Evaluation of Recombinant Live-Attenuated Respiratory Syncytial Virus (RSV) Vaccines RSV/ΔNS2/Δ1313/I1314L and RSV/276 in RSV-Seronegative Children.

BACKGROUND: This United States-based study compared 2 candidate vaccines: RSV/ΔNS2/Δ1313/I1314L, attenuated by NS2 gene-deletion and temperature-sensitivity mutation in the polymerase gene; and RSV/276, attenuated by M2-2 deletion. METHODS: RSV-seronegative children aged 6-24 months received RSV/ΔNS2/Δ1313/I1314L (106 plaque-forming units [PFU]), RSV/276 (105 PFU), or placebo intranasally. Participants were monitored for vaccine shedding, reactogenicity, and RSV serum antibodies, and followed over the subsequent RSV season. RESULTS: Enrollment occurred September 2017 to October 2019. During 28 days postinoculation, upper respiratory illness and/or fever occurred in 64% of RSV/ΔNS2/Δ1313/I1314L, 84% of RSV/276, and 58% of placebo recipients. Symptoms were generally mild. Cough was more common in RSV/276 recipients than RSV/ΔNS2/Δ1313/I1314L (48% vs 12%; P = .012) or placebo recipients (17%; P = .084). There were no lower respiratory illness or serious adverse events. Eighty-eight and 96% of RSV/ΔNS2/Δ1313/I1314L and RSV/276 recipients were infected with vaccine (shed vaccine and/or had ≥4-fold rises in RSV antibodies). Serum RSV-neutralizing titers and anti-RSV F IgG titers increased ≥4-fold in 60% and 92% of RSV/ΔNS2/Δ1313/I1314L and RSV/276 vaccinees, respectively. Exposure to community RSV during the subsequent winter was associated with strong anamnestic RSV-antibody responses. CONCLUSIONS: Both vaccines had excellent infectivity and were well tolerated. RSV/276 induced an excess of mild cough. Both vaccines were immunogenic and primed for strong anamnestic responses. CLINICAL TRIALS REGISTRATION: NCT03227029 and NCT03422237.

Effect of Maternal Immunization With 10-Valent Pneumococcus Conjugate Vaccine (PCV-10), 23-Valent Pneumococcus Polysaccharide Vaccine, or Placebo on the Immunogenicity of PCV-10 in Human Immunodeficiency Virus-Exposed Uninfected Infants: A Randomized Clinical Trial.

BACKGROUND: The effect of pneumococcal vaccination of mothers with human immunodeficiency virus (HIV) on infant responses to childhood vaccination has not been studied. We compared the immunogenicity of 10-valent pneumococcus conjugate vaccine (PCV-10) in HIV-exposed uninfected infants born to mothers who received PCV-10, 23-valent pneumococcus polysaccharide vaccine (PPV-23), or placebo during pregnancy. METHODS: Antibody levels against 7 serotypes were measured at birth, before the first and second doses of PCV-10m and after completion of the 2-dose regimen in 347 infants, including 112 born to mothers who received PPV-23, 112 who received PCV-10, and 119 who received placebo during pregnancy. Seroprotection was defined by antibody levels ≥0.35 µg/mL. RESULTS: At birth and at 8 weeks of life, antibody levels were similar in infants born to PCV-10 or PPV-23 recipients and higher than in those born to placebo recipient. After the last dose of PCV-10, infants in the maternal PCV-10 group had significantly lower antibody levels against 5 serotypes than those in the maternal PPV-23 group and against 3 serotypes than those in the maternal placebo group, and they did not have higher antibody levels against any serotype. The seroprotection rate against 7 serotypes was 50% in infants in the maternal PCV-10 group, compared with 71% in both of the maternal PPV-23 and placebo groups (P < .001). CONCLUSIONS: Administration of PCV-10 during pregnancy was associated with decreased antibody responses to PCV-10 and seroprotection rates in infants. Considering that PCV-10 and PPV-23 had similar immunogenicity in pregnant women with HIV and that administration of PPV-23 did not affect the immunogenicity of PCV-10 in infants, PPV-23 in pregnancy may be preferred over PCV-10.

Immunogenicity of Conjugated and Polysaccharide Pneumococcal Vaccines Administered During Pregnancy or Postpartum to Women With HIV.

