumococcal CAP ( HR , 0.52 ; 95 % CI , .29-.92 ) , overall pneumococcal CAP ( HR , 0.49 ; 95 % CI , .29-.84 ) , and all-cause CAP ( HR , 0.75 ; 95 % CI , .58-.98 ) . CONCLUSIONS Our data support a protective effect of recent PPV23 vaccination ( within previous 5 years ) against both pneumococcal and all-cause CAP Renal transplant recipients are at increased risk of developing invasive pneumococcal diseases but may have poor response to the 23-valent pneumococcal polysaccharide vaccine ( PPV ) . It may be possible to enhance immunogenicity by priming with 7-valent pneumococcal conjugate vaccine ( 7vPnC ) and boosting with PPV 1 year later . In a r and omized single-blind , controlled study , adult recipients of renal transplants received either 7nPVC or PPV followed by PPV 1 year later . The vaccine response was defined as 2-fold increase in antibody concentration from baseline and an absolute post-vaccination values ≥1 µg/ml . The primary endpoint was vaccine response of the primed group ( 7vPnC/PPV ) compared with single PPV vaccination . Antibody concentrations for 10 serotypes were measured at baseline , 8 weeks after first vaccination , before second vaccination , and 8 weeks after second vaccination . Of 320 screened patients , 80 patients were r and omized and 62 completed the study . Revaccination with PPV achieved no significant increase of immune response in the 7vPnC/PPV group compared with the single PPV  recipients A response to at least 1 serotype was seen in 77.1 % of patients who received 7vPnC and 93.1 % of patients who received PPV ( P = 0.046 ) . After second vaccination response to at least 1 serotype was seen in 87.5 % patients of 7vPnC/PPV group and 87.1 % patients of PPV group ( non significant p ) . The median number of serotypes eliciting a response was 3.5 ( 95 % CI 2.5–4.5 ) in the 7vPnC/PPV group versus 5 ( 95 % CI 3.9–6.1 ) in the PPV group ( non-significant p ) . Immunogenicity of pneumococcal vaccination was not enhanced by the prime – boost strategy compared with vaccination with PPV alone . Administration of a single dose of PPV should continue to be the st and ard of care for adult recipients of renal transplants . Trial Registration EudraCT 2007 - 004590 - 25 BACKGROUND Following vaccination with 23-valent pneumococcal polysaccharide vaccine ( PPV ) , pneumococcal antibody levels decline to prevaccination levels within 6 - 10 years . The Advisory Committee on Immunization Practice s does not recommend routine revaccination because data on the safety and effectiveness of additional doses are insufficient . METHODS To determine whether medically attended adverse events occur more frequently after the third dose of PPV than after the first or second dose , we performed a retrospective review of medical records from a computer data base for health care facilities that serve more than one-half of the Alaska Native population . All persons who had received > or = 3 PPV doses ( n = 179 ) were included in the review , as were a r and omly selected comparison group of 181 persons who had received 1 or 2 doses . RESULTS Only 1 ( 0.55 % ) of 179 persons who had received > or = 3 PPV doses and 4 ( 2.76 % ) of 181 persons in the comparison group had a medically attended adverse event , and no severe adverse events were recorded . CONCLUSION We found no difference in the risk of medically attended adverse events following > or = 3 doses of PPV , compared with 1 or 2 doses BACKGROUND Unlike free polysaccharide vaccines , pneumococcal polysaccharide conjugate vaccines ( PCVs ) induce a T cell-dependent immune response and have the potential to provide an extended duration of protection with repeated vaccinations . METHODS This was an extension of a previous study in pneumococcal  vaccine-naïve adults 
    Output:
    
agent
***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: Background . A 23-valent unconjugated pneumococcal polysaccharide vaccine ( 23vP ) , routinely administered at the age of 65 , has limited effectiveness , and revaccination induces attenuated antibody responses . It is not known whether pneumococcal polysaccharide-protein conjugated vaccines ( PCV ) , although highly effective in infants , offer any immunological advantages over 23vP in adults . Methods . We immunized adults with schedules combining both PCV and 23vP  and investigated B-cell responses to establish whether PCV7 ( a 7-valent PCV ) induced T-dependent responses in adults , to assess the role of memory B cells in 23vP-induced antibody hyporesponsiveness , and to identify the B-cell subtypes involved . Results . A single dose of PCV7 induced significant increases in serotype-specific memory B-cell population s in peripheral blood indicating a T-dependent response . Conversely , immunization with 23vP result ed in a decrease in memory B-cell frequency . Furthermore , memory B-cell responses to subsequent immunization with PCV7 , when given after 23vP , were attenuated . Notably , B1b cells , a subset important in protecting mice against pneumococci , were also depleted following immunization with 23vP in humans . Conclusions . This study indicates that PCV7 may have an immunological advantage over 23vP in adults and that 23vP-induced depletion of memory and B1b-cell subsets may provide a basis for antibody hyporesponsiveness and the limited effectiveness of 23vP. Clinical Trials Registration . IS RCT N : 78768849 BACKGROUND Older adults are at high risk of developing invasive pneumococcal disease , but the optimal timing and number of vaccine doses needed to prevent disease among this group are unknown . We compared revaccination with 23-valent pneumococcal polysaccharide vaccine ( PN23 ) with primary vaccination for eliciting initial and persistent functional antibody responses . METHODS Subjects aged > or = 65 years were enrolled .  