Insufficient measles antibody protection in 6-month-old Malawian infants: Reconsider vaccination schedule?

Measles vaccination is currently recommended at 9 months, since maternal antibodies are supposed to protect infants until that age. In this study of 6-month-old Malawian infants 98.3% (58/59) had non-protective IgG levels against measles, irrespective of HIV exposure. Anticipating the first dose at 6 months could be considered.

Immunoglobulin G passive transfer from mothers to infants: total IgG, IgG subclasses and specific antipneumococcal IgG in 6-week Malawian infants exposed or unexposed to HIV.

BACKGROUND: The impaired transplacental passage of IgG from mothers living with HIV to their infants could be one of the causes of the high vulnerability to infections of HIV-exposed uninfected (HEU) infants, but controversial results have been obtained in different settings. The aim of this study was to assess in 6-week old HEU and HIV-unexposed, uninfected (HUU) Malawian infants the total IgG levels, the subclasses profile and the concentrations of global anti-pneumococcal capsular polysaccharide (anti-PCP) IgG and IgG2. METHODS: Dried blood spots were collected from 80 infants (40 HEU, 40 HUU) and antibodies concentrations determined by nephelometric method (total IgG and subclasses), or using ELISA (anti-PCP total IgG and IgG2). Results are expressed as median levels with IQR, while the proportions of each subclass out of the total IgG are used to describe the subclasses profile. RESULTS: At 6 weeks HEU infants had higher median levels of total IgG and IgG1 and a significantly lower level of IgG2 [0.376 (0.344-0.523) g/l vs 0.485 (0.374-0.781) g/l, p = 0.037] compared to the HUU counterparts. The IgG subclasses distribution confirmed the underrepresentation of IgG2 (IgG2 represented 5.82% of total IgG in HEU and 8.87% in HUU). The anti-PCP IgG and IgG2 levels were significantly lower in HEU infants [8.9 (5.4-15.1) mg/l vs 16.2 (9.61-25.8) mg/l in HUU, p < 0.001, and 2.69 (1.90-4.29) mg/l vs 4.47 (2.96-5.71) mg/l in HUU, p = 0.001, respectively]. CONCLUSION: Compared to HUU infants, HEU infants have IgG abnormalities mainly represented by low IgG2 levels, suggesting that despite maternal antiretroviral therapy, the mechanisms of IgG transplacental passage continue to be impaired in women living with HIV. HEU infants also showed a significantly lower level of specific anti-PCP IgG, possibly favouring a high vulnerability to S. pneumoniae infection at an age when protection is mostly depending on maternal IgG.

HIV-exposed infants with EBV infection have a reduced persistence of the immune response to the HBV vaccine.

BACKGROUND: In sub-Saharan African countries Epstein Barr virus (EBV) infection occurs in early childhood. We aim to investigate the factors associated with EBV acquisition and the impact of EBV infection on the humoral response to HBV vaccination in infants born from HIV-positive, antiretroviral-treated mothers in Malawi. METHODS: A total of 149 HIV-exposed infants were included in this longitudinal study. EBV anti-VCA IgG were measured using an ELISA assay. The EBV seroconversion was correlated with the maternal viro-immunological conditions, with infant growth and immunological vulnerability, and with the humoral response to the HBV vaccine. RESULTS: No infant was EBV-positive at 6 months (n. 52 tested). More than a third of infants (49/115 or 42.6 %) on study beyond 6 months seroconverted at 12 months. At 24 months, out of 66 tested infants, only 13 remained EBV-uninfected, while 53 (80.3 %) acquired EBV infection, rising the total proportion of EBV seroconversion to 88.7 % (102/115 infants). EBV seroconversion was significantly associated with a low maternal educational status but had no impact on infant growth or vulnerability to infections. Reduced HBsAb levels and accelerated waning of antibodies were associated with early EBV seroconversion. CONCLUSIONS: We found a heterogeneous timing of acquisition of EBV with the majority of infants born from HIV + mothers acquiring infection after 6 months. Anti-HBs levels were lower and appeared to wane faster in infants acquiring EBV infection.

