Payload-delivering engineered γδ T cells display enhanced cytotoxicity, persistence, and efficacy in preclinical models of osteosarcoma.

T cell-based cancer immunotherapy has typically relied on membrane-bound cytotoxicity enhancers such as chimeric antigen receptors expressed in autologous αß T cells. These approaches are limited by tonic signaling of synthetic constructs and costs associated with manufacturing. γδ T cells are an emerging alternative for cellular therapy, having innate antitumor activity, potent antibody-dependent cellular cytotoxicity, and minimal alloreactivity. We present an immunotherapeutic platform technology built around the innate properties of the Vγ9Vδ2 T cell, harnessing specific characteristics of this cell type and offering an allocompatible cellular therapy that recruits bystander immunity. We engineered γδ T cells to secrete synthetic tumor-targeting opsonins in the form of an scFv-Fc fusion protein and a mitogenic IL-15Rα-IL-15 fusion protein (stIL15). Using GD2 as a model antigen, we show that GD2-specific opsonin-secreting Vγ9Vδ2 T cells (stIL15-OPS-γδ T cells) have enhanced cytotoxicity and promote bystander activity of other lymphoid and myeloid cells. Secretion of stIL-15 abrogated the need for exogenous cytokine supplementation and further mediated activation of bystander natural killer cells. Compared with unmodified γδ T cells, stIL15-OPS-γδ T cells exhibited superior in vivo control of subcutaneous tumors and persistence in the blood. Moreover, stIL15-OPS-γδ T cells were efficacious against patient-derived osteosarcomas in animal models and in vitro, where efficacy could be boosted with the addition of zoledronic acid. Together, the data identify stIL15-OPS-γδ T cells as a candidate allogeneic cell therapy platform combining direct cytolysis with bystander activation to promote tumor control.

CRISPR-Cas enzymes: The toolkit revolutionizing diagnostics.

The programmable nature of sequence-specific targeting by CRISPR-Cas nucleases has revolutionized a wide range of genomic applications and is now emerging as a method for nucleic acid detection. We explore how the diversity of CRISPR systems and their fundamental mechanisms have given rise to a wave of new methods for target recognition and readout. These cross-disciplinary advances found at the intersection of CRISPR biology and engineering have led to the ability to rapidly generate solutions for emerging global challenges like the COVID-19 pandemic. We further discuss the advances and potential for CRISPR-based detection to have an impact across a continuum of diagnostic applications.

Armored CAR T-Cells: The Next Chapter in T-Cell Cancer Immunotherapy.

Chimeric antigen receptor (CAR) T-cell therapy engineers T-cells to express a synthetic receptor which redirects effector function to the tumor, to improve efficacy and reduce toxicities associated with conventional treatments, such as radiotherapy and chemotherapy. This approach has proved effective in treating hematological malignancies; however, the same effects have not been observed in solid tumors. The immunosuppressive tumor microenvironment (TME) creates a significant barrier to solid tumor efficacy and reduces the anti-cancer activity of endogenous tumor-resident immune cells, enabling cancer progression. In recent years, researchers have attempted to enhance CAR T-cell function in the TME by engineering the cells to express various proteins alongside the CAR. Examples of this engineering include inducing CAR T-cells to secrete cytokines or express cytokine receptors to modulate the cytokine milieu of the TME. Alternatively, the CAR T-cell may secrete antibody-like proteins to target a range of tumor antigens. Collectively, these methods are termed armored CAR T-cell therapy, and in this review, we will discuss the range of armored CAR T-cell approaches which have been investigated to date.

Space Biology Research and Biosensor Technologies: Past, Present, and Future.

In light of future missions beyond low Earth orbit (LEO) and the potential establishment of bases on the Moon and Mars, the effects of the deep space environment on biology need to be examined in order to develop protective countermeasures. Although many biological experiments have been performed in space since the 1960s, most have occurred in LEO and for only short periods of time. These LEO missions have studied many biological phenomena in a variety of model organisms, and have utilized a broad range of technologies. However, given the constraints of the deep space environment, upcoming deep space biological missions will be largely limited to microbial organisms and plant seeds using miniaturized technologies. Small satellites such as CubeSats are capable of querying relevant space environments using novel, miniaturized instruments and biosensors. CubeSats also provide a low-cost alternative to larger, more complex missions, and require minimal crew support, if any. Several have been deployed in LEO, but the next iterations of biological CubeSats will travel beyond LEO. They will utilize biosensors that can better elucidate the effects of the space environment on biology, allowing humanity to return safely to deep space, venturing farther than ever before.