Functional ( opsonic ) and total immunoglobulin ( Ig ) G antibody levels were measured following either PN23 primary vaccination ( n = 60 ) or revaccination 3 - 5 years after receiving a first PN23 vaccination ( n = 60 ) . Antibody against vaccine serotypes 4 , 14 , and 23F was measured at prevaccination ( day 0 ) , 30 days after vaccination , and 5 years after vaccination . RESULTS By day 30 , both primary vaccination and revaccination induced significant increases in opsonic and IgG antibody levels . Day 30 levels following revaccination were slightly lower but not significantly different than those after primary vaccination . Year 5 levels were similar in both groups and remained significantly higher than prevaccination levels for primary vaccination subjects . There was good agreement between postvaccination opsonic and IgG antibody levels . CONCLUSIONS Revaccination of older adults with PN23 was comparable to primary vaccination for inducing elevated and persistent functional and IgG antibody responses CONTEXT Revaccination of healthy adults with pneumococcal polysaccharide vaccine ( PPV )  within several years of first vaccination has been associated with a higher than expected frequency and severity of local injection site reactions . The risk of adverse events associated with revaccination of elderly and chronically ill persons 5 or more years after first vaccination , as is currently recommended , has not been well defined . OBJECTIVE To determine whether revaccination with PPV at least 5 years after first vaccination is associated with more frequent or more serious adverse events than those following first vaccination . DESIGN Comparative intervention study conducted between April 1996 and August 1997 . PARTICIPANTS Persons aged 50 to 74 years either who had never been vaccinated with PPV ( n = 901 ) or who had been vaccinated once at least 5 years prior to enrollment ( n = 513 ) . INTERVENTION PPV vaccination . MAIN OUTCOME MEASURES Postvaccination local injection site reactions and prevaccination concentrations of type-specific antibodies . RESULTS Those who were revaccinated were more likely than those who received their first vaccinations to report a local injection site reaction of at least 10.2 cm ( 4 in ) in diameter within 2 days of vaccination : 11 % ( 55/513 ) vs 3 % ( 29/901 ) ( relative risk [ RR ] , 3.3 ; 95 % confidence interval [ CI ] , 2.1 - 5.1 ) . These reactions resolved by a median of 3 days following vaccination . The highest rate was among revaccinated patients who were immunocompetent and did not have chronic illness : 15 % ( 33/228 ) compared with 3 % ( 10/337 ) among comparable patients receiving their first vaccinations ( RR , 4.9 ; 95 % CI , 2.4 - 9.7 ) . The risk of these local reactions was significantly correlated with prevaccination geometric mean antibody concentrations . CONCLUSIONS Physicians and patients should be aware that self-limited local injection site reactions occur more frequently following revaccination compared with first vaccination ; however , this risk does not represent a contraindication to revaccination with PPV for recommended groups On August 13 , 2014 , the Advisory Committee on Immunization Practice s ( ACIP ) recommended routine use of 13-valent pneumococcal conjugate vaccine ( PCV13 [ Prevnar 13 , Wyeth Pharmaceuticals , Inc. , a subsidiary of Pfizer Inc. ] ) among adults aged ≥65 years .  PCV13 should be administered in series with the 23-valent pneumococcal polysaccharide vaccine ( PPSV23 [ Pneumovax23 , Merck & Co. , Inc. ] ) , the vaccine currently recommended for adults aged ≥65 years . PCV13 was approved by the Food and Drug Administration ( FDA ) in late 2011 for use among adults aged ≥50 years . In June 2014 , the results of a r and omized placebo-controlled trial evaluating efficacy of PCV13 for preventing community-acquired pneumonia among approximately 85,000 adults aged ≥65 years with no prior pneumococcal vaccination history ( CAPiTA trial ) became available and were presented to ACIP . The evidence supporting PCV13 vaccination of adults was evaluated using the Grading of Recommendations , Assessment , Development , and Evaluation ( GRADE ) framework and determined to be type 2 ( moderate level of evidence ) ; the recommendation was categorized as a Category A recommendation . This report outlines the new recommendations for PCV13 use , provides guidance for use of PCV13 and PPSV23 among adults aged ≥65 years , and summarizes the evidence considered by ACIP to make this recommendation BACKGROUND The benefits of using the 23-valent pneumococcal polysaccharide vaccine ( PPV23 ) are controversial . This study assessed clinical effectiveness of PPV23 in preventing