Dynamics of immunoglobulin G subclasses during the first two years of life in Malawian infants born to HIV-positive mothers.

BACKGROUND: Maternal antibodies are key components of the protective responses of infants who are unable to produce their own IgG until 6 months of life. There is evidence that HIV-exposed uninfected children (HEU) have IgG levels abnormalities, that can be partially responsible for the higher vulnerability to infections in the first 2 years of the life of this population. This retrospective study aimed to characterize the dynamics in plasma levels of total IgG and their isotypes during the first 2 years of life in HEU infants exclusively breastfed through 6 months of age. METHODS: Total IgG, IgG1, IgG2, IgG3 and IgG4 isotypes, and IgM and IgA plasma concentrations were determined by nephelometric methods in 30 Malawian infants born to HIV-positive women at month 1, 6 and 24 of life. RESULTS: At 1-month infants had a median concentration of total IgG of 8.48 g/l, (IQR 7.57-9.15), with an overrepresentation of the IgG1 isotype (89.0% of total) and low levels of IgG2 (0.52 g/l, IQR, 0.46-0.65). Total IgG and IgG1 concentrations were lower at 6 months (- 2.1 and - 1.12 g/dl, respectively) reflecting disappearance of maternal antibodies, but at 24 months their levels were higher with respect to the reported reference values for age-matched pairs. Abnormal isotype distribution was still present at 24 months with IgG2 remaining strongly underrepresented (0.87 g/l, 7.5% of total IgG). CONCLUSION: HIV exposure during pregnancy and breastfeeding seems to influence the IgG maturation and isotype distribution that persist in 2-year old infants.

Immune Activation and Microbial Translocation Markers in HIV-Exposed Uninfected Malawian Infants in the First Year of Life.

BACKGROUND: HIV-exposed uninfected (HEU) infants show a high rate of morbidity. We aimed to investigate on biomarkers of immune activation/microbial translocation in HEU infants, evaluating the impact that infections/malnutrition can have on biomarker levels during the first year of life. METHODS: Clinical data of 72 Malawian infants were recorded monthly and correlated with levels of soluble CD14 (sCD14), lipopolysaccharide-binding protein (LBP) and intestinal fatty acid-binding protein (I-FABP), analyzed longitudinally. RESULTS: Levels of sCD14 and LBP showed a significant age-related increase. Higher levels of LBP (19.4 vs. 15.2 µg/ml) were associated with stunting, affecting 30% of the infants. The association remained statistically significant after adjusting for cytomegalovirus acquisition, malaria and respiratory infections (p = 0.031). I-FABP levels were significantly increased in infants experiencing gastrointestinal infections (1442.8 vs. 860.0 pg/ml, p = 0.018). CONCLUSION: We provide evidence that stunting is associated with an enhanced inflammatory response to microbial products in HEU children, suggesting that malnutrition status should be taken into consideration to better understand the alteration of the immune profile of HEU infants living in poor socioeconomic settings.

Antibody response to hepatitis B vaccine in HIV-exposed infants in Malawi and correlation with HBV infection acquisition.

The aim of this study was to assess the immune response to HBV vaccine in HIV-exposed infants and to correlate it to HBV infection acquisition. Protective anti-HBs levels (>10 mIU/mL) were found in 54/58 (93.2%) infants at 6 months, 126/144 (87.5%) at 12 months and 141/176 (80.1%) children at 24 months. HBV infection (seven children were HBsAg + at Month 24) occurred also in the presence of levels above 10 mIU/mL. Our findings indicate limited impact of HIV exposure on anti-HBV immune response, but suggest that levels >10 mIU/mL may be required to confer protection in this context.

Deficit of IgG2 in HIV-positive pregnant women is responsible of inadequate IgG2 levels in their HIV-uninfected children in Malawi.