Antimicrobial carbon nanodots: photodynamic inactivation and dark antimicrobial effects on bacteria by brominated carbon nanodots.

The evolving threat of antibiotic resistance development in pathogenic bacteria necessitates the continued cultivation of new technologies and agents to mitigate associated negative health impacts globally. It is no surprise that infection prevention and control are cited by the Centers for Disease Control and Prevention (CDC) as two routes for combating this dangerous trend. One technology that has gained great research interest is antimicrobial photodynamic inactivation of bacteria, or APDI. This technique permits controllable activation of antimicrobial effects by combining specific light excitation with the photodynamic properties of a photosensitizer; when activated, the photosensitizer generates reactive oxygen species (ROS) from molecular oxygen via either a type I (electron transfer) or type II (energy transfer) pathway. These species subsequently inflict oxidative damage on nearby bacteria, resulting in suppressed growth and cell death. To date, small molecule photosensitizers have been developed, yet the scalability of these as widespread sterilization agents is limited due to complex and costly synthetic procedures. Herein we report the use of brominated carbon nanodots (BrCND) as new photosensitizers for APDI. These combustion byproducts are easily and inexpensively collected; incorporation of bromine into the nanodot permits photosensitization effects that are not inherent to the carbon nanodot structure alone-a consequence of triplet character gained by the heavy atom effect. BrCND demonstrate both type I and type II photosensitization under UV-A irradiation, and furthermore are shown to have significant antimicrobial effects against both Gram-negative Escherichia coli and Gram-positive Staphylococcus aureus and Listeria monocytogenes as well. A mechanism of "dark" toxicity is additionally reported; the pH-triggered release of reactive nitrogen species is detected from a carbon nanodot structure for the first time. The results described present the BrCND structure as a competitive new antimicrobial agent for controllable sterilization of bacteria.

Fluorophore-Induced Plasmonic Current: Generation-Based Detection of Singlet Oxygen.

In this work, we report the surface-based electrical detection of singlet oxygen using the emerging fluorophore-induced plasmonic current (PC) technique. By this method, we utilize the fluorescent "turn on" response of the well-known singlet oxygen sensor green (SOSG) singlet oxygen (1O2) fluorescent probe for the generation of fluorophore-induced PC in a silver nanoparticle film. To demonstrate the potential utility of this new technique, a photosensitizing molecule is used to generate 1O2 in a solution containing the SOSG probe. The resulting change in SOSG fluorescence quantum yield and extinction coefficient permits stronger energy transfer from the SOSG probe to a proximal silver nanoparticle island film located in the near-electric field of the probe. This yields an increase in the induced electric current flow, allowing for the detection of the 1O2 analyte. To the author's knowledge, this represents the first detection of the reactive oxygen species 1O2 utilizing fluorophore-induced PC methodology and even broader electrical detection of 1O2. This is significant as it opens the possibility for 1O2 detection methods which do not require a traditional "photodetector" and associated optics, simplifying the instrumentation over existing fluorescence detection methods and potentially even lowering the cost.

Effects of partial- or whole-body exposures to 56Fe particles on brain function and cognitive performance in rats.

On exploratory class missions, such as a mission to Mars, astronauts will be exposed to particles of high energy and charge (HZE particles). Exposure to HZE particles produces changes in neuronal function and can disrupt cognitive performance. Cells throughout the entire body, not just the brain, will be impacted by these particles. To determine the possible effects that irradiation of the body might have on neuronal function and cognitive performance, rats were given head-only, body-only or whole-body exposures to 56Fe particles. Cognitive performance (novel object recognition, operant responding) was tested in one set of animals; changes in brain function (oxidative stress, neuroinflammation) was tested in a second set of rats. The results indicated that there were no consistent differences in either behavioral or neurochemical endpoints as a function of the location of the irradiation. These results suggest that radiation to the body can impact the brain, therefore it may be necessary to re-evaluate the estimates of the risk of HZE particle-induced changes in neuronal function and cognitive performance.

CYP2B6 genotype-directed dosing is required for optimal efavirenz exposure in children 3-36 months with HIV infection.

