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"Carrier State - immunology"
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Comparative Immunogenicity and Efficacy of 13-Valent and 7-Valent Pneumococcal Conjugate Vaccines in Reducing Nasopharyngeal Colonization: A Randomized Double-Blind Trial
by
Dagan, Ron
,
Juergens, Christine
,
Greenberg, David
in
Antibodies, Bacterial - blood
,
ARTICLES AND COMMENTARIES
,
Bacterial diseases
2013
Background. The 13-valent pneumococcal conjugate vaccine (PCV13) was licensed to replace the 7-valent pneumococcal conjugate vaccine (PCV7) based on serological noninferiority criteria. To date no randomized PCV13 pediatric trial has included clinical endpoints. Methods. This randomized double-blind trial compared the impact of PCV13 versus PCV7 on nasopharyngeal (NP) colonization and immunogenicity. Healthy infants were randomized (1:1) to receive PCV7 or PCV13 at ages 2, 4, 6, and 12 months; NP swabs were collected at 2, 4, 6, 7, 12, 13, 18, and 24 months, and blood was drawn at 7 and 13 months. Rates of NP acquisition and prevalence, and serotype-specific immunoglobulin G (IgG) concentrations were assessed. Results. The per protocol analysis population included 881 PCV13 and 873 PCV7 recipients. PCV13 significantly reduced NP acquisition of the additional PCV13 serotypes 1, 6A, 7F, and 19A; the cross-reacting serotype 6C; and the common PCV7 serotype 19F. For serotype 3, and the other PCV7 serotypes, there were no significant differences between the vaccine groups. There were too few serotype 5 events to draw inference. The impact on prevalence at predefined time points was similar to that observed with NP acquisition. PCV13 elicited significantly higher IgG responses for PCV13 additional serotypes and serotype 19F, and similar or lower responses for 6/7 PCV7 serotypes. Conclusions. PCV13 resulted in lower acquisition and prevalence of NP colonization than PCV7 did for 4 additional PCV13 serotypes, and serotypes 6C and 19F. It was comparable with PCV7 for all other common serotypes. These findings predict vaccine effectiveness through both direct and indirect protection. Clinical Trials Registration. NCT00508742.
Journal Article
Effect of Pneumococcal Conjugate Vaccine on Nasopharyngeal Colonization among Immunized and Unimmunized Children in a Community-Randomized Trial
by
Santosham, Mathuram
,
Becenti, Jocelyn
,
Reid, Raymond
in
Applied microbiology
,
Bacteria
,
Bacteriology
2007
Background.Pneumococcal conjugate vaccines (PCVs) prevent vaccine serotype (VT) invasive disease; nonvaccine serotype (NVT) disease increases modestly. The impact of PCV on nasopharyngeal (NP) colonization is essential to understanding disease effects. Methods.We conducted a community-randomized controlled trial with catch-up vaccination through age 2 years investigating the effect of 7-valent PCV (PnCRM7) on NP colonization among American Indian infants and their unvaccinated contacts. Infants receiving blinded vaccine at 2, 4, 6, and 12–15 months of age had NP cultures obtained at age 7, 12, and 18 months. Serotype-specific colonization was detected by immunoblot. Results.We enrolled 566 vaccinated and 286 unvaccinated children from 511 households and collected 5157 specimens, of which 3525 (68.4%) had pneumococcus. PnCRM7 vaccinees were less likely to be colonized with VT (odds ratio [OR], 0.40 [95% confidence interval {CI}, 0.23–0.67]) but were more likely to be colonized with NVT pneumococci (OR, 1.67 [95% CI, 1.02–2.78]). PnCRM7 vaccinees were less densely colonized with VT strains than control vaccinees (OR, 0.61 [95% CI, 0.38–0.99]). Day care–attending unvaccinated children in PnCRM7 communities were less likely to have VT colonization than those in control communities (OR, 0.27 [95% CI, 0.07–1.07]). Conclusions.PnCRM7 reduces the risk of VT acquisition and colonization density but increases the risk of NVT acquisition among vaccinees and their household contacts.