BACKGROUND: Pneumococcal vaccination is recommended in people with HIV, prioritizing PCV. We compared the immunogenicity of PCV-10 and PPV-23 administered antepartum or postpartum. METHODS: This double-blind study randomized 346 pregnant women with HIV on antiretrovirals to PCV-10, PPV-23, or placebo at 14-34 weeks gestational age. Women who received placebo antepartum were randomized at 24 weeks postpartum to PCV-10 or PPV-23. Antibodies against 7 serotypes common to both vaccines and 1 serotype only in PPV-23 were measured by ELISA/chemiluminescence; B- and T-cell responses to serotype 1 by FLUOROSPOT; and plasma cytokines/chemokines by chemiluminescence. RESULTS: Antibody responses were higher after postpartum versus antepartum vaccination. PCV-10 generated lower antibody levels than PPV-23 against 4 and higher against 1 of 7 common serotypes. Additional factors associated with high postvaccination antibody concentrations were high prevaccination antibody concentrations and CD4+ cells; low CD8+ cells and plasma HIV RNA; and several plasma cytokines/chemokines. Serotype 1 B- and T-cell memory did not increase after vaccination. CONCLUSIONS: Antepartum immunization generated suboptimal antibody responses, suggesting that postpartum booster doses may be beneficial and warrant further studies. Considering that PCV-10 and PPV-23 had similar immunogenicity, but PPV-23 covered more serotypes, use of PPV-23 may be prioritized in women with HIV on antiretroviral therapy. CLINICAL TRAILS REGISTRATION: NCT02717494.

Safety, Tolerability, and Pharmacokinetics of a Long-Acting Broadly Neutralizing Human Immunodeficiency Virus Type 1 (HIV-1) Monoclonal Antibody VRC01LS in HIV-1-Exposed Newborn Infants.

BACKGROUND: Perinatal human immunodeficiency virus type 1 (HIV-1) continues to occur due to barriers to effective antiretroviral prevention that might be mitigated by long-acting broadly neutralizing monoclonal antibodies (bNAbs). METHODS: An extended half-life bNAb, VRC01LS, was administered subcutaneously at 80 mg/dose after birth to HIV-1-exposed, nonbreastfed (cohort 1, n = 10) and breastfed (cohort 2, n = 11) infants. Cohort 2 received a second dose (100 mg) at 12 weeks. All received antiretroviral prophylaxis. VRC01LS levels were compared to VRC01 levels determined in a prior cohort. RESULTS: Local reactions (all grade ≤2) occurred in 67% and 20% after dose 1 and dose 2, respectively. The weight-banded dose (mean 28.8 mg/kg) of VRC01LS administered subcutaneously achieved a mean (standard deviation) plasma level of 222.3 (71.6) µg/mL by 24 hours and 44.0 (11.6) µg/mL at week 12, prior to dose 2. The preestablished target of ≥50 µg/mL was attained in 95% and 32% at weeks 8 and 12, respectively. The terminal half-life was 37-41 days. VRC01LS level after 1 dose was significantly greater (P <.002) than after a VRC01 dose (20 mg/kg). No infants acquired HIV-1. CONCLUSIONS: VRC01LS was well tolerated with pharmacokinetics that support further studies of more potent long-acting bNAbs as adjunct treatment with antiretrovirals to prevent infant HIV-1 transmission.

Safety, immunogenicity, and transplacental antibody transport of conjugated and polysaccharide pneumococcal vaccines administered to pregnant women with HIV: a multicentre randomised controlled trial.