OBJECTIVES: To determine safety-specific, efficacy-specific and genotypic-specific dose requirements of efavirenz (EFV) in children aged 3 to less than 36 months with HIV infection. DESIGN: IMPAACT P1070 was a 24-week prospective cohort trial of EFV (as open capsules) and two nucleoside reverse transcriptase inhibitors in children with HIV infection 3 to less than 36 months without tuberculosis (Cohort 1). METHODS: CYP2B6 G516T genotype was determined, and intensive pharmacokinetics was performed at week 2. EFV dose was adjusted if outside the target area under the curve (AUC) 35-180 µg*h/ml. Pharmacokinetic and CYP2B6 G516T genotype data were used to model EFV exposures based on Food and Drug Administration (FDA)-approved doses. RESULTS: Forty-seven participants, median age 19 months, initiated the study regimen with 24 weeks median follow-up; 38 516GG/GT and 9 516TT genotypes. Initially, median EFV AUC was higher in 516TT vs. 516GG/GT (median 490 vs. 107 µg*h/ml; P = 0.0001) with all 516TT above AUC target. Following an amendment that reduced the 516TT EFV dose by 75%, pharmacokinetic modeling predicted that 83% of participants met the AUC target (31/38 516GG/GT, 8/9 516TT). In contrast, modeling using P1070 data predicted that FDA-approved doses would produce subtherapeutic AUCs in almost one-third of participants with 516GG/GT and excessive AUCs in more than 50% with 516TT genotypes. CONCLUSION: CYP2B6 G516T genotype strongly influences EFV exposures in this age group. Genotype-directed dosing yields therapeutic EFV concentrations and appears to outperform other dosing approaches.

Raltegravir pharmacokinetics during pregnancy.

OBJECTIVE: We evaluated the pharmacokinetics (PK) of raltegravir in HIV-infected women during pregnancy and postpartum. METHODS: International Maternal Pediatric Adolescent AIDS Clinical Trials 1026s is an ongoing prospective study of antiretroviral PK during pregnancy (NCT00042289). Women receiving 400 mg raltegravir twice daily in combination antiretroviral therapy had intensive steady-state 12-hour PK profiles performed during pregnancy and at 6- to 12-week postpartum. Targets were trough concentration above 0.035 µg/mL, the estimated 10th percentile in nonpregnant historical controls. RESULTS: Median raltegravir area under the curve was 6.6 µg·h/mL for second trimester (n = 16), 5.4 µg·h/mL for third trimester (n = 41), and 11.6 µg·h/mL postpartum (n = 38) (P = 0.03 postpartum vs second trimester, P = 0.001 pp vs third trimester). Trough concentrations were above the target in 69%, 80%, and 79% of second trimester, third trimester, and postpartum subjects, respectively, with wide variability (<0.010-0.917 µg/mL), and no significant difference between third trimester and postpartum trough concentrations was detected. The median ratio of cord blood/maternal raltegravir concentrations was 1.5. HIV RNA levels were <400 copies per milliliter in 92% of women at delivery. Adverse events included elevated liver transaminases in 1 woman and vomiting in 1. All infants with known status are HIV uninfected. CONCLUSIONS: Median raltegravir area under the curve was reduced by approximately 50% during pregnancy; trough concentrations were frequently below target both during late pregnancy and postpartum. Raltegravir readily crossed the placenta. High rates of viral suppression at delivery and the lack of a clear relationship between raltegravir concentration and virologic effect in nonpregnant adults suggest that despite the decreased exposure during pregnancy, a higher dose is not necessary.

Pharmacokinetics of an increased atazanavir dose with and without tenofovir during the third trimester of pregnancy.

BACKGROUND: Reduced atazanavir exposure has been demonstrated during pregnancy with standard atazanavir/ritonavir dosing. We studied an increased dose during the third trimester of pregnancy. METHODS: International Maternal Pediatric Adolescent AIDS Clinical Trials Group 1026s is a prospective, nonblinded, pharmacokinetic study of HIV-infected pregnant women taking antiretrovirals for clinical indications, including 2 cohorts (with or without tenofovir) receiving atazanavir/ritonavir 300/100 mg once daily during the second trimester, 400/100 mg during the third trimester, and 300/100 mg postpartum (PP). Intensive steady-state 24-hour pharmacokinetic profiles were performed. Atazanavir concentrations were measured by high-performance liquid chromatography. Pharmacokinetic targets were the 10th percentile atazanavir area under the concentration versus time curve (AUC) (29.4 µg·hr·mL·) in nonpregnant adults on standard dose and 0.15 µg/mL, minimum trough concentration. RESULTS: Atazanavir pharmacokinetic data were available for 37 women without tenofovir, 35 with tenofovir; median (range) pharmacokinetic parameters are presented for second trimester, third trimester, and PP and number who met target/total. ATAZANAVIR WITHOUT TENOFOVIR: AUC 30.5 (9.19-93.8), 45.7 (11-88.3), and 48.8 (9.9-112.2) µg·hr·mL, and 8/14, 29/37, and 27/34 met target. C24 h was 0.49 (0.09-4.09), 0.71 (0.14-2.09), and 0.90 (0.05-2.73) µg/mL; 13/14, 36/37, and 29/34 met target. ATAZANAVIR WITH TENOFOVIR: AUC 26.2 (6.8-60.9) (P < 0.05 compared with PP), 37.7 (0.72-88.2) (P < 0.05 compared with PP), and 58.6 (6-149) µg·hr·mL, and 7/17, 23/32, and 27/29 met target. C24 h was 0.44 (0.12-1.06) (P < 0.05 compared with PP), 0.57 (0.02-2.06) (P < 0.05 compared with PP), and 1.26 (0.09-5.43) µg/mL; 7/17, 23/32, and 27/29 met target. Atazanavir/ritonavir was well tolerated with no unanticipated adverse events. CONCLUSIONS: Atazanavir/ritonavir increased to 400/100 mg provides adequate atazanavir exposure during the third trimester and should be considered during the second trimester.