Journal Article
Pneumococcal Carriage in Children under Five Years in Uganda-Will Present Pneumococcal Conjugate Vaccines Be Appropriate?
by
Kalyango, Joan
,
Bwanga, Freddie
,
Källander, Karin
in
Antibiotics
,
Biology and Life Sciences
,
Carrier State - immunology
2016
Pneumonia is the major cause of death in children globally, with more than 900,000 deaths annually in children under five years of age. Streptococcus pneumoniae causes most deaths, most often in the form of community acquired pneumonia. Pneumococcal conjugate vaccines (PCVs) are currently being implemented in many low-income countries. PCVs decrease vaccine-type pneumococcal carriage, a prerequisite for invasive pneumococcal disease, and thereby affects pneumococcal disease and transmission. In Uganda, PCV was launched in 2014, but baseline data is lacking for pneumococcal serotypes in carriage.
To study pneumococcal nasopharyngeal carriage and serotype distribution in children under 5 years of age prior to PCV introduction in Uganda.
Three cross-sectional pneumococcal carriage surveys were conducted in 2008, 2009 and 2011, comprising respectively 150, 587 and 1024 randomly selected children aged less than five years from the Iganga/Mayuge Health and Demographic Surveillance Site. The caretakers were interviewed about illness history of the child and 1723 nasopharyngeal specimens were collected. From these, 927 isolates of S. pneumoniae were serotyped.
Overall, the carriage rate of S. pneumoniae was 56% (957/1723). Pneumococcal carriage was associated with illness on the day of the interview (OR = 1.50, p = 0.04). The most common pneumococcal serotypes were in descending order 19F (16%), 23F (9%), 6A (8%), 29 (7%) and 6B (7%). One percent of the strains were non-typeable. The potential serotype coverage rate for PCV10 was 42% and 54% for PCV13.
About half of circulating pneumococcal serotypes in carriage in the Ugandan under-five population studied was covered by available PCVs.
Journal Article
Effect of vaccination with pneumococcal capsular polysaccharides conjugated to Haemophilus influenzae-derived protein D on nasopharyngeal carriage of Streptococcus pneumoniae and H. influenzae in children under 2 years of age
by
Prymula, Roman
,
Pascal, Thierry
,
Schuerman, Lode
in
Acute otitis media
,
Allergy and Immunology
,
Bacterial Proteins - immunology
2009
Following primary and booster vaccination with an 11-valent pneumococcall protein D conjugate vaccine there was a 42.8% (95% CI: −16.7 to 71.9, ns) reduction in the carriage of
Streptococcus pneumoniae vaccine serotypes and a 42.6% (95% CI: 1.3–66.6) reduction in the carriage of
Haemophilus influenzae identified by standard microbiological techniques. When PCR and immunoblot assays were used to further improve specificity of non-typeable
H. influenzae strain identification, carriage of
H. influenzae was still reduced with 38.6% (95% CI: −6.3 to 64.6, ns). Reduction of acute otitis media (AOM) episodes preceded the impact on carriage. These data provide further support of the functional role of the protein D immunity.
Journal Article
PneuMum: Impact from a randomised controlled trial of maternal 23-valent pneumococcal polysaccharide vaccination on middle ear disease amongst Indigenous infants, Northern Territory, Australia
by
Binks, Michael J.
,
Morris, Peter S.
,
Nelson, Jane
in
23-valent pneumococcal polysaccharide vaccine
,
Adolescent
,
Adult
2015
•We achieved our intended sample size of 210 participants.•Rates of ear disease (71%) and 23vPPV-type carriage (26%) were lower than expected.•We were unable to show maternal 23vPPV efficacy against infant ear disease or 23vPPV-type carriage.•23vPPV in pregnancy halved infant ear disease concurrent with 23vPPV-type carriage.•23vPPV in pregnancy may complement childhood pneumococcal vaccination programs.
We assessed maternal 23-valent pneumococcal polysaccharide (23vPPV) vaccine efficacy (VE) against middle ear disease and pneumococcal carriage amongst Australian Indigenous infants.
In an open label, allocation concealed, outcome-assessor blinded, community stratified, randomised controlled trial, healthy pregnant Indigenous women aged 17–39 years in the Northern Territory of Australia received the 23vPPV (1:1:1) at: 30–36 weeks gestation, birth, or were unvaccinated (ClinicalTrials.gov NCT00714064). Co-primary outcomes were the point prevalences of infant middle ear disease and 23vPPV-type carriage at age 7 months.
