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The purpose of this study is to investigate the effect of Reduning injection (RI) on influenza A virus (IAV) and its mechanism. We evaluated the cytotoxicity of RI in A549 and MDCK cells by cell counting kit-8 (CCK-8) assay. Western blot and cytopathic effect (CPE) assays were applied to test the effects of RI on viral protein, CPE and virus virulence to evaluate its inhibitory effect. The proteins level of heme oxygenase 1 (HO-1), nuclear factor erythroid 2-related factor 2 (Nrf2), phosphorylation of P38 mitogen-activated protein kinases (MAPK) and extracellular signal-regulated kinases 1/2 (ERK1/2) were detected by Western blot. Real-time fluorescence quantitative PCR (qRT-PCR) was used to detect the RNA expression of interferon-α/β (IFN-α/β). The relative luciferase reporter assay was used to analyze the promoter activity and transcriptional regulation of Nrf2. The results indicated that RI inhibited IAV-induced MDCK cytopathies in a dose-dependent manner, decreased M2 protein of influenza virus and viral titer, indicating that it has definite effect on inhibiting IAV. RI promotes the phosphorylation of P38 MAPK and ERK1/2, activates the activity of Nrf2 nuclear transcription factor, increases the expression of Nrf2 protein in the nucleus, thus up-regulates the expression of HO-1 protein, and ultimately increases the IFN-α/β mRNA level. In summary, our results demonstrated that RI inhibits the replication of IAV by activating MAPK/Nrf2/HO-1 signaling pathway, revealing a new mechanism of RI against influenza virus, and providing theoretical basis for clinical treatment of influenza virus.
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Objective: A study was conducted to clarify the anti-influenza virus effect of agricultural, forest and fishery products in Ishikawa Prefecture. Method: The samples were prepared by both hot-water and ethanol extraction. The Madin-Darby canine kidney (MDCK) cells infected with PR8 strain were cultured in Dulbecco's Modified Eagle Medium（DMEM） containing extract for 24 hours and measured virus titer of supernatants by focus-forming reduction assay. Time-of-addition assay was performed to determine the inhibition stage in virus proliferation by the extract. The active ingredients were purified using a solid-phase extraction column (silica gel base C18). Results: We revealed that many products have anti-influenza virus activity. Especially, four products ( Matteuccia struthiopteris, Colocasia esculenta, Sagittaria trifolia, and Eleucine coracana) show strong activity and inhibit several stages in virus proliferation. Conclusion: We performed screening to 46 agricultural, forest and fishery products and found the four products ( Matteuccia struthiopteris, Colocasia esculenta, Sagittaria trifolia, and Eleusine coracana) inhibit virus proliferation strongly. In addition, the isolation and identification of the active ingredients contained in these remain as a future study.
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Three sesquiterpenoids and nine iridoids were isolated from the roots and rhizomes of Valeriana jatamansi by various chromatographic methods. Their structures were identified by physicochemical properties, NMR and MS data. Among them, valeriananoid G (1) was a new patchoulol-type sesquiterpenoid, and compound 3 was isolated from the genus Valeriana for the first time. Compounds 3 and 10 exhibited significant inhibitory effects on nitric oxide production induced by lipopolysaccharide in RAW 264.7 macrophages, with IC50 values of 19.00 and 3.66 μmol·L-1, respectively. In addition, compounds 4, 6 and 12 showed anti-influenza virus activity with IC50 values of 51.75, 51.40 and 102.08 μmol·L-1, respectively.
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Resumen Desde 1982, cada año el Departamento de Inmunizaciones del Ministerio de Salud de Chile lleva a cabo la campaña de vacunación contra influenza junto con las Secretarías Regionales Ministeriales-SEREMI, Servicios de Salud y centros de atención primaria de salud. Con los objetivos de prevenir mortalidad y morbilidad grave en grupos de mayor riesgo y de preservar la integridad de los servicios de salud, hasta el 2020 las campañas de vacunación contra influenza serían las más grandes implementadas en Chile, para dar paso, el 2021, a la vacunación contra SARS-CoV-2. Obedeciendo a cambios demográficos y epidemiológicos locales y acogiendo los avances científicos sobre seguridad e inmunogenicidad de la vacuna, el incremento de las vacunas influenza disponibles en Chile forma parte de la planificación anual de la campaña. El 2020, sin embargo, la Campaña Influenza tuvo que ser re-planificada en curso como consecuencia de la incorporación de nuevos grupos a vacunar según dispuso la modificación de la alerta sanitaria por brote de SARS-CoV-2 del 6 de marzo de 2020. Así, de 6.799.800 de dosis, el Departamento de Inmunizaciones logró en menos de dos meses aumentar la disponibilidad a 8.480.325, y cumplir con el compromiso de garantizar el acceso de los grupos de riesgo al beneficio de la vacunación estatal gratuita.