BACKGROUND: Pneumococcus remains an important cause of morbidity in pregnant women with HIV and their infants. We compared the safety and immunogenicity of PCV-10 and PPV-23 with placebo administered in pregnancy. METHODS: This double-blind, multicentre, randomised controlled trial was done at eight outpatient clinics in Brazil. Eligible participants were adult women with HIV who were pregnant at a gestational age between 14 weeks and less than 34 weeks and who were taking antiretroviral therapy at study entry. Participants were randomly assigned (1:1:1) to receive either PCV-10, PPV-23, or placebo. Participants and study teams were unaware of treatment allocation. Antibodies against seven vaccine serotypes in PCV-10 and PPV-23 were measured by ELISA. The primary outcomes were maternal and infant safety assessed by the frequency of adverse events of grade 3 or higher; maternal seroresponse (defined as ≥2-fold increase in antibodies from baseline to 28 days after immunisation) against five or more serotypes; and infant seroprotection (defined as anti-pneumococcus antibody concentration of ≥0·35 µg/mL) against five or more serotypes at 8 weeks of life. The study was powered to detect differences of 20% or higher in the primary immunological outcomes between treatment groups. This trial is registered with ClinicalTrials.gov, NCT02717494. FINDINGS: Between April 1, 2016, and Nov 30, 2017, we enrolled 347 pregnant women with HIV, of whom 116 were randomly assigned to the PCV-10 group, 115 to the PPV-23 group, and 116 to the placebo group. One participant in the PCV-10 group did not receive the vaccine and was excluded from subsequent analyses. The frequency of adverse events of grade 3 or higher during the first 4 weeks was similar in the vaccine and placebo groups (3% [90% CI 1-7] for the PCV-10 group, 2% [0-5] for the PPV-23 group, and 3% [1-8] for the placebo group). However, injection site and systemic grade 2 adverse reactions were reported more frequently during the first 4 weeks in the vaccine groups than in the placebo group (14% [9-20] for the PCV-10 group, 7% [4-12] for the PPV-23 group, and 3% [1-7] for the placebo group). The frequency of grade 3 or higher adverse effects was similar across maternal treatment groups (20% [14-27] for the PCV-10 group, 21% [14-28] for the PPV-23 group, and 20% [14-27] for the placebo group). Seroresponses against five or more serotypes were present in 74 (65%) of 114 women in the PCV-10 group, 72 (65%) of 110 women in the PPV-23 group, and none of the 113 women in the placebo group at 4 weeks post vaccination (p<0·0001 for PPV-23 group vs placebo and PCV-10 group vs placebo). Seroresponse differences of 20% or higher in vaccine compared with placebo recipients persisted up to 24 weeks post partum. At birth, 76 (67%) of 113 infants in the PCV-10 group, 62 (57%) of 109 infants in the PPV-23 group, and 19 (17%) of 115 infants in the placebo group had seroprotection against five or more serotypes (p<0·0001 for PPV-23 vs placebo and PCV-10 vs placebo). At 8 weeks, the outcome was met by 20 (19%) of 108 infants in the PCV-10 group, 24 (23%) of 104 infants in the PPV-23 group, and one (1%) of 109 infants in the placebo group (p<0·0001). Although a difference of 20% or higher compared with placebo was observed only in the infants who received PPV-23 at 8 weeks of life, the difference between the two vaccine groups was not appreciable. INTERPRETATION: PCV-10 and PPV-23 were equally safe and immunogenic in pregnant women with HIV and conferred similar levels of seroprotection to their infants. In areas in which childhood PCV administration decreased the circulation of PCV serotypes, PPV-23 administration to pregnant women with HIV might be more advantageous than PCV by virtue of including a broader range of serotypes. FUNDING: Eunice Kennedy Shriver National Institute of Child Health and Human Development. TRANSLATION: For the Portuguese translation of the abstract see Supplementary Materials section.

Live-attenuated Vaccines Prevent Respiratory Syncytial Virus-associated Illness in Young Children.

Rationale: Active immunization is needed to protect infants and young children against respiratory syncytial virus (RSV). Rationally designed live-attenuated RSV vaccines are in clinical development.Objectives: Develop preliminary estimates of vaccine efficacy, assess durability of antibody responses to vaccination and "booster" responses after natural RSV infection, and determine sample sizes needed for more precise estimates of vaccine efficacy.Methods: We analyzed data from seven phase 1 trials of live-attenuated RSV vaccines in 6- to 24-month-old children (n = 239).Measurements and Main Results: The five vaccine regimens that induced neutralizing antibody responses in ≥80% of vaccinees (defined post hoc as "more promising") protected against RSV-associated medically attended acute respiratory illness (RSV-MAARI) and medically attended acute lower respiratory illness (RSV-MAALRI) and primed for potent anamnestic responses upon natural exposure to wild-type RSV. Among recipients of "more promising" RSV vaccines, efficacy against RSV-MAARI was 67% (95% confidence interval [CI], 24 to 85; P = 0.008) and against RSV-MAALRI was 88% (95% CI, -9 to 99; P = 0.04). A greater than or equal to fourfold increase in RSV serum neutralizing antibody following vaccination was strongly associated with protection against RSV-MAARI (odds ratio, 0.26; 95% CI, 0.09 to 0.75; P = 0.014) and RSV-MAALRI; no child with a greater than or equal to fourfold increase developed RSV-MAALRI. Rates of RSV-MAARI and RSV-MAALRI in placebo recipients were 21% and 7%, respectively. Given these rates, a study of 540 RSV-naive children would have 90% power to demonstrate ≥55% efficacy against RSV-MAARI and ≥80% efficacy against RSV-MAALRI; if rates were 10% and 3%, a study of 1,300 RSV-naive children would be needed.Conclusions: Rapid development of a live-attenuated RSV vaccine could contribute substantially to reducing the global burden of RSV disease.

Live-Attenuated Respiratory Syncytial Virus Vaccine With M2-2 Deletion and With Small Hydrophobic Noncoding Region Is Highly Immunogenic in Children.