The consent rate was 50% (313/632). Among 227 eligible participants randomised, retention rates were 86% (66/77) controls; 89% (67/75) pregnancy vaccinees; 88% (66/75) birth vaccinees. At infant age 7 months, ear disease prevalence was: 71% (47/66) controls, 63% (42/67) pregnancy vaccinees, 76% (50/66) birth vaccinees; and 23vPPV-type carriage was: 26% (17/66) controls, 18% (12/67) pregnancy vaccinees, 18% (12/66) birth vaccinees. For pregnancy vaccinees, VE was 12% (95% CI −12% to 31%) against infant ear disease and 30% (95% CI −34% to 64%) against 23vPPV-type carriage. In a post-hoc analysis, VE against infant ear disease concurrent with carriage of 23vPPV or related types was 51% (95% CI −2% to 76%). There were no serious adverse effects following receipt of the 23vPPV in pregnancy or at birth.
In a high risk population, our study was unable to demonstrate efficacy of 23vPPV in pregnancy against the co-primary outcomes of either all-cause infant ear disease or 23vPPV-type nasopharyngeal carriage at age 7 months. Efficacy against ear disease concurrent with carriage of vaccine-related serotypes (a more specific outcome) suggests 23vPPV in pregnancy may complement childhood pneumococcal vaccination programs.
Journal Article
PCV13-vaccinated children still carrying PCV13 additional serotypes show similar carriage density to a control group of PCV7-vaccinated children
by
Dagan, Ron
,
Juergens, Christine
,
Trammel, James
in
Allergy and Immunology
,
Arabs
,
Bacterial Load - immunology
2017
•Limited evidence suggests that PCVs impact vaccine-type carriage density.•This double-blind PCV study suggests no impact on vaccine-type carriage density.•PCV13 may affect carriage by reducing carrier number but not vaccine-type density.•Carriage density may not impact herd effects.
In addition to reducing vaccine-type nasopharyngeal carriage rates, pneumococcal conjugate vaccines (PCVs) may decrease carriage density in vaccinated individuals still carrying vaccine serotypes. However, reduction of carriage density has not been systematically studied. This study compared the effect of PCV13 versus PCV7 on carriage density of the serotypes in PCV13 that are not included in PCV7.
This randomized, double-blind study was conducted in southern Israel and included Jewish and Bedouin subjects. Per protocol, 881 and 873 infants received PCV13 and PCV7, respectively, at ages 2, 4, 6, and 12months. Nasopharyngeal cultures at ages 7, 12, 13, 18, and 24months were plated using the 4-quadrant semiquantitative method and graded 0 (negative) to 4 (growth in all plate quadrants). In this post hoc analysis, the least squares means of cumulative colonization densities per serotype and serotype combination of the total population and each ethnic subpopulation in each vaccine group were calculated, and differences between vaccine groups derived from a linear model.
PCV13-vaccinated children still carrying the 6 additional PCV13 serotypes unique to PCV13 showed no significant differences in carriage density compared with the PCV7-vaccinated control group. No differences in carriage density were shown between Jewish and Bedouin subpopulations despite higher carriage rates among Bedouin subjects.
Although PCV13 vaccination reduces vaccine-type carriage compared with PCV7 vaccination by reducing nasopharyngeal acquisition of the additional PCV13 serotypes as previously reported, the current study lacks evidence of a decrease in carriage density of these serotypes when acquired in vaccinated children. Despite the lack of effect on carriage density observed, surveillance data suggest a dramatic decrease in disease rates after PCV implementation. Thus, the current analysis suggests that PCV’s impact on carriage density has minimal or no impact on vaccine success. (www.ClinicalTrials.gov: NCT00508742)
Journal Article
The effect of an alternative reduced-dose infant schedule and a second year catch-up schedule with 7-valent pneumococcal conjugate vaccine on pneumococcal carriage: A randomized controlled trial
by
Dagan, Ron
,
Givon-Lavi, Noga
,
Porat, Nurith
in
Allergy and Immunology
,
Alternative schedule
,
Antibodies, Bacterial - blood
2012
► The extent of PCV effect on carriage determines indirect protection. ► PCV7 is licensed as a 4-dose regimen (3+1), but shorter regimens are often adopted. ► We show that a reduced schedule (2+1) results in nasopharyngeal carriage reduction. ► 3+1 and 2+1 schedules showed differences in PCV7-type carriage corrected by booster. ► We found that 2-dose 2nd-year catch-up campaigns may enhance carriage reduction.
