Early Cytomegalovirus Infection Research Articles

QuantiFERON monitor predicts early cytomegalovirus infection and viral burden in allogeneic hematopoietic stem cell transplantation.

Cytomegalovirus (CMV) infection is a major cause of transplantation-related morbidity and mortality. This study assessed the utility of the QuantiFERON monitor (QFM; Qiagen) for the prediction of early CMV infection and viral burden. QuantiFERON-CMV (QF-CMV; Qiagen) and QFM were measured at the post-allogeneic hematopoietic stem cell transplantation (HSCT) week 4. CMV DNA was measured at every visit until post-HSCT week 24. The QFM cutoff specific to CMV infection was established. At the post-HSCT week 4, the QFM cutoff predicting CMV infection was 86.95 IU/mL. While QF-CMV results at the post-HSCT week 4 were associated with high-level CMV infection (CMV DNA ≥ 5,000 IU/mL) but not with CMV infection (CMV DNA ≥ 500 IU/mL), QFM was associated with both CMV infection and high-level CMV infection. Both indeterminate QF-CMV and nonreactive QFM were associated with increased peak CMV DNA. Low QFM is a risk factor for CMV infection and increased CMV viral loads. QFM at post-HSCT week 4 can be utilized as an assay to predict the risk and burden of early CMV infection in HSCT recipients, in conjunction with other risk factors.

QuantiFERON monitor predicts early cytomegalovirus infection and viral burden in allogeneic hematopoietic stem cell transplantation.

Cytomegalovirus (CMV) infection is a major cause of transplantation-related morbidity and mortality. This study assessed the utility of the QuantiFERON monitor (QFM; Qiagen) for the prediction of early CMV infection and viral burden. QuantiFERON-CMV (QF-CMV; Qiagen) and QFM were measured at the post-allogeneic hematopoietic stem cell transplantation (HSCT) week 4. CMV DNA was measured at every visit until post-HSCT week 24. The QFM cutoff specific to CMV infection was established. At the post-HSCT week 4, the QFM cutoff predicting CMV infection was 86.95 IU/mL. While QF-CMV results at the post-HSCT week 4 were associated with high-level CMV infection (CMV DNA ≥ 5,000 IU/mL) but not with CMV infection (CMV DNA ≥ 500 IU/mL), QFM was associated with both CMV infection and high-level CMV infection. Both indeterminate QF-CMV and nonreactive QFM were associated with increased peak CMV DNA. Low QFM is a risk factor for CMV infection and increased CMV viral loads. QFM at post-HSCT week 4 can be utilized as an assay to predict the risk and burden of early CMV infection in HSCT recipients, in conjunction with other risk factors.

Lingering Effects of Early Institutional Rearing and Cytomegalovirus Infection on the Natural Killer Cell Repertoire of Adopted Adolescents.

Adversity during infancy can affect neurobehavioral development and perturb the maturation of physiological systems. Dysregulated immune and inflammatory responses contribute to many of the later effects on health. Whether normalization can occur following a transition to more nurturing, benevolent conditions is unclear. To assess the potential for recovery, blood samples were obtained from 45 adolescents adopted by supportive families after impoverished infancies in institutional settings (post-institutionalized, PI). Their immune profiles were compared to 39 age-matched controls raised by their biological parents (non-adopted, NA). Leukocytes were immunophenotyped, and this analysis focuses on natural killer (NK) cell populations in circulation. Cytomegalovirus (CMV) seropositivity was evaluated to determine if early infection contributed to the impact of an atypical rearing. Associations with tumor necrosis factor-alpha (TNF-α) and interferon-gamma (IFN-γ), two cytokines released by activated NK cells, were examined. Compared to the NA controls, PI adolescents had a lower percent of CD56bright NK cells in circulation, higher TNF-α levels, and were more likely to be infected with CMV. PI adolescents who were latent carriers of CMV expressed NKG2C and CD57 surface markers on more NK cells, including CD56dim lineages. The NK cell repertoire revealed lingering immune effects of early rearing while still maintaining an overall integrity and resilience.