BACKGROUND: Respiratory syncytial virus (RSV) is the leading viral cause of severe pediatric respiratory illness, and vaccines are needed. Live RSV vaccine D46/NS2/N/ΔM2-2-HindIII, attenuated by deletion of the RSV RNA regulatory protein M2-2, is based on previous candidate LID/ΔM2-2 but incorporates prominent differences from MEDI/ΔM2-2, which was more restricted in replication in phase 1. METHODS: RSV-seronegative children aged 6-24 months received 1 intranasal dose (105 plaque-forming units [PFUs] of D46/NS2/N/ΔM2-2-HindIII [n = 21] or placebo [n = 11]) and were monitored for vaccine shedding, reactogenicity, RSV-antibody responses and RSV-associated medically attended acute respiratory illness (RSV-MAARI) and antibody responses during the following RSV season. RESULTS: All 21 vaccinees were infected with vaccine; 20 (95%) shed vaccine (median peak titer, 3.5 log10 PFUs/mL with immunoplaque assay and 6.1 log10 copies/mL with polymerase chain reaction). Serum RSV-neutralizing antibodies and anti-RSV fusion immunoglobulin G increased ≥4-fold in 95% and 100% of vaccines, respectively. Mild upper respiratory tract symptoms and/or fever occurred in vaccinees (76%) and placebo recipients (18%). Over the RSV season, RSV-MAARI occurred in 2 vaccinees and 4 placebo recipients. Three vaccinees had ≥4-fold increases in serum RSV-neutralizing antibody titers after the RSV season without RSV-MAARI. CONCLUSIONS: D46/NS2/N/ΔM2-2-HindIII had excellent infectivity and immunogenicity and primed vaccine recipients for anamnestic responses, encouraging further evaluation of this attenuation strategy. CLINICAL TRIALS REGISTRATION: NCT03102034 and NCT03099291.

Live Respiratory Syncytial Virus Attenuated by M2-2 Deletion and Stabilized Temperature Sensitivity Mutation 1030s Is a Promising Vaccine Candidate in Children.

BACKGROUND: The safety and immunogenicity of live respiratory syncytial virus (RSV) candidate vaccine, LID/ΔM2-2/1030s, with deletion of RSV ribonucleic acid synthesis regulatory protein M2-2 and genetically stabilized temperature-sensitivity mutation 1030s in the RSV polymerase protein was evaluated in RSV-seronegative children. METHODS: Respiratory syncytial virus-seronegative children ages 6-24 months received 1 intranasal dose of 105 plaque-forming units (PFU) of LID/ΔM2-2/1030s (n = 21) or placebo (n = 11). The RSV serum antibodies, vaccine shedding, and reactogenicity were assessed. During the following RSV season, medically attended acute respiratory illness (MAARI) and pre- and postsurveillance serum antibody titers were monitored. RESULTS: Eighty-five percent of vaccinees shed LID/ΔM2-2/1030s vaccine (median peak nasal wash titers: 3.1 log10 PFU/mL by immunoplaque assay; 5.1 log10 copies/mL by reverse-transcription quantitative polymerase chain reaction) and had ≥4-fold rise in serum-neutralizing antibodies. Respiratory symptoms and fever were common (60% vaccinees and 27% placebo recipients). One vaccinee had grade 2 wheezing with rhinovirus but without concurrent LID/ΔM2-2/1030s shedding. Five of 19 vaccinees had ≥4-fold increases in antibody titers postsurveillance without RSV-MAARI, indicating anamnestic responses without significant illness after infection with community-acquired RSV. CONCLUSIONS: LID/ΔM2-2/1030s had excellent infectivity without evidence of genetic instability, induced durable immunity, and primed for anamnestic antibody responses, making it an attractive candidate for further evaluation.

Safety, Tolerability, and Pharmacokinetics of the Broadly Neutralizing Human Immunodeficiency Virus (HIV)-1 Monoclonal Antibody VRC01 in HIV-Exposed Newborn Infants.

BACKGROUND: Although mother-to-child human immunodeficiency virus (HIV) transmission has dramatically decreased with maternal antiretroviral therapy, breast milk transmission accounts for most of the 180 000 new infant HIV infections annually. Broadly neutralizing antibodies (bNAb) may further reduce transmission. METHODS: A Phase 1 safety and pharmacokinetic study was conducted: a single subcutaneous (SC) dose of 20 or 40 mg/kg (Dose Groups 1 and 2, respectively) of the bNAb VRC01 was administered to HIV-exposed infants soon after birth. Breastfeeding infants (Dose Group 3) received 40 mg/kg SC VRC01 after birth and then 20 mg/kg/dose SC monthly. All infants received appropriate antiretroviral prophylaxis. RESULTS: Forty infants were enrolled (21 in the United States, 19 in Africa). Subcutaneous VRC01 was safe and well tolerated with only mild-to-moderate local reactions, primarily erythema, which rapidly resolved. For multiple-dose infants, local reactions decreased with subsequent injections. VRC01 was rapidly absorbed after administration, with peak concentrations 1-6 days postdose. The 40 mg/kg dose resulted in 13 of 14 infants achieving the serum 50 micrograms (mcg)/mL target at day 28. Dose Group 3 infants maintained concentrations greater than 50 mcg/mL throughout breastfeeding. CONCLUSIONS: Subcutaneous VRC01 as single or multiple doses is safe and well tolerated in very young infants and is suitable for further study to prevent HIV transmission in infants.