BACKGROUND: Transplacental passage of IgGs is impaired in HIV + pregnant women, possibly determining an inadequate immunological protection in their children. We aimed to determine the impact of maternal immunological IgG profile and immunoactivation status on the efficiency of transplacental passage of IgG subclasses in HIV + mothers. METHODS: 16 mother/infants pairs were studied in Malawi. Mothers received antiretroviral therapy (ART) from the third trimester of pregnancy. Determinations of pre-ART levels of maternal sCD14, of IgG subclasses in mothers at delivery and in their 1-month-old infants, were performed using commercial ELISA kits. RESULTS: At delivery, after a median of 10 weeks of ART, 12/16 mothers were hypergammaglobulinemic, with IgG levels (20.5 mg/ml, 95% CI:18.8-26.8) directly correlated to the plasmatic levels of sCD14 (r = 0.640, p = 0.014). IgG1 levels (17.9 mg/ml) accounted for 82% of IgG, IgG3 and IgG4 levels were in the normal range. A profound deficit of IgG2 was observed both in mothers (0.60 mg/ml) and in infants (0.14 mg/ml). Placental transfer ratio (range 0.16-0.42) did not show a selective impairment between the different IgG subclasses. The transplacental passage of all IgG subclasses was decreased in the presence of maternal IgG over 16 mg/ml (significantly for IgG1, p = 0.031) and of high levels of sCD14 (p = 0.063). CONCLUSIONS: Transplacental passage was reduced for all IgG subclasses and inversely correlated to high levels of maternal IgGs and to the degree of immunoactivation. The profound depression of IgG2 in mothers suggests that IgG2 neonatal levels mostly reflect the maternal deficit rather than a selective impairment of IgG2 transfer.

CMV infection in a cohort of HIV-exposed infants born to mothers receiving antiretroviral therapy during pregnancy and breastfeeding.

Antiretroviral therapy has been shown to reduce rates of congenital CMV infection. Little information is available on the possible impact of antiretroviral therapy on postnatal breastfeeding-associated CMV infection acquisition. A cohort of 89 HIV-infected mothers and their children was studied. Women received antiretroviral therapy from week 25 of gestation until 6 months postpartum or indefinitely if meeting the criteria for treatment. All women were evaluated for CMV IgG presence and CMV DNA in breast milk. Children were tested for CMV infection by either the presence of IgM or the presence of CMV DNA in plasma at 1, 6 and 12 months and by the presence of IgG at 24 months. All mothers had high titers of CMV DNA in breast milk (5.7 log at Month 1 and 5.1 log at Month 6). Cumulative CMV infection rates were 60.3 % at Month 6, 69 % at Month 12 and 96.4 % at Month 24. There was a significant negative correlation between the duration of antiretroviral treatment during pregnancy and levels of CMV DNA in breast milk at Month 1 (P = 0.033). There was a trend for a correlation between high titers of CMV DNA in breast milk at 6 months and CMV infection at 6 months (P = 0.069). In this cohort, more than 95 % of the children had acquired CMV infection by 2 years of age. Besides breastfeeding, which played a major role, also horizontal transmission between 1 and 2 years was certainly relevant in determining CMV infection acquisition.

Levels of bone markers in a population of infants exposed in utero and during breastfeeding to tenofovir within an Option B+ programme in Malawi.