Advances and Challenges in Cytomegalovirus Detection Methods for Liver Transplant Donors

Cytomegalovirus (CMV) infection is a highly prevalent opportunistic infection among liver transplant recipients. When the liver donor is infected with CMV, there is a risk of transmission to the recipient, leading to CMV infection. To improve the postoperative outcome of liver transplantation, it is crucial to shift the focus of CMV detection to the donor and achieve early diagnosis, as well as implement effective preventative and therapeutic measures. However, the commonly used CMV detection methods in the past had limitations that prevented their early and accurate diagnosis in liver transplant donors. This review focuses on the latest advancements in CMV detection methods that can potentially be applied to liver transplant donors. The objective is to compare and evaluate their clinical utility, thereby providing guidance and support for rapid and accurate diagnosis of CMV infection in the clinic. The clustered regularly interspaced short palindromic repeats-associated proteins (CRISPR–Cas) system-based assay emerges as a promising method for detecting the virus, offering great prospects for early and expedient CMV infection diagnosis in clinical settings.

OP02.01: Effectiveness of valaciclovir for prevention of fetal infection following early gestational primary maternal cytomegalovirus infection

OP02.01: Effectiveness of valaciclovir for prevention of fetal infection following early gestational primary maternal cytomegalovirus infection

P8.146: Early and Late-Onset Cytomegalovirus Infection Following Universal Prophylaxis in Kidney Transplant Recipients: Risk Factors and Outcome

P8.146: Early and Late-Onset Cytomegalovirus Infection Following Universal Prophylaxis in Kidney Transplant Recipients: Risk Factors and Outcome

Risk factors for CMV infection within 100 days posttransplantation in patients with acute leukemia

Three hundred fifty-nine patients with acute leukemia who received allo-HSCT at our center between January 2015 and January 2020 were retrospectively reviewed. Of 359 patients, 48.19% (173) patients experienced CMV infection within 100 days posttransplantation. In univariate and multivariate logistic analysis, haploidentical-related donor (HRD) (P < 0.001; odds ratio [OR], 5.542; 95% confidence interval [CI], 3.186-9.639), and ratio of CD3+CD8+ cells in lymphocytes <14.825% (P < 0.001; OR, 3.005; 95% CI, 1.712-5.275) were identified as 2 independent risk factors. One-year relapse rate (RR) between the CMV infection group and the non-CMV infection group was not statistically significant (18.5% vs 19.9%, P = 0.688). When we divided the total cohort into AML, ALL, and MAL subgroups, there were no significant differences as well (P = 0.138; P = 0.588; P = 0.117; respectively). In conclusion, donor type (HRD) and the insufficient recovery of CD3+CD8+ cells were independent risk factors for CMV infection within 100 days posttransplantation in patients with acute leukemia. CMV infection within 100 days did not influence the incidence of relapse in 1 year for patients with acute leukemia.

Risk of Cytomegalovirus Infection with Post-Transplantation Cyclophosphamide in Haploidentical and HLA-Matched Unrelated Donor Transplantation

Post-transplantation cyclophosphamide (PTCy) is effective for graft-versus-host disease (GVHD) prevention but is associated with an increased risk of cytomegalovirus (CMV) infection. The effect of PTCy on CMV infection in matched unrelated donor (MUD) hematopoietic stem cell transplantation (HSCT) is unclear, and whether there is any difference in CMV risk with 1 or 2 doses of PTCy is not well established. This study aimed to compare the incidence of CMV infection and the association between T cell recovery in patients who received PTCy-based GVHD prophylaxis and those who received non-PTCy-based GVHD prophylaxis. We conducted a retrospective study to compare the risk of CMV infection in 3 cohorts: cohort A (n=94), matched related donor (MRD)/MUD HSCT with calcineurin inhibitor-based GVHD prophylaxis; cohort B (n=103), MRD/MUD HSCT with 1 dose of PTCy, tacrolimus, and mycophenolate mofetil (MMF); and cohort C (n=28), haploidentical donor HSCT with 2 doses of PTCy, tacrolimus, and MMF. The day +100 cumulative incidence of CMV infection was 29% for cohort A, 39% for cohort B, and 61% for cohort C (P=.009), with no difference among the cohorts in the duration of viremia (P=.46). CD3+ and CD4+ T cell counts were significantly higher in cohort A at day +30 but not at days +60 and +90. Nonrelapse mortality (NRM) trended higher and relapse was significantly lower with PTCy. There was no difference in survival among the 3 cohorts. There is an increased risk of early CMV infection in patients receiving PTCy irrespective of donor type and number of PTCy doses compared with those not receiving PTCy. Strategies focusing on CMV prevention in PTCy recipients to mitigate the risk of NRM may lead to improved long-term outcomes.