Live-Attenuated Respiratory Syncytial Virus Vaccine With Deletion of RNA Synthesis Regulatory Protein M2-2 and Cold Passage Mutations Is Overattenuated.

BACKGROUND: The live respiratory syncytial virus (RSV) candidate vaccine LIDcpΔM2-2 is attenuated through deletion of M2-2 and 5 cold-passage mutations. METHODS: RSV-seronegative children aged 6-24 months received a single intranasal dose of 105 plaque-forming units (PFU) of LIDcpΔM2-2 or placebo. RSV serum antibodies, vaccine infectivity, and reactogenicity were assessed. RESULTS: Four of 11 (36%) vaccinees shed vaccine virus with median peak titers of 1.6 log10 PFU/mL by quantitative culture and 4.5 log10 copies/mL by polymerase chain reaction; 45% had ≥4-fold rise in serum-neutralizing antibodies. Respiratory symptoms or fever were common in vaccinees (64%) and placebo recipients (6/6, 100%). CONCLUSIONS: RSV LIDcpΔM2-2 is overattenuated. Clinical Trial Numbers. NCT02890381, NCT02948127.

Development and application of a multiplex assay for the simultaneous measurement of antibody responses elicited by common childhood vaccines.

Because vaccine co-administration can affect elicited immune responses, it is important to evaluate new vaccines in the context of pre-existing vaccination schedules. This is particularly necessary for new pediatric vaccines, as the World Health Organization's infant immunization program already schedules several vaccines to be administered during the first months of life. To facilitate the assessment of inter-vaccine interference, we developed a pediatric vaccine multiplex assay (PVMA) to simultaneously measure antibodies against vaccines commonly administered to infants, including hepatitis B, Haemophilus influenzae type B, diphtheria, tetanus, pertussis, rubella, and respiratory syncytial virus (RSV). Comparison of antibody concentrations determined by enzyme-linked immunosorbent assays (ELISAs) and the PVMA demonstrated that the PVMA is highly sensitive, specific, reproducible, and accurate. Moreover, the PVMA requires half the time to assess a cohort compared to ELISAs, and only costs marginally more. Demonstrating the utility of the assay, we employed the PVMA to assess vaccine interference in the setting of a candidate vaccine, using the infant HIV vaccines from the completed Pediatric AIDS Clinical Trials Group (PACTG) protocols 230 and 326 as examples. There was no substantial difference in antibody concentrations between vaccine and placebo recipients, which suggests that HIV vaccination did not disrupt antibody responses elicited by routine pediatric vaccines. Thus, the PVMA is a reliable, high-throughput technique that requires minimal sample volume to measure multiple antibody concentrations concurrently, and is an efficient alternative to ELISAs for the measurement of vaccine-elicited antibody responses in large cohorts.

Live-Attenuated Respiratory Syncytial Virus Vaccine Candidate With Deletion of RNA Synthesis Regulatory Protein M2-2 is Highly Immunogenic in Children.

Background: Live respiratory syncytial virus (RSV) candidate vaccine LIDΔM2-2 is attenuated by deletion of the RSV RNA regulatory protein M2-2, resulting in upregulated viral gene transcription and antigen expression but reduced RNA replication. Methods: RSV-seronegative children ages 6-24 months received a single intranasal dose of 105 plaque forming units (PFU) of LIDΔM2-2 (n = 20) or placebo (n = 9) (NCT02237209, NCT02040831). RSV serum antibodies, vaccine infectivity, and reactogenicity were assessed. During the following RSV season, participants were monitored for respiratory illness and pre- and post-RSV season serum antibodies. Results: Vaccine virus was shed by 95% of vaccinees (median peak titers of 3.8 log10 PFU/mL by quantitative culture and 6.3 log10 copies/mL by PCR); 90% had ≥4-fold rise in serum neutralizing antibodies. Respiratory symptoms and fever were common in vaccine (95%) and placebo (78%). One vaccinee had grade 2 rhonchi concurrent with vaccine shedding, rhinovirus, and enterovirus. Eight of 19 vaccinees versus 2 of 9 placebo recipients had substantially increased RSV antibody titers after the RSV season without medically attended RSV disease, indicating anamnestic vaccine responses to wild-type RSV without significant illness. Conclusion: LIDΔM2-2 had excellent infectivity and immunogenicity, encouraging further study of vaccine candidates attenuated by M2-2 deletion. Clinical Trials Registration: NCT02237209, NCT02040831.

Live Respiratory Syncytial Virus (RSV) Vaccine Candidate Containing Stabilized Temperature-Sensitivity Mutations Is Highly Attenuated in RSV-Seronegative Infants and Children.