Aliskiren in Patients Failing to Achieve Blood Pressure Targets With Angiotensin Converting Enzyme Inhibitors or Angiotensin Receptor Blockers.

BACKGROUND: To assess the efficacy of aliskiren in patients failing to reach blood pressure (BP) goals with angiotensin converting enzyme inhibitor (ACEI) or angiotensin receptor blocker (ARB). METHODS: A total of 107 patients who failed to reach BP goals on ACEI or ARB were switched to aliskiren. Changes in BP were determined during maximal ACEI, ARB, or aliskiren therapy. RESULTS: Mean reduction in sBP and dBP with ACEI was 8.5 ± 6.3 mmHg and 6.0 ± 4.7 mmHg, respectively. Mean reduction in sBP and dBP with ARB was 8.3 ± 6.7 mmHg and 5.0 ± 5.2 mmHg, respectively. Mean reduction in sBP and dBP with aliskiren 150 mg/d was 6.7 ± 5.4 mmHg and 5.4 ± 4.8 mmHg, respectively. Mean reduction in sBP and dBP with aliskiren 300 mg/d was 8.6 ± 6.3 mmHg and 6.0 ± 4.9 mmHg, respectively. BP reductions between ACEI, ARB, and aliskiren were not significantly different. CONCLUSIONS: Aliskiren is ineffective in patients failing ACEI or ARB therapy. Given the label changes restricting the use of aliskiren in combination with ACEI and ARB, excess cost compared to ACEI and ARB, and a paucity of outcome data, there is a limited role for aliskiren in practice.

Atazanavir pharmacokinetics with and without tenofovir during pregnancy.

BACKGROUND: Few data are available describing atazanavir exposure during pregnancy, especially when used in combination with tenofovir, whose coadministration with atazanavir results in decreased atazanavir exposure. DESIGN: International Maternal Pediatric Adolescent AIDS Clinical Trials 1026 s is an ongoing, prospective, nonblinded study of antiretroviral pharmacokinetics in HIV-infected pregnant women that included 2 cohorts receiving atazanavir/ritonavir 300 mg/100 mg once daily, either with or without tenofovir. METHODS: Intensive steady-state 24-hour pharmacokinetic profiles were performed during the third trimester and at 6-12 weeks postpartum. Atazanavir was measured by reverse-phase high-performance liquid chromatography (detection limit 0.047 mcg/mL). Pharmacokinetic targets were the estimated 10th percentile atazanavir area under the concentration versus time curve [(AUC): 29.4 mcg · hr · mL-1] in nonpregnant historical controls (mean AUC = 57 mcg · hr · mL-1) and a trough concentration of 0.15 mcg/mL, the concentration target used in therapeutic drug monitoring programs. RESULTS: Median atazanavir AUC was reduced during the third trimester compared with postpartum for subjects not receiving tenofovir (41.9 vs. 57.9 mcg · hr · mL-1, P = 0.02) and for subjects receiving tenofovir (28.8 vs. 39.6 mcg · hr · mL-1, P = 0.04). During the third trimester, AUC was below the target in 33% (6 of 18) of women not receiving tenofovir and 55% (11 of 20) of women receiving tenofovir. Trough concentration was below the target in 6% (1 of 18) of women not receiving tenofovir and 15% (3 of 20) of women receiving tenofovir. The median (range) ratio of cord blood/maternal atazanavir concentration in 29-paired samples was 0.18 (0-0.45). CONCLUSIONS: Atazanavir exposure is reduced by pregnancy and by concomitant tenofovir use. A dose increase of atazanavir/ritonavir to 400 mg/100 mg may be necessary in pregnant women to ensure atazanavir exposure equivalent to that seen in nonpregnant adults.