The Impact of Letermovir (LTV) Prophylaxis on Early Cytomegalovirus Infection (CMVi) and Outcomes in the Adult Allogeneic Hematopoietic Cell Transplantation (alloHCT) Recipients with High-Risk Donor Type

The Impact of Letermovir (LTV) Prophylaxis on Early Cytomegalovirus Infection (CMVi) and Outcomes in the Adult Allogeneic Hematopoietic Cell Transplantation (alloHCT) Recipients with High-Risk Donor Type

Early-life cytomegalovirus infection is associated with gut microbiota perturbations and increased risk of atopy.

The "old friends" hypothesis posits that reduced exposure to previously ubiquitous microorganisms is one factor involved in the increased rates of allergic diseases. Cytomegalovirus (CMV) may be one of the "old friends" hypothesized to help prevent allergic diseases. We sought to elucidate whether early-life CMV infection is associated with childhood atopy via perturbations of the gut microbiota. Participants were recruited from a population-based birth cohort (CHILD study) and followed prospectively until age 5years in four Canadian cities. A total of 928 participants provided stool microbiome data, urine for CMV testing, skin prick tests, and questionnaire-based detailed environmental exposures. Cytomegalovirus infection was assessed in the first year of life while the main outcome was defined by persistent sensitization to any allergen at ages 1, 3, and 5years. Early CMV infection was associated with increased beta and decreased alpha diversity of the gut microbiota. Both changes in diversity measures and early CMV infection were associated with persistent allergic sensitization at age 5years (aOR=2.08; 95% CI: 1, 4.33). Mediation analysis demonstrated that perturbation of gut microbial composition explains 30% of the association. Early-life CMV infection is associated with an alteration in the intestinal microbiota, which mediates the effect of the infection on childhood atopy. This work indicates that preventing CMV infection would not put children at increased risk of developing atopy. Rather, a CMV vaccine, in addition to preventing CMV-associated morbidity and mortality, might reduce the risk of childhood allergic diseases.

Arf GTPases Are Required for the Establishment of the Pre-Assembly Compartment in the Early Phase of Cytomegalovirus Infection.

Shortly after entering the cells, cytomegaloviruses (CMVs) initiate massive reorganization of cellular endocytic and secretory pathways, which results in the forming of the cytoplasmic virion assembly compartment (AC). We have previously shown that the formation of AC in murine CMV- (MCMV) infected cells begins in the early phase of infection (at 4–6 hpi) with the pre-AC establishment. Pre-AC comprises membranes derived from the endosomal recycling compartment, early endosomes, and the trans-Golgi network, which is surrounded by fragmented Golgi cisterns. To explore the importance of Arf GTPases in the biogenesis of the pre-AC, we infected Balb 3T3 cells with MCMV and analyzed the expression and intracellular localization of Arf proteins in the early phases (up to 16 hpi) of infection and the development of pre-AC in cells with a knockdown of Arf protein expression by small interfering RNAs (siRNAs). Herein, we show that even in the early phase, MCMVs cause massive reorganization of the Arf system of the host cells and induce the over-recruitment of Arf proteins onto the membranes of pre-AC. Knockdown of Arf1, Arf3, Arf4, or Arf6 impaired the establishment of pre-AC. However, the knockdown of Arf1 and Arf6 also abolished the establishment of infection. Our study demonstrates that Arf GTPases are required for different steps of early cytomegalovirus infection, including the establishment of the pre-AC.

Assessment of Risk Factors and Outcome of Early Versus Late Cytomegalovirus Infection Infection in Living-related D+/R + Renal Allograft Recipients.