Background: Respiratory syncytial virus (RSV) is the most important viral cause of severe respiratory illness in young children and lacks a vaccine. RSV cold-passage/stabilized 2 (RSVcps2) is a modification of a previously evaluated vaccine candidate in which 2 major attenuating mutations have been stabilized against deattenuation. Methods: RSV-seronegative 6-24-month-old children received an intranasal dose of 105.3 plaque-forming units (PFU) of RSVcps2 (n = 34) or placebo (n = 16) (International Maternal Pediatric Adolescent AIDS Clinical Trials protocol P1114 and companion protocol CIR285). RSV serum neutralizing antibody titers before and 56 days after vaccination, vaccine virus infectivity (defined as vaccine virus shedding detectable in nasal wash and/or a ≥4-fold rise in serum antibodies), reactogenicity, and genetic stability were assessed. During the following RSV transmission season, participants were monitored for respiratory illness, with serum antibody titers measured before and after the season. Results: A total of 85% of vaccinees were infected with RSVcps2 (median peak titer, 0.5 log10 PFU/mL by culture and 2.9 log10 copies/mL by polymerase chain reaction analysis); 77% shed vaccine virus, and 59% developed a ≥4-fold rise in RSV-serum neutralizing antibody titers. Respiratory tract and/or febrile illness occurred at the same rate (50%) in the vaccine and placebo groups. Deattenuation was not detected at either of 2 stabilized mutation sites. Conclusions: RSVcps2 was well tolerated and moderately immunogenic and had increased genetic stability in 6-24-month-old RSV-seronegative children. Clinical Trials Registration: NCT01852266 and NCT01968083.

Heterogeneity of T Cell Responses to Pandemic pH1N1 Monovalent Vaccine in HIV-Infected Pregnant Women.

We investigated the Th1 protective and regulatory T and B cell (Treg and Breg) responses to pH1N1 monovalent influenza vaccine (IIV1) in HIV-infected pregnant women on combination antiretroviral therapy (cART). Peripheral blood mononuclear cells (PBMCs) from 52 study participants were cryopreserved before and after vaccination and analyzed by flow cytometry. pH1N1-specific Th1, Treg, and Breg responses were measured in PBMCs after in vitro stimulation with pH1N1 and control antigen. The cohort analysis did not detect changes in pH1N1-Th1, Treg, or Breg subsets postvaccination. However, individual analyses distinguished subjects who mounted vigorous Th1 responses postvaccination from others who did not. Postvaccination, high pH1N1-Th1 correlated with high pH1N1-Treg and Breg responses, suggesting that low influenza effector responses did not result from excessive vaccine-induced immune regulation. High postvaccination pH1N1-Th1 responses correlated with baseline high PHA- and pH1N1-IFN-γ ELISpot and circulating CD4(+)CD39(+)% and CD8(+)CD39(+)% Treg, with low CD8(+) cell numbers and CD19(+)FOXP3(+)% Breg, but not with CD4(+) cell numbers or HIV viral load. These data highlight the heterogeneity of T cell responses to vaccines in HIV-infected individuals on cART. Predictors of robust Th1 responses to IIV include CD8(+) cell numbers, T cell functionality, and circulating Breg and Treg.

Determinants of vaccine immunogenicity in HIV-infected pregnant women: analysis of B and T cell responses to pandemic H1N1 monovalent vaccine.

Influenza infections have high frequency and morbidity in HIV-infected pregnant women, underscoring the importance of vaccine-conferred protection. To identify the factors that determine vaccine immunogenicity in this group, we characterized the relationship of B- and T-cell responses to pandemic H1N1 (pH1N1) vaccine with HIV-associated immunologic and virologic characteristics. pH1N1 and seasonal-H1N1 (sH1N1) antibodies were measured in 119 HIV-infected pregnant women after two double-strength pH1N1 vaccine doses. pH1N1-IgG and IgA B-cell FluoroSpot, pH1N1- and sH1N1-interferon γ (IFNγ) and granzyme B (GrB) T-cell FluoroSpot, and flow cytometric characterization of B- and T-cell subsets were performed in 57 subjects. pH1N1-antibodies increased after vaccination, but less than previously described in healthy adults. pH1N1-IgG memory B cells (Bmem) increased, IFNγ-effector T-cells (Teff) decreased, and IgA Bmem and GrB Teff did not change. pH1N1-antibodies and Teff were significantly correlated with each other and with sH1N1-HAI and Teff, respectively, before and after vaccination. pH1N1-antibody responses to the vaccine significantly increased with high proportions of CD4+, low CD8+ and low CD8+HLADR+CD38+ activated (Tact) cells. pH1N1-IgG Bmem responses increased with high proportions of CD19+CD27+CD21- activated B cells (Bact), high CD8+CD39+ regulatory T cells (Treg), and low CD19+CD27-CD21- exhausted B cells (Bexhaust). IFNγ-Teff responses increased with low HIV plasma RNA, CD8+HLADR+CD38+ Tact, CD4+FoxP3+ Treg and CD19+IL10+ Breg. In conclusion, pre-existing antibody and Teff responses to sH1N1 were associated with increased responses to pH1N1 vaccination in HIV-infected pregnant women suggesting an important role for heterosubtypic immunologic memory. High CD4+% T cells were associated with increased, whereas high HIV replication, Tact and Bexhaust were associated with decreased vaccine immunogenicity. High Treg increased antibody responses but decreased Teff responses to the vaccine. The proportions of immature and transitional B cells did not affect the responses to vaccine. Increased Bact were associated with high Bmem responses to the vaccine.

