The levels of immune response to SARS-CoV-2 infection or vaccination are poorly understood in African populations and is complicated by cross-reactivity to endemic pathogens as well as differences in ...host responsiveness. To begin to determine the best approach to minimize false positive antibody levels to SARS-CoV-2 in an African population, we evaluated three commercial assays, namely Bio-Rad Platelia SARS-CoV-2 Total Antibody (Platelia), Quanterix Simoa Semi-Quantitative SARS-CoV-2 IgG Antibody Test (anti-Spike), and the GenScript cPass™ SARS-CoV-2 Neutralization Antibody Detection Kit (cPass) using samples collected in Mali in West Africa prior to the emergence of SARS-CoV-2. A total of one hundred samples were assayed. The samples were categorized in two groups based on the presence or absence of clinical malaria. Overall, thirteen out of one hundred (13/100) samples were false positives with the Bio-Rad Platelia assay and one of the same one hundred (1/100) was a false positive with the anti-Spike IgG Quanterix assay. None of the samples tested with the GenScript cPass assay were positive. False positives were more common in the clinical malaria group, 10/50 (20%) vs. the non-malaria group 3/50 (6%); p = 0.0374 using the Bio-Rad Platelia assay. Association between false positive results and parasitemia by Bio-Rad remained evident, after adjusting for age and sex in multivariate analyses. In summary, the impact of clinical malaria on assay performance appears to depend on the assay and/or antigen being used. A careful evaluation of any given assay in the local context is a prerequisite for reliable serological assessment of anti-SARS-CoV-2 humoral immunity.
•Fourteen out of one hundred pre-pandemic samples have detectable antibodies.•Antibodies detected do not have neutralizing capacity against SARS-CoV-2.•Relationship between false positivity and clinical malaria is assay specific.
Abstract
Background
Data on cellular immune responses in persons with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection following vaccination are limited. The evaluation of these ...patients with SARS-CoV-2 breakthrough infections may provide insight into how vaccinations limit the escalation of deleterious host inflammatory responses.
Methods
We conducted a prospective study of peripheral blood cellular immune responses to SARS-CoV-2 infection in 21 vaccinated patients, all with mild disease, and 97 unvaccinated patients stratified based on disease severity.
Results
We enrolled 118 persons (aged 50 years SD 14.5 years, 52 women) with SARS-CoV-2 infection. Compared to unvaccinated patients, vaccinated patients with breakthrough infections had a higher percentage of antigen-presenting monocytes (HLA-DR+), mature monocytes (CD83+), functionally competent T cells (CD127+), and mature neutrophils (CD10+); and lower percentages of activated T cells (CD38+), activated neutrophils (CD64+), and immature B cells (CD127+CD19+). These differences widened with increased disease severity in unvaccinated patients. Longitudinal analysis showed that cellular activation decreased over time but persisted in unvaccinated patients with mild disease at 8-month follow-up.
Conclusions
Patients with SARS-CoV-2 breakthrough infections exhibit cellular immune responses that limit the progression of inflammatory responses and suggest mechanisms by which vaccination limits disease severity. These data may have implications for developing more effective vaccines and therapies.
Clinical Trials Registration. NCT04401449.
The cellular immune signature found in vaccinated patients with breakthrough infections shows more favorable myeloid and lymphoid compartments that limit inflammatory responses associated with disease severity and may lead to a better control of viral replication and less immune activation.
Graphical Abstract
Graphical Abstract
We have recently reported that a recombinant HIV-1NL4.3 containing Met-to-Ile change at codon 50 of integrase (IN) (IN:M50I) exhibits suppression of the virus release below 0.5% of WT HIV, and the ...released viral particles are replication-incompetent due to defects in Gag/GagPol processing by inhibition of the initiation of autoprocessing of GagPol polyproteins in the virions and leads to replication-incompetent viruses. The coexisting Ser-to-Asn change at codon 17 of IN or Asn-to-Ser mutation at codon 79 of RNaseH (RH) compensated the defective IN:M50I phenotype, suggesting that both IN and RH regulate an HIV infectability. In the current study, to elucidate a distribution of the three mutations during anti-retroviral therapy among patients, we performed a population analysis using 529 plasma virus RNA sequences obtained through the MiSeq. The result demonstrated that 14 plasma HIVs contained IN:M50I without the compensatory mutations. Comparing the sequences of the 14 viruses with that of the defective virus illustrated that only Val-to-Ile change at codon 151 of IN (IN:V151I) existed in the recombinant virus. This IN:V151I is known as a polymorphic mutation and was derived from HIVNL4.3 backbone. A back-mutation at 151 from Ile-to-Val in the defective virus recovered HIV replication capability, and Western Blotting assay displayed that the back-mutation restored Gag/GagPol processing in viral particles. These results demonstrate that a combination of IN:M50I and IN:V151I mutations, but not IN:M50I alone, produces a defective virus.
Abstract
Persistent viral activity may cause enduring seropositivity and inflammation in treated people with HIV (PWH). We compared inflammatory biomarkers between early treated PWH who remained ...seronegative or seroconverted and found similar levels of D-dimer, soluble cluster of differentiation 14, C-reactive protein, and interleukin-6, indicating that seronegativity does not affect chronic inflammation in early treated PWH.