Introduction:Cytomegalovirus infection (CMV) in a kidney transplant recipient (KTR) is a serious complication resulting in increased morbidity, mortality and reduced graft survival. There is limited data on early (within 3 months posttransplant) CMV infection (ECMVI) vs. late CMV infection (LCMVI) in patients not receiving CMV prophylaxis. In India, majority of kidney transplants are D + R + combination. This study aimed to compare the risk factors and outcome of ECMVI vs. LCMVI in living related post-KTR.Methods:This was a single-center ambispective study of adult KTR from living donor between January 2001 and December 2015 who had CMV infection. This study had two cohorts: retrospective and prospective. Retrospective cohort included all KTR from January 2001 to September 2014. Prospective cohort included KTR who received transplants from October 2014 to December 2015. Of both cohorts, patients with early and late CMV infection were included. All patients received triple-drug immunosuppression. CMV infection was diagnosed when KTR had detectable CMV copies > 500/mL. In the prospective cohort, CMV PCR was done at 45 days, 3, 6, 9 and 12 months in all patients. Patients with CMV were treated on conventional lines. All patients were followed up till June 2016.Results:Of 2175 retrospective cohort, 97 and of the 155 prospective cohorts 75 had CMV infection, total being 172 CMV infections. Of these, 90 patients had ECNVI and 82 LCMVI. Induction was used in 48.8% in ECMVI group vs. 35.3% in LCMVI group (p = 0.02). CNI toxicity was present prior to CMV infection in 15 (17.4%) in ECMVI as compared to 14 (17.9%) in LCMVI (P = 0.93). In the ECMVI, 6 (6.6%) had acute rejection as compared to 13 (15.8%) in the LCMVI (P = 0.05). While asymptomatic CMV infection was more common in early (63.3% vs 37.8%, P = 0.001), symptomatic CMV without tissue diagnosis was more common in late (54.8% vs. 31.1%, P = 0.002). Total duration of post-transplant follow-up was 22.8 ± 22.1 months in ECMVI as compared to 49.7 + 40.9 months in the LCMVI (P < 0.001). The serum creatinine at last follow-up was 1.9 ± 1.6 mg/dL in ECMVI group and 2.4 ± 2.0 mg/dL in LCMVI (P = 0.02).Conclusion:In D+/R + living renal transplant recipients, without routine CMV prophylaxis, late CMV infection had more tissue invasive disease and is associated with inferior graft function on long-term follow-up.

Post-transplant absolute lymphocyte count predicts early cytomegalovirus infection after heart transplantation

Immunosuppressive therapy can decrease rejection episodes and increase the risk of severe and fatal infections in heart transplantation (HT) recipients. Immunosuppressive therapy can also decrease the absolute lymphocyte count (ALC), but the relationship between early post-transplant ALC and early cytomegalovirus (CMV) infection is largely unknown, especially in HT. We retrospectively analyzed 58 HT recipients who tested positive for CMV IgG antibody and received basiliximab induction therapy. We collected preoperative and 2-month postoperative data on ALC and CMV load. The CMV load > 1200 IU/mL was used as the cutoff value to define early CMV infection. Post-transplant lymphopenia was defined as an ALC of < 500 cells/μL at postoperative day (POD) #7. On POD #7, 29 (50.0%) patients had post-transplant lymphopenia and 29 (50.0%) patients did not. The incidence of CMV infection within 1 or 2 months of HT was higher in the post-transplant lymphopenia group than in the non-lymphopenia group (82.8% vs. 48.3%, P = 0.013; 89.7% vs. 65.5%, P = 0.028, respectively). ALC < 500 cells/μL on POD #7 was an independent risk factor for early CMV infection within 1 month of HT (odds ratio, 4.14; 95% confidence interval, 1.16–14.77; P = 0.029). A low ALC after HT was associated with a high risk of early CMV infection. Post-transplant ALC monitoring is simple and inexpensive and can help identify patients at high risk of early CMV infection.

Maternal CMV seroprevalence rate in early gestation and congenital cytomegalovirus infection in a Chinese population

ABSTRACT Background Congenital human cytomegalovirus (CMV) infection remains largely unrecognized and underemphasized in medical practice. This study aimed to describe the maternal CMV seroprevalence rate in early gestation and congenital CMV infection in a Chinese population. Methods This prospective cohort study was conducted in three hospitals in China from 2015 through 2018. Pregnant women were enrolled in early gestation and followed up in middle and late gestation with serological testing. CMV serostatus was determined by IgG testing in serum during early gestation. Their newborns were screened for cCMV infection by PCR testing in both saliva and urine at two time points. The cCMV prevalence, maternal seroprevalence and associated factors were analyzed. Results In China, the CMV seroprevalence was 98.11% (6602/6729, 95% CI: 97.76%–98.41%), and the cCMV prevalence was 1.32% (84/6350, 95% CI: 1.07%–1.64%). Over 98% of cCMV-positive newborns were from pregnant women who were seropositive in early gestation in China. The prevalence of cCMV infection in newborns from seropositive and seronegative pregnant women was similar (crude prevalence: 1.33% vs 0.82%, P = 1.00; estimated prevalence: 1.27% vs 1.05%, P = 0.32). Pregnant women who were under 25 years old or primiparous had a lower seroprevalence. Newborns from pregnant women under 25 years old or from twin pregnancies had a higher prevalence of cCMV infection. Conclusion in China, the cCMV prevalence was high, and the rates were similar in newborns from pregnant women who were seropositive and seronegative in early gestation. The vast majority of cCMV newborns were from seropositive mothers. Trial registration: ClinicalTrials.gov identifier: NCT02645396..