OBJECTIVES: No data are available on bone metabolism in infants exposed to tenofovir during breastfeeding. We investigated bone metabolism markers in the first year of life in infants from mothers who received tenofovir, lamivudine and efavirenz during pregnancy and 12 months of breastfeeding in a national Option B+ programme in Malawi. METHODS: Serum samples collected at 6 and 12 months in tenofovir-exposed infants and in a small sample of tenofovir-unexposed infants from the same clinical centre were analysed in batches for levels of bone-specific alkaline phosphatase (BAP; marker of bone formation) and of C-terminal telopeptide of type I collagen (CTX; marker of bone resorption). RESULTS: Overall, 136 tenofovir-exposed infants were evaluated. No infant had at either timepoint CTX values above the upper normal limit, while most of them had at 6 and 12 months levels of BAP above the upper normal limit for the age range. Levels of bone markers showed no differences by gender and no association with growth parameters. Tenofovir-unexposed and -exposed children had similar mean levels of bone markers at 6 months (CTX: 0.62 versus 0.55 ng/mL, P = 0.122; BAP: 384 versus 362 U/L, P = 0.631). CONCLUSIONS: No significant association between treatment with tenofovir and CTX or BAP levels was found. The high levels of BAP, coupled to the normal levels observed for CTX, might reflect primarily skeletal growth. Potential negative effects of prolonged exposure to tenofovir through breastfeeding cannot however be excluded and longitudinal studies that evaluate bone mineralization status in children enrolled in Option B+ programmes are warranted.

Reduced Plasma Levels of sCD14 and I-FABP in HIV-infected Patients with Mesalazine-treated Ulcerative Colitis.

BACKGROUND: Microbial translocation (MT) is a shared feature of HIV infection and inflammatory bowel disease (IBD). AIMS: This study was conducted to assess the impact of IBD (and particularly ulcerative colitis, UC) on plasma markers of MT and immune activation in HIV+ subjects. METHODS: A cross-sectional study was conducted in 3 groups of patients: HIV+/UC+(group HIV/UC); HIV+/UC- (group HIV); HIV-/UC+(group UC). Plasma levels of soluble CD14 (sCD14), intestinal fatty acid-binding protein (I-FABP), and endotoxin core antibodies (endoCAB) were measured as plasma markers of MT. Inflammation and immune activation were evaluated by measuring plasma levels of IL-6, IL-21, TNF-alpha, and high-sensitivity C-reactive protein (hs-CRP). T- and B-cells subpopulations were characterized by FACS analysis. RESULTS: Seven patients were enrolled in group HIV/UC, 9 in HIV, and 10 in UC. All HIV-positive patients had plasma values of HIV-1 RNA<37 copies/mL for at least 12 months and good immunological recovery. All patients with UC were treated with oral mesalazine. Markers of MT, immune activation, and inflammation were not increased in subjects with HIV/UC. In fact, they had lower levels of I-FABP (p=0.001) and sCD14 (p=0.007) when compared to other patients groups. Positive correlations were found between I-FABP and sCD14 (r=.355, p=0.076). Frequency of T- and B-cell subsets did not differ among groups. CONCLUSIONS: Our results suggest that UC does not worsen MT, inflammation, or immune activation in HIV-infected subjects. The anti-inflammatory activity of chronic mesalazine administration on intestinal mucosa may contribute to this finding.

Drug resistance mutations 18 months after discontinuation of nevirapine-based ART for prevention of mother-to-child transmission of HIV in Malawi.

OBJECTIVES: The objective of this study was to determine the prevalence of drug resistance mutations among HIV-positive women in Malawi 18 months after discontinuing nevirapine-based ART for the prevention of mother-to-child transmission. PATIENTS AND METHODS: HIV-infected antiretroviral-naive (except for single-dose nevirapine) pregnant Malawian women receiving a nevirapine-based triple antiretroviral regimen from Week 25 of gestation until 6 months of breastfeeding were included in this analysis. Drug resistance was assessed in HIV-DNA 24 months post-partum and at baseline (before the initiation of treatment). In patients with resistance, the presence of mutations was also evaluated in the corresponding plasma samples. RESULTS: Seven out of 42 (16.7%) women studied had archived drug resistance at Month 24 [six cases had NNRTI-associated mutations and two cases the M184I mutation]. In four cases, resistance mutations were already present at baseline (all NNRTI mutations). In three cases, there was an emergence of 'new' resistance (also present in the plasma in one case). Of the 35 women without resistance mutations at Month 24, only one subject had resistance mutations at baseline. Baseline resistance was significantly more common among women with mutations at 24 months compared with those harbouring a WT virus (4/7 versus 1/35, P < 0.001). CONCLUSIONS: Among women who had discontinued drugs 6 months post-partum, only 3/42 (7.1%) had accumulated new resistance mutations in HIV-DNA 2 years after delivery. These findings are reassuring in terms of the safety of the Option B strategy for the prevention of HIV mother-to-child transmission.