community-acquired pneumonia ( CAP ) among the general population aged ≥ 60 years . METHODS This was a population -based cohort study involving 27 204 individuals aged ≥ 60 years in Tarragona , Spain , who were prospect ively followed from 1 December 2008 until 30 November 2011 . Primary outcomes were hospitalization for pneumococcal CAP ( bacteremic and nonbacteremic cases ) and all-cause CAP . All CAP cases were radiographically confirmed and vali date d by checking clinical records . Cox regression was used to evaluate the association between pneumococcal vaccination and the risk of each outcome . RESULTS Cohort members were followed for a total of 76 033 person-years ( 29 065 person-years for vaccinated subjects ) . Incidence rates ( per 1000 person-years ) were 0.21 for bacteremic pneumococcal CAP ( 0.14 vs 0.26 among vaccinated and unvaccinated subjects , respectively ) , 1.45 for nonbacteremic pneumococcal CAP ( 1.46 vs 1.44 ) , and 7.51 for all-cause CAP ( 7.19 vs 7.71 ) . In primary analyses including all cohort members , PPV23 did not appear to be effective against any analyzed outcome . However , a beneficial effect emerged in sensitive and stratified analyses . After multivariable adjustments , as compared with those never vaccinated , recent vaccination with PPV23 ( < 5 years ago ) was associated with reduced risks of bacteremic pneumococcal CAP ( hazard ratio [ HR ] , 0.38 ; 95 % confidence interval [ CI ] , .09 - 1.68 ) , nonbacteremic pneumococcal CAP ( HR , 0.52 ; 95 % CI , .29-.92 ) , overall pneumococcal CAP ( HR , 0.49 ; 95 % CI , .29-.84 ) , and all-cause CAP ( HR , 0.75 ; 95 % CI , .58-.98 ) . CONCLUSIONS Our data support a protective effect of recent PPV23 vaccination ( within previous 5 years ) against both pneumococcal and all-cause CAP Renal transplant recipients are at increased risk of developing invasive pneumococcal diseases but may have poor response to the 23-valent pneumococcal polysaccharide vaccine ( PPV ) . It may be possible to enhance immunogenicity by priming with 7-valent pneumococcal conjugate vaccine ( 7vPnC ) and boosting with PPV 1 year later . In a r and omized single-blind , controlled study , adult recipients of renal transplants received either 7nPVC or PPV followed by PPV 1 year later . The vaccine response was defined as 2-fold increase in antibody concentration from baseline and an absolute post-vaccination values ≥1 µg/ml . The primary endpoint was vaccine response of the primed group ( 7vPnC/PPV ) compared with single PPV vaccination . Antibody concentrations for 10 serotypes were measured at baseline , 8 weeks after first vaccination , before second vaccination , and 8 weeks after second vaccination . Of 320 screened patients , 80 patients were r and omized and 62 completed the study . Revaccination with PPV achieved no significant increase of immune response in the 7vPnC/PPV group compared with the single PPV  recipients A response to at least 1 serotype was seen in 77.1 % of patients who received 7vPnC and 93.1 % of patients who received PPV ( P = 0.046 ) . After second vaccination response to at least 1 serotype was seen in 87.5 % patients of 7vPnC/PPV group and 87.1 % patients of PPV group ( non significant p ) . The median number of serotypes eliciting a response was 3.5 ( 95 % CI 2.5–4.5 ) in the 7vPnC/PPV group versus 5 ( 95 % CI 3.9–6.1 ) in the PPV group ( non-significant p ) . Immunogenicity of pneumococcal vaccination was not enhanced by the prime – boost strategy compared with vaccination with PPV alone . Administration of a single dose of PPV should continue to be the st and ard of care for adult recipients of renal transplants . Trial Registration EudraCT 2007 - 004590 - 25 BACKGROUND Following vaccination with 23-valent pneumococcal polysaccharide vaccine ( PPV ) , pneumococcal antibody levels decline to prevaccination levels within 6 - 10 years . The Advisory Committee on Immunization Practice s does not recommend routine revaccination because data on the safety and effectiveness of additional doses are insufficient . METHODS To determine whether medically attended adverse events occur more frequently after the third dose of PPV than after the first or second dose , we performed a retrospective review of medical records from a computer data base for health care facilities that serve more than one-half of the Alaska Native population . All persons who had received > or = 3 PPV doses ( n = 179 ) were included in the review , as were a r and omly selected comparison group of 181 persons who had received 1 or 2 doses . RESULTS Only 1 ( 0.55 % ) of 179 persons who had received > or = 3 PPV doses and 4 ( 2.76 % ) of 181 persons in the comparison group had a medically attended adverse event , and no severe adverse events were recorded . CONCLUSION We found no difference in the risk of medically attended adverse events following > or = 3 doses of PPV , compared with 1 or 2 doses BACKGROUND Unlike free polysaccharide vaccines , pneumococcal polysaccharide conjugate vaccines ( PCVs ) induce a T cell-dependent immune response and have the potential to provide an extended duration of protection with repeated vaccinations . METHODS This was an extension of a previous study in pneumococcal  vaccine-naïve adults 
    Output:
    