Mixed cytomegalovirus genotypes in HIV-positive mothers show compartmentalization and distinct patterns of transmission to infants.

Cytomegalovirus (CMV) is the commonest cause of congenital infection and particularly so among infants born to HIV-infected women. Studies of congenital CMV infection (cCMVi) pathogenesis are complicated by the presence of multiple infecting maternal CMV strains, especially in HIV-positive women, and the large, recombinant CMV genome. Using newly developed tools to reconstruct CMV haplotypes, we demonstrate anatomic CMV compartmentalization in five HIV-infected mothers and identify the possibility of congenitally transmitted genotypes in three of their infants. A single CMV strain was transmitted in each congenitally infected case, and all were closely related to those that predominate in the cognate maternal cervix. Compared to non-transmitted strains, these congenitally transmitted CMV strains showed statistically significant similarities in 19 genes associated with tissue tropism and immunomodulation. In all infants, incident superinfections with distinct strains from breast milk were captured during follow-up. The results represent potentially important new insights into the virologic determinants of early CMV infection.

Biological and Histological Assessment of the Hepatoportoenterostomy Role in Biliary Atresia as a Stand-Alone Procedure or as a Bridge toward Liver Transplantation.

Background and objectives: In patients with biliary atresia (BA), hepatoportoenterostomy (HPE) is still a valuable therapeutic tool for prolonged survival or a safer transition to liver transplantation. The main focus today is towards efficient screening programs, a faster diagnostic, and prompt treatment. However, the limited information on BA pathophysiology makes valuable any experience in disease management. This study aimed to analyze the evolution and survival of patients with BA referred for HPE (Kasai operation) in our department. Materials and Methods: A retrospective analysis was performed on fourteen patients with BA, diagnosed in the pediatric department and further referred for HPE in our surgical department between 2010 and 2016. After HPE, the need for transplantation was assessed according to patients cytomegalovirus (CMV) status, and histological and biochemical analysis. Follow-up results at 1–4 years and long term survival were assessed. Results: Mean age at surgery was 70 days. Surgery in patients younger than 60 days was correlated with survival. Jaundice’s clearance rate at three months was 36%. Total and direct bilirubin values had a significant variation between patients with liver transplants and native liver (p = 0.02). CMV was positive in eight patients, half with transplant need and half with native liver survival. Smooth muscle actin (SMA) positivity was proof of advanced fibrosis. The overall survival rate was 79%, with 75% for native liver patients and an 83% survival rate for those with liver transplantation. Transplantation was performed in six patients (43%), with a mean of 10 months between HPE and transplantation. Transplanted patients had better survival. Complications were diagnosed in 63% of patients. The mean follow-up period was six years. Conclusions: HPE, even performed in advanced cirrhosis, allows a significant survival, and ensures an essential time gain for patients requiring liver transplantation. A younger age at surgery is correlated with a better outcome, despite early CMV infection.

Early Ganciclovir-Resistant Cytomegalovirus Infection in a Kidney Transplant Recipient: Could We Avoid It?

Early Ganciclovir-Resistant Cytomegalovirus Infection in a Kidney Transplant Recipient: Could We Avoid It?

Comparative Study of Mizoribine and Mycophenolate Mofetil Combined with a Calcineurin Inhibitor-Based Immunosuppressive Regimen in Patients with Alternative Donor Hematopoietic Cell Transplantation.