Laboratory confirmation of clinically diagnosed malaria in a cohort of HIV-infected mothers and their children in Malawi.

To avoid overdiagnosis, accuracy in the identification of true malaria cases is of critical importance. Samples (either whole blood, dried blood spots or plasma/serum) collected at the time of clinically diagnosed malaria episodes in a cohort of Malawian HIV-infected mothers and their children were retrospectively tested with the enzyme-linked immunosorbent assay (ELISA) for HRP-2 (histidine-rich protein 2) detection. There were 55 and 56 clinically diagnosed cases of malaria in mothers and children, respectively, with samples available for testing. Rates of laboratory-confirmed episodes were 20% (11 of 55) in mothers and 16.1% (9 of 56) in children. Hemoglobin was lower in children with confirmed malaria compared to those with clinical malaria diagnosis. The results of our study support the widespread use of rapid diagnostic tests.

Viro-immunological response and emergence of resistance in HIV-infected women receiving combination antiretroviral regimens for the prevention of mother-to-child transmission in Malawi.

OBJECTIVES: To identify factors associated with detectable viral load and the emergence of drug resistance in a cohort of HIV-infected pregnant women in Malawi receiving antiretroviral combination regimens for the prevention of mother-to-infant transmission. METHODS: The study included 260 treatment-naive women who had received a three-drug nevirapine-based regimen from week 25 of gestational age until 6 months after delivery. HIV RNA was determined at month 6 and drug resistance was assessed if viral load was >50 copies/mL. Attendance at the scheduled follow-up visits was used as an indirect measure of treatment adherence. RESULTS: The rate of detectable HIV RNA at 6 months was 9.6% (25/260). The only significant predictor of this occurrence was the presence of ≥1 missed visit during follow-up (P = 0.012). Resistance was assessed in 19 of these women: 7 (37%) had a wild-type virus and the other 12 (63%) had resistance-associated mutations (nucleoside reverse transcriptase inhibitor, 7/12; non-nucleoside reverse transcriptase inhibitor, 11/12). Three of 12 cases (25%) in which mutations were detected had a viral load <1000 copies/mL. The emergence of resistance was not correlated with the presence of baseline mutations in either plasma or archived DNA. CONCLUSIONS: In this cohort of women, detectable HIV RNA 6 months post-partum was infrequent and associated with low adherence to the treatment programme. Mutations were present in 63% of the women with detectable viral load at 6 months who had samples available for resistance testing. The impact of resistance on treatment re-initiation in women discontinuing drugs after the risk of transmission has ceased can be limited.

The impact of HBV or HCV infection in a cohort of HIV-infected pregnant women receiving a nevirapine-based antiretroviral regimen in Malawi.