Whistle emissions of Indo-Pacific bottlenose dolphins (Tursiops aduncus) differ with group composition and surface behaviors.

The intricate and highly developed acoustic communication system of bottlenose dolphins reflects the complexities of their social organization. Indo-Pacific bottlenose dolphins (Tursiops aduncus) produce numerous types of acoustic emissions, including a diverse repertoire of whistles used for communicative purposes. The influence of group composition on whistle production and the function of different whistles produced by dolphins in wild contexts are relatively unknown. Recordings of acoustic emissions and behavior of dolphins were made concurrently during vessel-based surveys along the coast of northern New South Wales, Australia. Whistles were divided into five tonal classes (sine, rise, down-sweep, flat, and concave) and categorized into distinct whistle types. It is shown that while whistle repetition rate and whistle diversity was influenced by group composition, it is not influenced by behavior. Noncalf groups produced a significantly higher whistle repetition rate and whistle diversity than calf groups. In contrast, the types of whistles produced were related to the behavior in which the dolphins were engaged in: some tonal classes and distinct whistle types were related to different behavior states. Findings suggested that some whistle types may be used to communicate specific information on the behavioral context of the individuals involved.

A tale of two systems: co-occurring mental health and substance abuse disorders treatment for adolescents.

Co-occurring disorders present serious challenges to traditional mental health and substance abuse treatment systems. Among adolescents in need of behavioral health services, co-occurring disorders are highly prevalent and difficult to treat. Without effective intervention, youth with co-occurring disorders are at increased risk of serious medical and legal problems, incarceration, suicide, school difficulties and dropout, unemployment, and poor interpersonal relationships. In general, current service systems are inadequately prepared to meet this need due to a variety of clinical, administrative, financial, and policy barriers. This article presents an overview of co-occurring disorders among adolescents, highlights general considerations for co-occurring disorders treatment, reviews selected treatment models and outcomes, and discusses recommendations and best practice strategies.

Safety and immunogenicity of an HIV-1 recombinant canarypox vaccine in newborns and infants of HIV-1-infected women.

Pediatric AIDS Clinical Trials Group protocol 326 is a study of 2 formulations of recombinant canarypox ALVAC vaccine (vCP205) against human immunodeficiency virus type 1 (HIV-1). HIV-1-exposed infants were randomized to receive 1 of 2 formulations of vCP205 or placebo at birth and 4, 8, and 12 weeks. The vaccines were safe. Lymphoproliferative responses were detected at > or =2 time points in 44%-56% of vaccinees and none of the placebo recipients. A cytotoxic T lymphocyte response on at least 1 occasion was detected in 62.5% of infants in cohort 1 (10(6.08) median tissue culture dose [TCID(50)] vaccine formulation) and 44% of infants in cohort 2 (10(6.33) TCID(50) vaccine formulation). Rare mucosal immunoglobulin A responses and no measurable vaccine-elicited serum antibodies were detected. In children, vCP205 appeared to be safe and immunogenic.

Long term tolerability and safety of enfuvirtide for human immunodeficiency virus 1-infected children.