Cytomegalovirus (CMV) infection and graft-versus-host disease (GVHD) remain the major causes of nonrelapse mortality (NRM) in patients following alternative donor hematopoietic stem cell transplantation (HCT). Mizoribine (MZR) showed an anti-CMV effect in addition to its immunosuppressive effect in patients with renal transplantation. In this study, we aimed to evaluate the efficacy and safety of MZR combined with a calcineurin inhibitor (CNI) as a method of prophylactic immunosuppression in recipients following alternative donor HCT. Eighty patients were enrolled in the study and randomized to the MZR (n=40) or MMF (n=40) cohort before transplantation conditioning. Analyses involved a comparison of the outcomes between the 2 cohorts, as well as risk analyses of early nonrelapse mortality (NRM) and severe CMV infection. In contrast to MMF, MZR was associated with a lower but statistically nonsignificant median CMV DNA peak load (P=.075), significantly fewer episodes of persistent/refractory infection (odds ratio [OR], .12), and a lower failure rate of CMV treatment (OR, .82), but a significantly higher rate of hyperuricemia (OR, 2.75). Transplantation efficacy was comparable in the 2 cohorts regarding engraftment, the development of secondary poor graft function and GVHD, and the estimated OS and PFS. The 1-year NRM of the MZR cohort did not differ from that of the MMF cohort, whereas the rate of 1-year NRM caused by viral infections was reduced in the MZR cohort and was of borderline statistical significance (P=.05). In the multivariate analysis, lower doses of CD34+ cells in grafts (hazard ratio [HR], 3.65) and persistent/refractory CMV infections (versus no CMV infection: HR, 7.31; versus CMV infection that was not persistent/refractory: HR, 4.46) were predictors of increased 1-year NRM. The use of MMF (versus MZR cohort: OR, 11.54) and grade II-IV acute GVHD (OR, 15.32) were independent risk factors for developing persistent/refractory CMV infection. When combined with CNIs, MZR functioned well in terms of both immunosuppression and reduced severity of CMV infection; however, further studies are warranted to verify its use as a potential immunosuppressant for alternative donor HCT.

Impact of normothermic ex vivo lung perfusion on early post-transplantation cytomegalovirus infection.

BackgroundThe low acceptance rates in lung transplantation underline the importance to use every potential transplantable organ. With the use of normothermic ex vivo lung perfusion (EVLP) there is a potential to use more donor lungs for transplantation. Aim of this study was to evaluate if EVLP has an effect on cytomegalovirus (CMV) infection after lung transplantation.MethodsBetween May 2016 and October 2018, 57 lung transplants were performed. Out of these 21 extended criteria lungs were evaluated by EVLP and 16 transplanted. In a retrospective study, results of EVLP treated lungs were compared with lungs after cold storage preservation (CSP). Donor/recipient CMV IgG status and seroconversion rate was examined.ResultsDonors were CMV IgG+ in EVLP 69% and CSP 61% (n.s.). Best pO2 on procurement at FiO2 1.0 was in EVLP 278±76 versus CSP 413±96 mmHg (P≤0.05). Recipients were CMV IgG+ in EVLP 38% and CSP 63% (P<0.07). CMV seroconversion: EVLP 12%, CSP 20% (P<0.05), in the CSP group in 5% recipients with more than 1,000 copies/mL were diagnosed by PCR and treated for CMV infection. Procalcitonin (PCT) levels from day 1 to day 5 were significantly lower for CSP group (P<0.05). 30-day mortality was 12% for EVLP recipients.ConclusionsNormothermic EVLP did not influence CMV infection rate, however early PCT levels were higher in EVLP group. Short-term results were comparable to standard lung transplantation.

Human Immunodeficiency Virus Exposure but Not Early Cytomegalovirus Infection Is Associated With Increased Hospitalization and Decreased Memory T-Cell Responses to Tetanus Vaccine.

Human immunodeficiency virus (HIV)-exposed, uninfected (HEU) infants experience high rates of infectious morbidity. We hypothesized that early cytomegalovirus (CMV) infection was associated with increased hospitalization rates and decreased vaccine responses in HEU compared with HIV-unexposed (HUU) infants. Among infants enrolled in the Tshipidi study in Botswana, we determined CMV infection status by 6 months of age and compared hospitalization rates and responses to tetanus and Bacille Calmette-Guérin vaccines among HEU and HUU vaccinees. Fifteen of 226 (6.6%) HEU infants and 17 (19.3%) of 88 HUU infants were CMV-infected by 6 months. The HEU infants were approximately 3 times as likely to be hospitalized compared with HUU infants (P = .02). The HEU peripheral blood cells produced less interleukin (IL)-2 (P = .004), but similar amounts of interferon-γ, after stimulation with tetanus toxoid. Antitetanus immunoglobulin G titers were similar between groups. Cellular responses to purified protein derivative stimulation did not differ between groups. Maternal receipt of 3-drug antiretroviral therapy compared with zidovudine was associated with increased IL-2 expression after tetanus toxoid stimulation. The infants' CMV infection status was not associated with clinical or vaccine response outcomes. We observed that increased rates of hospitalization and decreased memory T-cell responses to tetanus vaccine were associated with HIV exposure and incomplete treatment of maternal HIV infection, but not early CMV infection.