BACKGROUND: Coinfection with the hepatitis viruses is common in the HIV population in sub-Saharan Africa. The aim of this study was to assess, in a cohort of HIV-infected pregnant women receiving antiretroviral drugs (ARVs), the prevalence of HBV and HCV infections and to determine the impact of these infections on the occurrence of liver toxicity and on the viro-immunological response. METHODS: Women were screened for HBsAg and HCV-RNA before starting, at week 25 of gestational age, an antiretroviral regimen consisting of lamivudine and nevirapine plus either stavudine or zidovudine. Women with CD4+ < 350/mm3 continued ARVs indefinitely, while the other women interrupted treatment 6 months postpartum (end of breastfeeding period). Both groups were followed for 2 years after delivery. Liver function was monitored by alanine aminotransferase (ALT) measurement. The Cox proportional hazards model was used to identify factors associated with the emergence of liver toxicity. RESULTS: A total of 28 women out of the 309 enrolled in the study (9.1%) were coinfected with HBV (n. 27), or HCV (n. 1). During follow-up 125 women (40.4%) developed a grade ≥ 1 ALT elevation, 28 (9.1%) a grade ≥ 2 and 6 (1.9%) an elevation defining grade 3 toxicity. In a multivariate model including age, baseline CD4+ count and hemoglobin level, the presence of either HBV or HCV infection was significantly associated with the development of an ALT increase of any grade (P = 0.035). Moderate or severe liver laboratory toxicity (grade ≥ 2) was more frequent among women with baseline CD4+ > 250/mm3 (P = 0.030). In HBV-infected women a baseline HBV-DNA level above 10,000 IU/ml was significantly associated to the development of liver toxicity of grade ≥ 1 (P = 0.040). Coinfections had no impact on the immunological and virological response to antiretroviral drugs up to 2 years after delivery. CONCLUSIONS: In this cohort of nevirapine-treated women the presence of HBV or HCV was associated only to the development of mild liver toxicity, while the occurrence of moderate or severe hepatoxicity was correlated to a baseline CD4+ count > 250/mm3. No statistically significant effect of the coinfections was observed on the efficacy of antiretroviral therapy.

Cytomegalovirus viremia in HIV-exposed and HIV-unexposed infants in Malawi.

In sub-Saharan Africa the great majority of infants acquire Cytomegalovirus (CMV) infection within the first year of life. Maternal long-term antiretroviral therapy (ART) has been suggested to reduce the rate of CMV acquisition in HIV-exposed infants. In the present study serum samples collected at 6 months of age from HIV-exposed and HIV-unexposed infants were analyzed for the presence of CMV DNA (with CMV positivity defined by levels of CMV DNA > 1000 UI/ml). Twenty out of 58 (34.5%) infants had CMV DNA > 1000 UI/ml. There was no difference in the prevalence of CMV viremia between HIV-exposed and -unexposed infants [33.3% (15/45) vs 38.5% (5/13), respectively, P = 0.488]. In the HIV-exposed group, mothers of CMV-negative infants had received a longer antiretroviral treatment before delivery in comparison to mothers of CMV-positive infants (28 vs 3 months, P = 0.187). No differences in weights and lengths at birth, and at 1, 6 and 12 months were observed between CMV-positive and CMV-negative infants. In this study, the prevalence of CMV viremia at six months of age was high in infants born to HIV-positive mothers receiving long-term ART, similar to that of HIV-unexposed infants. Considering the possible relevant impact of CMV on infant health, strategies for containment of the infection should be explored.

Micronutrient and Nutritional Status of HIV-Exposed and HIV-Unexposed Malawian Infants in the First Year of Life: Assessment of Ferritin, Vitamin A, and D Status and Its Association with Growth.