Abstract In Chile, the Immunization Department of the Ministry of Health has carried out the seasonal influenza vaccination campaign annually since 1982 in collaboration with the national health services, regional health offices, and primary health care centres. With the aim of preventing deaths and serious morbidity in high-risk groups and preserving the integrity of health services, the seasonal influenza campaign had been the largest implemented in Chile until 2020, since in 2021 the vaccination campaign against SARS-CoV-2 is expected to become the largest ever implemented. In response to local demographic and epidemiological changes, and taking into account the new scientific evidence on the safety and immunogenicity of vaccines, the influenza vaccines available in Chile would increase annually as a result of campaign planning. In 2020, the influenza campaign had to be re-planned while in progress due to the addition of new high-risk groups to be vaccinated in accordance with the SARS-CoV-2 pandemic health alert modification of March 6th, 2020. Over the course of three weeks, the Immunization Department managed to increase the doses of available influenza vaccines from 6,799,800 previously agreed upon to 8,480,325 and thus serve high-risk groups, guaranteeing their access to state funded influenza vaccination.
Subject(s)
Humans , Influenza Vaccines , Influenza, Human/prevention & control , Influenza, Human/epidemiology , COVID-19 , Seasons , Chile/epidemiology , Public Health , Mass Vaccination , Immunization Programs , Vaccination Coverage , Pandemics , SARS-CoV-2ABSTRACT
Compound houttuynia mixture belongs to OTC class A medicine, which is made from Houttuynia cordata, Scutellaria baicalensis, Radix Isatidis, Forsythia, and Lonicera. As a kind of compound preparation of traditional Chinese medicine, houttuynia cordata mixture has extensive pharmacological effects, for example, clearing away heat and detoxifying, thus it is used for the sore throat, acute pharyngitis, and tonsillitis with wind-heat syndrome. In this study, the antiviral activity against influenza viruses and the primary mechanism of compound houttuynia mixture was evaluated. The antiviral effect of compound houttuynia mixture was determined by cytopathic effects (CPE), Western blot, quantitive reverse transcription PCR (qRT-PCR), and virus titer assays. The effect of houttuynia mixture on the replication cycle of influenza virus was evaluated by time-of-addition assay. In conclusion, the results showed that the compound houttuynia mixture had a broad-spectrum effect against influenza virus, including the international common influenza virus strains, the drug-resistant strains and the highly pathogenic avian influenza viruses H5N1 and H7N9. It mainly impairs the early stage of the viral replication.
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Objective: To investigate the iridoids from the roots of Valerianajatamansi and their anti-influenza virus activity. Methods: The compounds were isolated and purified over several chromatographic methods, such as silica gel, Sephadex LH-20, HPLC and so on. Their structures were identified by the analysis of their physicochemical properties and NMR data. Their anti-influenza virus activity was evaluated by A/WSN/33/2009 (H1N1) infected MDCK cells. Results: Twenty known iridoids (1-20) were isolated from the EtOAc-soluble fraction of 95% EtOH extract of V. jatamansi, and their structures were identified as baldrinal (1), 11-methoxyviburtinal (2), desacylbaldrinal (3), isovaltrate (4), deacetylisovaltrate (5), 10-isovaleroxy-valtrathydrin (6), jatamanvaltrate Q (7), valeriandoid F (8), isovaltrate acetoxyhydrin (9), jatamanvaltrate K (10), rupesin B (11), patriscadoid II (12), jatamanvaltrate W (13), patriscadoid I (14), valeriandoid D (15), valjatrate E (16), jatamanin C (17), (1S,3R,5S,7S,8S,9S)-1-methoxy-7-hydroxy-8-methyl-3,8-epoxy-Δ4,11-dihyronepetane (18), (3S,4S,5S,7S,8S,9S)-3,8-ethoxy-7-dihydroxy-4,8-dimethylperhydrocyclopenta[c]pyran (19) and 8,9-didehydro-7-hydroxy-dolichodial (20). Conclusion: Compounds 5, 9, 12, 14, and 20are isolated from V. jatamansi for the first time. Furthermore, compounds 4 and 9 exhibit anti-influenza A virus activity with IC50 values of 85.45 and 19.26 μmol/L.