Nonnucleoside reverse transcriptase inhibitor-drug resistance mutations (DRM) are increasingly reported in Africans failing their first antiretroviral regimen. The Phidisa II trial randomized ...treatment-naive participants to lopinavir/ritonavir or efavirenz with stavudine + lamivudine or zidovudine + didanosine. We report the prevalence of DRM in subjects who achieved HIV RNA <400 copies per milliliter at 6 months, but subsequently had 2 consecutive HIV RNA >1000 copies per milliliter. Sixty-eight participants fulfilled the inclusion criteria. nonnucleoside reverse transcriptase inhibitor-DRM were found in 17 of 36 (47.2%) efavirenz recipients, and M184V/I mutation in 14 of 40 (35.0%) lamivudine recipients. No protease inhibitor mutation was identified in 38 lopinavir/ritonavir recipients. This is one of the first studies in Africa confirming the paucity of protease inhibitor-associated DRM despite virologic failure.
Study Objective. To evaluate the effect of a previous single dose of nevirapine given to prevent mother‐to‐child transmission of human immunodeficiency virus (HIV) on virologic and immunologic ...measures after 6 months of an antiretroviral regimen containing either efavirenz or lopinavir‐ritonavir.
Design. Retrospective subgroup analysis of data from the Phidisa II trial.
Setting. Six South African research clinics.
Patients. A total of 394 women with HIV who completed 6 months of combination antiretroviral regimen containing either efavirenz or lopinavir‐ritonavir as part of the Phidisa II trial.
Measurements and Main Results. During the screening process for the Phidisa II study, 478 women were asked about previous nevirapine use: 392 women (82%) were nevirapine naïve, and 86 (18%) had received nevirapine. During the study, patients received either an efavirenz‐based or lopinavir‐ritonavir‐based antiretroviral regimen. After 6 months of treatment, virologic (HIV RNA levels) and immunologic (CD4+ cell count) responses were measured. These data were compared between women with or without previous nevirapine exposure, and between women who received efavirenz versus lopinavir‐ritonavir. After 6 months of treatment, 394 women (324 nevirapine naïve, 70 exposed to nevirapine) had follow‐up HIV RNA results. Two hundred twenty‐seven (70.1%) of the nevirapine‐naïve patients and 48 (68.6%) of the nevirapine‐exposed patients achieved HIV RNA levels lower than 400 copies/ml (p=0.89), with CD4+ cell count increases of 115.5 and 120.4 cells/mm3, respectively (p=0.67). Among the nevirapine‐exposed women, 27 (75%) of 36 efavirenz‐treated and 21 (61.8%) of 34 lopinavir‐ritonavir‐treated patients had HIV RNA levels lower than 400 copies/ml at 6 months (p=0.31).
Conclusion. In this retrospective analysis of a small cohort, previous exposure to a single dose of nevirapine did not affect virologic outcomes after 6 months of either an efavirenz‐based or lopinavir‐ritonavir‐based antiretroviral regimen. As efavirenz is one of the first‐line combination antiretroviral therapies administered in Africa, it remains an option for women who received single‐dose nevirapine.
The efficacy of directly acting antiviral agents in interferon-free regimens for the treatment of chronic hepatitis C infections needs to be evaluated in different populations.
To determine the ...efficacy and safety of sofosbuvir with weight-based or low-dose ribavirin among a population with unfavorable treatment characteristics.
Single-center, randomized, 2-part, open-label phase 2 study involving 60 treatment-naive patients with hepatitis C virus (HCV) genotype 1 enrolled at the National Institutes of Health (October 2011-April 2012).
In the study's first part, 10 participants with early to moderate liver fibrosis were treated with 400 mg/d of sofosbuvir and weight-based ribavirin for 24 weeks. In the second part, 50 participants with all stages of liver fibrosis were randomized 1:1 to receive 400 mg of sofosbuvir with either weight-based or low-dose 600 mg/d of ribavirin for 24 weeks.
The primary study end point was the proportion of participants with undetectable HCV viral load 24 weeks after treatment completion (sustained virologic response of 24 weeks SVR24).
In the first part of the study, 9 participants (90%; 95% CI, 55%-100%) achieved SVR24. In the second part, 7 participants (28%) in the weight-based group and 10 (40%) in the low-dose group relapsed after treatment completion leading to SVR24 rates of 68% (95% CI, 46%-85%) in the weight-based group and 48% (95% CI, 28%-69%; P = .20) in the low-dose group. Twenty individuals participated in a pharmacokinetic-viral kinetic substudy, which demonstrated a slower loss rate of infectious virus in relapsers than in participants who achieved SVR (clearance, 3.57/d vs 5.60/d; P = .009). The most frequent adverse events were headache, anemia, fatigue, and nausea. There were 7 grade 3 events including anemia, neutropenia, nausea, hypophosphatemia, and cholelithiasis or pancreatitis. No one discontinued treatment due to adverse events.
In a population of patients with a high prevalence of unfavorable traditional predictors of treatment response, a 24-week regimen of sofosbuvir and weight-based or low-dose ribavirin resulted in SVR24 rates of 68% and 48%, respectively.
clinicaltrials.gov Identifier: NCT01441180.
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