Breastfed Malawian infants from Human Immunodeficiency Virus (HIV)-uninfected and HIV-infected women who received antiretroviral therapy were followed until 12 months of age, allowing us to evaluate plasma levels of ferritin, vitamin A (as retinol-binding protein, RBP), and vitamin D (25(OH)D) at six months, as well as nutritional status and growth between six and 12 months. Ferritin and RBP levels were adjusted for inflammation. The study included 88 infants, 63 of whom were part of a recent cohort (2019-2021) that included 49 HIV-exposed but uninfected (HEU) and 14 HIV-unexposed and uninfected (HUU) infants, as well as 25 infants (all HEU) from an earlier cohort (2008-2011). No differences were observed between HEU and HUU infants regarding micronutrient levels, anthropometric indexes, growth, and rates of stunting, being underweight, or wasting. HEU infants from the earlier cohort, when compared to more recent HEU infants, had significantly worse anthropometric measures at six months and inferior growth between six and twelve months. Overall, ferritin deficiency involved 68.6% of infants, while vitamin A and vitamin D deficiency involved 8% and 1.2% of infants, respectively. Micronutrient deficiencies were not associated with HIV exposure, cohort, stunting, being underweight, or wasting. At six months, stunting, being underweight, and wasting involved 25.0%, 2.7% and 2.8% of infants, respectively, with no differences related to HIV exposure. Ferritin deficiency at six months was associated with inferior subsequent growth. In this small observational study conducted in Malawian infants, no major nutritional gap was observed between HIV-exposed and HIV-unexposed infants, though the study highlighted specific nutritional deficiencies that deserve attention. High rates of stunting and ferritin deficiency were observed in the first year of life in Malawian infants, irrespective of maternal HIV status; a significant association between ferritin deficiency and worse subsequent growth was found. Vitamin A and vitamin D deficiencies were much less frequent. Based on the data observed, nutritional interventions should give priority to the correction of ferritin deficiency and chronic undernutrition.

Rates of Seroprotection against Vaccine-Preventable Infectious Diseases in HIV-Exposed and -Unexposed Malawian Infants.

BACKGROUND: The evaluation of seroprotection rates against vaccine-preventable infectious diseases allows for the identification of risk populations. HIV-exposed infants, even if not infected with HIV, have higher morbidity and mortality in comparison to unexposed counterparts. The aim of this study was to compare the specific IgG levels against Haemophilus influenzae type-B (HiB), Hepatitis-B (HBV), and Streptococcus pneumoniae (Spn) in two groups of infants (HIV-exposed and HIV-unexposed) living in Malawi. METHODS: Blood samples from 62 infants, 49 HIV-exposed, uninfected (HEU), and born to women living with HIV and 13 HIV-unexposed and uninfected (HUU), were collected at 6 months, and specific IgG levels were determined using ELISA tests. RESULTS: The antibody levels against HiB, HBV, and Spn were similar in the two groups. At six months, all HUU infants and 81.6% of HEU infants showed seroprotective levels against HiB, while a percentage of protection varying from 80.6 to 84.6% was observed for HBV and Spn regardless of HIV exposure. Only 59.2% of HEU and 69.2% of HUU infants showed antibody protection against all three pathogens. CONCLUSIONS: These results indicate similar rates of seroprotection among HEU and HUU infants but also suggest that a consistent fraction of infants received incomplete vaccinations. Strategies to enforce participation in immunization programs in Malawi should be a health priority.

Antibody Response to the SARS-CoV-2 Vaccine and COVID-19 Vulnerability during the Omicron Pandemic in Patients with CLL: Two-Year Follow-Up of a Multicenter Study.

High morbidity and mortality due to COVID-19 were described in the pre-vaccination era in patients with chronic lymphocytic leukemia (CLL). To evaluate COVID-19 morbidity after the SARS-CoV-2 vaccine, we carried out a prospective study in 200 CLL patients. The median age of patients was 70 years; 35% showed IgG levels ≤ 550 mg/dL, 61% unmutated IGHV, and 34% showed TP53 disruption. Most patients, 83.5%, were previously treated, including 36% with ibrutinib and 37.5% with venetoclax. The serologic response rates to the second and third dose of the vaccine were 39% and 53%, respectively. With a median follow-up of 23.4 months, 41% of patients experienced COVID-19, 36.5% during the Omicron pandemic, and 10% had subsequent COVID-19 events. Severe COVID-19 requiring hospitalization was recorded in 26% of patients, and 4% died. Significant and independent factors associated with the response to the vaccine and vulnerability to COVID-19 were age (OR: 0.93; HR: 0.97) and less than 18 months between the start of targeted agents and vaccine (OR: 0.17; HR: 0.31). TP53 mutation and ≥two prior treatments also emerged as significant and independent factors associated with an increased risk of developing COVID-19 (HR: 1.85; HR: 2.08). No statistical difference in COVID-19 morbidity was found in patients with or without antibody response to the vaccine (47.5% vs. 52.5%; p = 0.21). Given the persistent risk of infection due to the continuous emergence of SARS-CoV-2 variants, our results support the importance of new vaccines and protective measures to prevent and mitigate COVID-19 in CLL patients.