The 7-valent pneumococcal conjugate vaccine (PCV7) was initially licensed for use as 3 infant doses and a booster (3+1). However, 2 infant doses plus a booster schedules only (2+1) are widely used. We compared the effect of these two schedules on pneumococcal carriage in young children. We also assessed the effect of a 2-dose schedule in the second year (“catch-up” schedule; 0+2).
Subjects (n=733) were randomized to the 2+1 (4, 6, 12m), 3+1 (2, 4, 6, 12m) or 0+2 (12, 18m) schedules. Blood samples for serotype-specific IgG (SSIgG) determination were obtained at 2, 7, 13, 19 months, and nasopharyngeal+oropharyngeal pneumococcal cultures were obtained at 2, 4, 6, 7, 12, 13, 18, 19, 24, 30 months.
After primary infant PCV7 series, SSIgG was significantly lower for four out of seven serotypes in children receiving 2 doses compared to 3 doses, particularly for serotypes 6B and 23F. This was associated with a higher acquisition and prevalence rates of vaccine serotype carriage in the 2-dose group, particularly serotypes 6A and 6B. After the booster dose at 12 months of age, most differences were not significant anymore. A single PCV7 dose at age 12 months in previously unvaccinated subjects (“catch up” schedule) resulted in poor SSIgG concentrations for three out of seven serotypes, resulting in higher acquisition and prevalence rates of vaccine serotypes (grouped) compared to infants receiving a booster dose at 12 months (2+1 and 3+1 groups). Similarly, serotypes 6B and 6A also showed significantly higher carriage rates after a single dose at 12 months. After the second catch-up dose at 18 months, the rates were similar to those in the 2+1 or 3+1 schedules, except for serotype 6A.
Three infant doses seem to better protect against PCV7-serotype acquisition and carriage than two. However, after booster, most of these differences disappear. A 2-dose second year catch-up campaign may enhance the reduction of PCV7-serotype spread in the community.
Journal Article
Immunogenicity and Efficacy of Pneumococcal Conjugate Vaccine (Prevenar13®) in Preventing Acquisition of Carriage of Pneumococcal Vaccine Serotypes in Tanzanian Children With HIV/AIDS
by
Booy, Robert
,
Kisinza, William
,
Bwana, Veneranda M.
in
Acquired immune deficiency syndrome
,
Acquired Immunodeficiency Syndrome - complications
,
Adolescent
2021
In every year, up to one million children die due to pneumococcal disease. Children infected with Human Immunodeficiency Virus (HIV) are mostly affected, as they appear to have higher rates of pneumococcal carriage and invasive disease. Successful immunity is dependent on mounting a sufficient immune response to the vaccine. We conducted a double blinded crossover randomised controlled trial to determine the serum antibody response (≥4-fold and geometric mean concentration) to pneumococcal vaccine (PCV13) serotypes at 3 months after second vaccination. We also determined the number and proportion of children carrying new (not present at baseline) vaccine serotypes of S. pneumoniae isolated from nasopharynx at 6 months post initial vaccination in recipients of Prevenar13 ® compared with those given Haemophilus influenzae -type b (Hib) vaccine (control). The study was conducted at St Augustine's also known as Teule Hospital in Muheza, Tanga Tanzania. 225 HIV infected children aged 1-14 years were enrolled from Jan 2013 to Nov 2013 and randomised to Prevenar13 ® or Hib vaccines each given at baseline and 2-3 months later. Nasopharyngeal and serum samples were collected at baseline and 4-6 months later. Serotyping was done by Quellung Reaction using Staten antisera. Serum antibodies were ELISA quantified. The study revealed a non-significant reduction in the acquisition of new vaccine serotypes of S. pneumoniae in the recipients of PCV13 by nearly a third compared to those who received Hib vaccine. The vaccine efficacy was 30.5% (95% confidence interval [CI] –6.4-54.6%, P = 0.100)]. The antibody response was not enough to induce a 4-fold rise in GMC in 7 of the 13 vaccine serotypes. When combining the effects of preventing new acquisition and clearing existing vaccine type carriage, the overall efficacy was 31.5% (95% CI 1.5-52.4%, P = 0.045). In the PCV13 group, the proportion of participants carrying vaccine serotype was significantly lower after 2 doses of PCV13 (30%; 32/107), compared with the baseline proportion (48%; 51/107). The introduction of PCV13 targeting HIV-positive children in a setting similar to Tanzania is likely to be associated with appreciable decrease in the acquisition and carriage of pneumococci, which is an important marker of the likely effect of the vaccine on pneumococcal disease.