BACKGROUND: Enfuvirtide, a peptide inhibitor of human immunodeficiency virus (HIV)-1-host cell membrane fusion, is the first of a new class of antiretroviral agents, the entry inhibitors. The safety and antiretroviral activity of enfuvirtide treatment of 24 weeks in HIV-1-infected children has been previously documented. Here we present the long term tolerability and safety of enfuvirtide. METHODS: Fourteen children, 4 to 12 years of age, with incompletely suppressed HIV-1 infection were evaluated. Enfuvirtide was administered twice daily by subcutaneous injection. After the first 24 weeks of enfuvirtide dosing, subjects were evaluated every 8 weeks up to 96 weeks of therapy. At each visit, each subject had a physical examination and an assessment for adverse events with particular attention to evaluation of injection site reactions. Laboratory studies obtained at each visit included hematology and blood chemistry values, plasma HIV-1 RNA concentrations and CD4+ T cell counts. RESULTS: Of 14 subjects, 6 completed at least 96 weeks of treatment. One child discontinued enfuvirtide after 22 days of treatment because of an aversion to injections, and 1 child electively discontinued after week 24 because of surgical complications unrelated to study drug. Four subjects discontinued study because of virologic failure, defined as an increase or persistence of plasma HIV-1 RNA 1.0 copies/mL above baseline, which occurred between >or =log10 weeks 40 and 63. Two children experienced grade 3 adverse events resulting in discontinuation of the study drug; 1 subject developed grade 3 thrombocytopenia and 1 developed grade 3 edema at weeks 65 and 77, respectively. Eleven of 14 children had local injection site reactions during the first 24 weeks of treatment, 4 of the 12 subjects who continued treatment beyond week 24 reported local reactions. Generally, these local reactions were 1- to 3-cm tender nodules that developed after the injections and lasted for 1-2 days. Twelve children developed new diagnoses during treatment with enfuvirtide. None was judged to be definitively related to the study drug. Thirty-six percent of children starting enfuvirtide had HIV-1 RNA levels > 1 log10 copies/mL below baseline levels at week 96. Children remaining on enfuvirtide for the entire 96 weeks had a median of 65 cells/mm and 9% increase in CD4+ T cells. CONCLUSIONS: Enfuvirtide was generally safe and, except for a high rate of injection site reactions, well-tolerated in HIV-1-infected children for as long as 96 weeks.

Preventing substance abuse in American Indian and Alaska native youth: promising strategies for healthier communities.

Substance abuse has had profoundly devastating effects on the health and well-being of American Indians and Alaska Natives. A wide variety of intervention methods has been used to prevent or stem the development of alcohol and drug problems in Indian youth, but there is little empirical research evaluating these efforts. This article is an overview of the published literature on substance use prevention among Indian adolescents, providing background epidemiological information, a review of programs developed specifically for Indian adolescents, and recommendations for the most promising prevention strategies currently in practice.

Journeys of the Circle: a culturally congruent life skills intervention for adolescent Indian drinking.

There has been an increasing call for and development of culturally appropriate substance prevention/intervention for ethnic minorities in schools and communities, especially among reservation and in urban American Indian and Alaska Native (AIAN) communities. Past attempts to intervene in and reduce misuse of alcohol and other drugs have not had great success. The Journeys of the Circle Project utilized innovative programs with a strong emphasis on historic cultural traditions.

Safety and immunogenicity of a heptavalent pneumococcal conjugate vaccine in infants with human immunodeficiency virus type 1 infection.

OBJECTIVE: Heptavalent pneumococcal conjugate vaccine (PCV) has been shown to be safe and effective in healthy infants and children. However, little is known about its use in children who have human immunodeficiency virus (HIV) infection and are known to be at increased risk of developing pneumococcal infections. This study was conducted to evaluate the safety and immunogenicity of heptavalent PCV in infants with HIV infection. METHODS: The Pediatric AIDS Clinical Trials Group Study 292 Team randomized infants with HIV infection 2:1 to receive heptavalent PCV or placebo in a double-blinded manner. Infants were vaccinated with 3 doses at 2-month intervals, starting at ages 56 to 180 days. A booster dose was given at 15 months of age. Immunogenicity was evaluated after the third dose of vaccine, before and after the booster dose, and at 24 months of age. RESULTS: Thirty infants with HIV infection received PCV, and 15 received placebo. No differences in baseline characteristics were found across arms. Five severe acute reactions were experienced by 4 subjects: 3 in the PCV arm and 1 in the placebo arm; all occurred among subjects with symptomatic disease at study entry. No differences were found in the 2 arms with respect to the number or timing of new diagnoses through 24 months of age, including diagnoses of otitis media. However, when symptomatic subjects were examined separately, the first new diagnosis occurred more rapidly among PCV recipients. Three deaths, all judged to be unrelated to study vaccine, occurred during follow-up: 2 in the PCV arm and 1 in the placebo arm. The primary immunogenicity measures were based on composites of 4-fold changes in serotype-specific immunoglobulin G titers from preimmunization levels. We found a highly significant difference between the vaccine and placebo arms, with the PCV arm showing higher rates of response. Asymptomatic and symptomatic subjects who received PCV had similar immunologic responses for all serotypes. CONCLUSIONS: This study demonstrates that heptavalent PCV was well tolerated and not associated with vaccine-associated adverse reactions. Most important, this vaccine was immunogenic in the infant with HIV infection. However, additional studies of this vaccine (or others) must pay special attention to patients with symptomatic HIV disease, as they seem to be at higher risk for adverse events to any antigen.