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Seven indole alkaloid glycosides containing a 1'-(4″-hydroxy-3″,5″-dimethoxyphenyl)ethyl unit (-) were isolated from an aqueous extract of leaves (da qing ye). Their structures were determined by spectroscopic data analysis combined with enzymatic hydrolysis as well as comparison of their experimental CD (circular dichroism) and calculated ECD (electrostatic circular dichroism) spectra. Based on analysis of and/or Cotton effect (CE) data of -, two simple roles to assign location and/or configuration of -glycopyranosyloxy and 1'-(phenyl)ethyl units in the indole alkaloid glycosides are proposed. Stereoselectivity in plausible biosynthetic pathways of - is discussed. Compounds and and their mixture in a 3:2 ratio showed activity against KCNQ2 in CHO cells. The mixture of and (3:2) exhibited antiviral activity against influenza virus H1N1 PR8 with IC 64.7 μmol/L (ribavirin, IC 54.3 μmol/L), however, the individual or was inactive. Preliminary structure-activity relationships were observed.
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Pandemic influenza is an acute respiratory infectious disease caused by influenza virus infection, which has the features of high incidence, widespread prevalence, and strong variability. For the prevention and treatment of influenza, Chinese materia medica (CMM) has obvious effects, relatively less toxic side effects, and it is popular and cheap, etc. Many scholars demonstrated the critical roles and mechanisms of CMM using the experiments of CMM against influenza virus. With investigating related literatures in recent years, this article summarizes the anti-influenza activities and mechanisms of actions of CMM, mainly the single herb and compound prescription, in order to provide idea and theoretical basis for future anti-influenza research.
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Influenza is a severe respiratory infectious disease caused by influenza viruses. Due to the widespread prevalence, high morbidity and high mutation rate of influenza viruses, current anti-influenza drugs are not efficient and abundant. Development of novel anti-influenza virus agents is necessary and urgent nowadays. It is meaningful to investigate novel anti-influenza virus agents from traditional Chinese medicines, which is a great heritage and invaluable source for drug development. Though it is difficult to describe the mechanisms of traditional Chinese medicines clearly and comprehensively because of their characteristics of "multiple components and multiple targets", with more in-depth studies, many chemical constituents and action mechanisms of traditional Chinese medicines have been gradually reported nowadays. Most Chinese medicinal herbs could indirectly suppress influenza viruses and alleviate inflammation response via the regulation of cellular immune function of the host. However, studies on the traditional Chinese medicines that directly act on and target the influenza viruses are more complicated. Some of the traditional Chinese prescriptions, single traditional Chinese medicines and isolated compounds as well as their targets for the direct anti-influenza virus effects have been reported, including the familiar targets of hemagglutinin, neuraminidase, RNA polymerase, nucleoprotein complex and viral RNA, etc. This review summarizes the traditional Chinese prescriptions, single traditional Chinese medicines and isolated compounds, which show direct anti-influenza virus effects, in terms of their targets, so as to provide a reference for future studies.
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Influenza virus,as the root cause of public health problems,is mainly transmitted by aerosols with high infectivity and high mortality,which seriously endangers human health.Moreover,influenza viruses mutate rapidly,and existing drugs are constantly appearing resistant,it is urgent to develop new anti-influenza drugs.Now,the anti-influenza drugs with different targets from the 2 aspects of viral targets and host targets are introduces,and focus on the research progress of new anti-influenza drugs.
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This paper aimed to investigate the anti-influenza virus activity of the genus Paeonia, screen potential anti-influenza virus compounds and predict targets of anti-influenza virus to explore the mechanism of anti-influenza virus activity. First of all, a total of 301 compounds of the genus Paeonia were summarized from the literatures in recent ten years. The candidate active ingredients from the genus Paeonia were identified by database such as PubChem and Chemical Book. The ligands were constructed by ChemDraw, Avogadro and Discovery Studio Visualizer. Secondly, 23 potential anti-influenza virus targets were developed by combining the target database and the literatures. Uniprot database was used to find the anti-influenza virus targets, and RCSB was used to identify targets associated with anti-influenza virus activity as docked receptor proteins. QuickVina 2.0 software was used for molecular docking. Finally, the Cytoscape 3.5.1 software was used to map the potential activity compounds of the genus Paeonia against influenza virus and the anti-influenza virus target network. Uniprot online database was used to analyze the target GO enrichment and KEGG metabolic pathways. The results showed that 74 compounds of the genus Paeonia had anti-influenza virus effect and 18 potential anti-influenza virus targets were screened. GO analysis concluded that the mechanism of the genus Paeonia anti-influenza virus is consistent with the mechanism of NA anti-influenza virus in order to stop the sprouting, dispersion and diffusion of virus and reduce the ability of virus to infect, so that the infection can be restricted so as to achieve the anti-influenza virus effect.