Characterization of functional antibody and memory B-cell responses to pH1N1 monovalent vaccine in HIV-infected children and youth.

OBJECTIVES: We investigated immune determinants of antibody responses and B-cell memory to pH1N1 vaccine in HIV-infected children. METHODS: Ninety subjects 4 to <25 years of age received two double doses of pH1N1 vaccine. Serum and cells were frozen at baseline, after each vaccination, and at 28 weeks post-immunization. Hemagglutination inhibition (HAI) titers, avidity indices (AI), B-cell subsets, and pH1N1 IgG and IgA antigen secreting cells (ASC) were measured at baseline and after each vaccination. Neutralizing antibodies and pH1N1-specific Th1, Th2 and Tfh cytokines were measured at baseline and post-dose 1. RESULTS: At entry, 26 (29%) subjects had pH1N1 protective HAI titers (≥1:40). pH1N1-specific HAI, neutralizing titers, AI, IgG ASC, IL-2 and IL-4 increased in response to vaccination (p<0.05), but IgA ASC, IL-5, IL-13, IL-21, IFNγ and B-cell subsets did not change. Subjects with baseline HAI ≥1:40 had significantly greater increases in IgG ASC and AI after immunization compared with those with HAI <1:40. Neutralizing titers and AI after vaccination increased with older age. High pH1N1 HAI responses were associated with increased IgG ASC, IFNγ, IL-2, microneutralizion titers, and AI. Microneutralization titers after vaccination increased with high IgG ASC and IL-2 responses. IgG ASC also increased with high IFNγ responses. CD4% and viral load did not predict the immune responses post-vaccination, but the B-cell distribution did. Notably, vaccine immunogenicity increased with high CD19+CD21+CD27+% resting memory, high CD19+CD10+CD27+% immature activated, low CD19+CD21-CD27-CD20-% tissue-like, low CD19+CD21-CD27-CD20-% transitional and low CD19+CD38+HLADR+% activated B-cell subsets. CONCLUSIONS: HIV-infected children on HAART mount a broad B-cell memory response to pH1N1 vaccine, which was higher for subjects with baseline HAI≥1:40 and increased with age, presumably due to prior exposure to pH1N1 or to other influenza vaccination/infection. The response to the vaccine was dependent on B-cell subset distribution, but not on CD4 counts or viral load. TRIAL REGISTRATION: ClinicalTrials.gov NCT00992836.

Infant HIV type 1 gp120 vaccination elicits robust and durable anti-V1V2 immunoglobulin G responses and only rare envelope-specific immunoglobulin A responses.

BACKGROUND: Infant responses to vaccines can be impeded by maternal antibodies and immune system immaturity. It is therefore unclear whether human immunodeficiency virus type 1 (HIV-1) vaccination would elicit similar responses in adults and infants. METHOD: HIV-1 Env-specific antibody responses were evaluated in 2 completed pediatric vaccine trials. In the Pediatric AIDS Clinical Trials Group (PACTG) 230 protocol, infants were vaccinated with 4 doses of Chiron rgp120 with MF59 (n=48), VaxGen rgp120 with aluminum hydroxide (alum; n=49), or placebo (n=19) between 0 and 20 weeks of age. In PACTG 326, infants received 4 doses of ALVAC-HIV-1/AIDSVAX B/B with alum (n=9) or placebo (n=13) between 0 and 12 weeks of age. RESULTS: By 52 weeks of age, the majority of maternally acquired antibodies had waned and vaccine Env-specific immunoglobulin G (IgG) responses in vaccinees were higher than in placebo recipients. Chiron vaccine recipients had higher and more-durable IgG responses than VaxGen vaccine recipients or ALVAC/AIDSVAX vaccinees, with vaccine-elicited IgG responses still detectable in 56% of recipients at 2 years of age. Remarkably, at peak immunogenicity, the concentration of anti-V1V2 IgG, a response associated with a reduced risk of HIV-1 acquisition in the RV144 adult vaccine trial, was 22-fold higher in Chiron vaccine recipients, compared with RV144 vaccinees. CONCLUSION: As exemplified by the Chiron vaccine regimen, vaccination of infants against HIV-1 can induce robust, durable Env-specific IgG responses, including anti-V1V2 IgG.

Fostering a culture of interprofessional education for radiation therapy and medical dosimetry students.