Journal Article
Indirect Effect of 7-Valent Pneumococcal Conjugate Vaccine on Pneumococcal Carriage in Newborns in Rural Gambia: A Randomised Controlled Trial
2012
Gambian infants frequently acquire Streptococcus pneumoniae soon after birth. We investigated the indirect effect of 7-valent pneumococcal conjugate vaccine (PCV-7) on pneumococcal acquisition in newborn Gambian babies.
Twenty-one villages were randomised to receive PCV-7 to all subjects (11 vaccinated villages) or to infants aged 2-30 months (10 control villages). Other control villagers received Meningococcal C conjugate vaccine. From 328 babies born during the trial, nasopharyngeal swabs were collected after birth, then weekly until 8 weeks of age when they received their first dose of PCV-7. Pneumococcal carriage and acquisition rates were compared between the study arms and with a baseline study.
57.4% of 2245 swabs were positive for S. pneumoniae. Overall carriage was similar in both arms. In vaccinated villages fewer infants carried pneumococci of vaccine serotypes (VT) (16.9% [31/184] vs. 37.5% [54/144], p<0.001) and more carried pneumococci of non-vaccine serotypes (NVT) (80.9% [149/184] vs. 75.7% [109/144], p = 0.246). Infants from vaccinated villages had a significantly lower acquisition rate of VT (HR 0.39 [0.26-0.58], p<0.001) and increased acquisition of NVT (HR 1.16 [0.87-1.56], p = 0.312). VT carriage (51.6% vs. 37.5%, p = 031 in control and 46.1% vs. 16.8%, p<0.001 in vaccinated villages) and acquisition rates (HR 0.68 [0.50-0.92], p = 0.013 in control villages and HR 0.31 [0.19-0.50], p<.001 in vaccinated villages) were significantly lower in both study arms than in the baseline study. NVT carriage (63.2% vs. 75.7%, p = 0.037 in control and 67.2% vs. 75.3%, p = 0.005 in vaccinated villages) and acquisition rates (HR 1.48 [1.06-2.06], p = 0.022) and (HR 1.52 [1.11-2.10], p = 0.010 respectively) were significantly higher.
PCV-7 significantly reduced carriage of VT pneumococci in unvaccinated infants. This indirect effect likely originated from both the child and adult vaccinated populations. Increased carriage of NVT pneumococci needs ongoing monitoring.
ISRCTN Register 51695599.
Journal Article
Combination therapy with anti-HIV-1 antibodies maintains viral suppression
2018
Individuals infected with HIV-1 require lifelong antiretroviral therapy, because interruption of treatment leads to rapid rebound viraemia. Here we report on a phase 1b clinical trial in which a combination of 3BNC117 and 10-1074, two potent monoclonal anti-HIV-1 broadly neutralizing antibodies that target independent sites on the HIV-1 envelope spike, was administered during analytical treatment interruption. Participants received three infusions of 30 mg kg
−1
of each antibody at 0, 3 and 6 weeks. Infusions of the two antibodies were generally well-tolerated. The nine enrolled individuals with antibody-sensitive latent viral reservoirs maintained suppression for between 15 and more than 30 weeks (median of 21 weeks), and none developed viruses that were resistant to both antibodies. We conclude that the combination of the anti-HIV-1 monoclonal antibodies 3BNC117 and 10-1074 can maintain long-term suppression in the absence of antiretroviral therapy in individuals with antibody-sensitive viral reservoirs.
Combination therapy with the anti-HIV-1 monoclonal antibodies 3BNC117 and 10-1074 maintains long-term suppression in the absence of antiretroviral therapy in individuals with antibody-sensitive viral reservoirs.
Journal Article