Emergence of lamivudine resistance hepatitis B virus mutations in pregnant women infected with HBV and HIV receiving antiretroviral prophylaxis for the prevention of mother-to-infant transmission in Malawi.

HIV/HBV co-infection is highly prevalent in sub-Saharan Africa. The aim of this study was to determine if the use of triple combination lamivudine-containing prophylaxis for the prevention of mother-to-infant HIV transmission was associated with the emergence of lamivudine HBV mutations. The study included 21 pregnant co-infected women in Malawi who received either zidovudine or stavudine plus lamivudine and nevirapine from week 25 of gestation until 6 months after delivery or indefinitely if they met the criteria for treatment (CD4+ <350/mm(3)). HBV-DNA was determined using the Roche COBAS assay. Resistance mutations were assessed by the Trugene assay (Siemens Diagnostics). At baseline 33% of the women were HBeAg positive and had HBV-DNA > 10(4) IU/ml. Median CD4 count was 237 cells/mm(3) and median HIV-RNA was 3.8 log(10) copies/ml. After a median of 259 days of treatment, HBV-DNA was detectable in 9 out of 21 patients (42.8%). In three cases the HBV-DNA level was >10(4) IU/ml. Resistance mutations (M204I in five cases and L180M + M204I/V in one case) were present in 6 (28.6%) patients. Women with a resistant virus had significantly higher baseline HBV-DNA levels than those not developing resistance (1.1 × 10(7) IU/ml vs. 20.8 IU/ml, P = 0.022). Levels of ALT and AST were higher in women with resistant viruses compared to those retaining a wild-type virus. A high rate of lamivudine resistance was seen in this cohort of pregnant women. Follow-up of these patients will clarify if the presence of resistance has a significant impact on liver disease.

The role of IL-15 in challenging Acquired Immunodeficiency Syndrome.

OBJECTIVE: To determine the functions of in vitro primed Natural Killer (NK) cells in Human Immunodeficiency Virus (HIV-1) infection and the role of IL-2, IL-12 and IL-15 in enhancing the NK survival and activity in terms of viral suppression and of purging of HIV provirus. METHODS: Peripheral Blood Mononuclear Cells (PBMCs) and CD4+ T lymphocytes cells obtained from eight healthy donors were infected in vitro with HIV-1 and p24 was measured with and without IL-2, IL-12 and IL-15. We studied the effect of NK pulsed in vitro with IL-2, IL-12 and IL-15 on HIV replication by measurement of p-24 and DNA-provirus load when added into the culture of PBMCs and CD4+ T lymphocytes cells infected in vitro. We evaluated the effect of NK cells pulsed with IL-2, IL-12 and IL-15 on HIV replication and DNA-load into the culture of CD4+ T lymphocytes cells and PBMCs by trans-well chamber. RESULTS: We found high levels of p24 in the supernatants of PBMCs and CD4+ T lymphocytes cells cultured with IL-2, IL-12, and IL-15. We observed a significant reduction of p24 in the culture both of infected PBMCs and CD4+ T lymphocytes cells in which was added NK pulsed with IL-15. We did not obtain the some results with NK pulsed with IL-2 and IL-12. We observed a power effect of NK pulsed with IL-15 on HIV-DNA. The trans-well chamber experiments showed that the effect of NK is both direct and both mediated by realizing of soluble factors. CONCLUSIONS: This study highlights some important effects of IL 15 on NK in HIV patients anyway our results are preliminary and descriptive and others studies will be needed to provide rationale for immune therapies.