A less-studied aspect of radiation therapy and medical dosimetry education is experiential learning through attendance at interprofessional conferences. University of North Carolina radiation therapy and medical dosimetry students regularly attended morning conferences and daily pretreatment peer review, including approximately 145 hours of direct interaction with medical attending physicians and residents, medical physicists, and other faculty. We herein assessed the effect of their participation in these interprofessional conferences on knowledge and communication. The students who graduated from our radiation therapy and medical dosimetry programs who were exposed to the interprofessional education initiative were compared with those who graduated in the previous years. The groups were compared with regard to their knowledge (as assessed by grades on end-of-training examinations) and team communication (assessed via survey). The results for the 2 groups were compared via exact tests. There was a trend for the examination scores for the 2012 cohort to be higher than for the 2007 to 2011 groups. Survey results suggested that students who attended the interprofessional education sessions were more comfortable speaking with attending physicians, residents, physicists, and faculty compared with earlier students who did not attend these educational sessions. Interprofessional education, particularly vertical integration, appears to provide an enhanced educational experience both in regard to knowledge (per the examination scores) and in building a sense of communication (via the survey results). Integration of interprofessional education into radiation therapy and medical dosimetry educational programs may represent an opportunity to enrich the learning experience in multiple ways and merits further study.

Immunogenicity of Licensed Influenza A (H1N1) 2009 Monovalent Vaccines in HIV-Infected Children and Youth.

BACKGROUND: With the emergence of pandemic influenza A (pH1N1) in 2009, children and youth infected with human immunodeficiency virus (HIV) were vulnerable because of immunologic impairment and the greater virulence of this infection in young persons. METHODS: A multicenter study of the immunogenicity of 3 licensed influenza A (H1N1) monovalent vaccines (1 live attenuated and 2 inactivated) was conducted in children and youth with perinatal HIV infection, most of whom were receiving ≥3 antiretroviral drugs, had CD4% ≥15, and plasma HIV RNA levels <400 copies/mL. Serum hemagglutinin inhibition assay (HAI) antibody levels were measured and correlated with baseline demographic and clinical variables. RESULTS: One hundred forty-nine subjects were enrolled at 26 sites in the United States and Puerto Rico. Over 40% had baseline HAI titers ≥40. For subjects aged 6 months to <10 years, 79% and 68%, respectively, achieved a ≥40- and ≥4-fold rise in HAI titers after the second dose of vaccine. Three weeks after a single immunization with an inactivated vaccine, similar immunogenicity results were achieved in youth aged 10-24 years. With multivariable analysis, only Hispanic ethnicity and CD4% ≥15 were associated with achieving both HAI titer ≥40- and ≥4-fold rise in titer. CONCLUSIONS: Although licensed pH1N1 vaccines produced HAI titers that were considered to be protective in the majority of HIV-infected children and youth, the proportion with titers ≥40- and ≥4-fold rise in titer was lower than expected for children without HIV infection. Vaccine immunogenicity was lower in HIV-infected children and youth with evidence of immune suppression.

High proportions of regulatory B and T cells are associated with decreased cellular responses to pH1N1 influenza vaccine in HIV-infected children and youth (IMPAACT P1088).

HIV-infected individuals have poor responses to inactivated influenza vaccines. To evaluate the potential role of regulatory T (Treg) and B cells (Breg), we analyzed their correlation with humoral and cell-mediated immune (CMI) responses to pandemic influenza (pH1N1) monovalent vaccine in HIV-infected children and youth. Seventy-four HIV-infected, 4- to 25-y old participants in a 2-dose pH1N1 vaccine study had circulating and pH1N1-stimulated Treg and Breg measured by flow cytometry at baseline, post-dose 1 and post-dose 2. Concomitantly, CMI was measured by ELISPOT and flow cytometry; and antibodies by hemagglutination inhibition (HAI). At baseline, most of the participants had pH1N1-specific IFNγ ELISPOT responses, whose magnitude positively correlated with the baseline pH1N1, but not with seasonal H1N1 HAI titers. pH1N1-specific IFNγ ELISPOT responses did not change post-dose 1 and significantly decreased post-dose 2. In contrast, circulating CD4+CD25+% and CD4+FOXP3+% Treg increased after vaccination. The decrease in IFNγ ELISPOT results was marginally associated with higher pH1N1-specific CD19+FOXP3+ and CD4+TGFß+% Breg and Treg, respectively. In contrast, increases in HAI titers post-dose 1 were associated with significantly higher circulating CD19+CD25+% post-dose 1, whereas increases in IFNγ ELISPOT results post-dose 1 were associated with higher circulating CD4+/C8+CD25+FOXP3+%. In conclusion, in HIV-infected children and youth, influenza-specific Treg and Breg may contribute to poor responses to vaccination. However, robust humoral and CMI responses to vaccination may result in increased circulating Treg and/or Breg, establishing a feed-back mechanism.