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Anti-influenza Chinese herbal medicines (anti-flu CHMs) have advantages in preventing and treating influenza virus infection. Despite various data on antiviral activities of some anti-flu CHMs have been reported, most of them could not be compared using the standard evaluation methods for antiviral activity. This situation poses an obstacle to a wide application of anti-flu CHMs. Thus, it was necessary to develop an evaluation method to estimate antiviral activities of anti-flu CHMs. In the present study, we searched for anti-flu CHMs, based on clinic usage, to select study objects from commonly-used patented anti-flu Chinese medicines. Then, a neuraminidase-based bioassay, optimized and verified by HPLC method by our research group, was adopted to detect antiviral activities of selected 26 anti-flu CHMs. Finally, eight of these herbs, including Coptidis Rhizoma, Isatidis Folium, Lonicerae Flos, Scutellaria Radix, Cyrtomium Rhizome, Houttuynia Cordata, Gardeniae Fructus, and Chrysanthemi Indici Flos, were shown to have strong antiviral activities with half maximal inhibitory concentration (IC) values being 2.02 to 6.78 mg·mL (expressed as raw materials). In contrast, the IC value of positive control peramivir was 0.38 mg·mL. Considering the extract yields of CHMs, the active component in these herbs may have a stronger antiviral activity than peramivir, suggesting that these herbs could be further researched for active compounds. Moreover, the proposed neuraminidase-based bioassay was high-throughput and simple and could be used for evaluation and screening of anti-flu CHMs as well as for their quality control.
Subject(s)
Humans , Antiviral Agents , Chemistry , Pharmacology , Drug Evaluation, Preclinical , Drugs, Chinese Herbal , Chemistry , Pharmacology , Enzyme Inhibitors , Chemistry , Pharmacology , Influenza, Human , Drug Therapy , Virology , Neuraminidase , Metabolism , Orthomyxoviridae , Physiology , Viral Proteins , MetabolismABSTRACT
The seeds of Silybum marianum were extracted by hot water, and the extract was isolated by D101 macroporous resin, MCI resin, MPLC, HPLC, et al. As a result, 7 compounds including tricin 4'-O-[threo-β-guaiacyl-(7″-O-methyl)-glyceryl] ether(1), tricin 4'-O-[erythro-β-guaiacyl-(7″-O-methyl)-glyceryl] ether(2), 5'-methoxyhydnocarpin-D(3),palstatin(4),(8R,7'S,8'R)-5,5'-dimethoxy-7-oxolariciresinol 9'-O-D-xylopyranoside(5), 9-O-D-glucopyranoside(6), and(-)-haplomyrtoside(7) were isolated and identified for the first time. Compounds 1, 3, 4, and 5 exhibited activity against influenza A(H5N1)with IC₅₀ value of 0.65, 0.21, 0.32, and 0.56 μmol•L⁻¹, respectively. Compounds 1, 2, 6, and 7 exhibited cytotoxity against HepG-2 with IC₅₀ value of 0.35, 0.25, 0.53, 0.66 μmol•L⁻¹, respectively.
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Objective: To modify the structure of natural monomeric compound 3-O-caffeoylquinic acid from medicinal plant Pandanus tectorius, and evaluate the anti-influenza virus activity of the derivatives. Methods: Applying 3-O-caffeoylquinic acid as material, the target compounds were prepared by three routes and evaluated for their anti-influenza virus effects by MDCK cells in vitro. Results: Thirteen caffeoylquinic acid derivatives B1-B13 were synthesized. The structures of the target compounds were identified by spectrum. Pharmacological results showed that the compounds B4, B6, and B10 had the different potencial inhibition on the replication of influenza virus in cells. Conclusion: The new compounds B2 and B4-B13 which show the potential biological activity of anti-influenza virus, have not been reported in any literatures and are worth studying further.
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During a search for neuraminidase inhibitors derived from medicinal fungi, we found that the fermentation broth of Phellinus linteus exhibited potent neuraminidase inhibitory activity. Through bioassay-guided fractionation, two active compounds were purified from the ethyl acetate-soluble portion of the fermentation broth of P. linteus. These structures were identified as inotilone (1) and 4-(3,4-dihydroxyphenyl)-3-buten-2-one (2) by spectroscopic methods. Compounds 1 and 2 inhibited H1N1 neuraminidase activity with IC50 values of 29.1 and 125.6 microM, respectively, in a dose-dependent manner. They also exhibited an antiviral effect in a viral cytopathic effect reduction assay using MDCK cells. These results suggest that compounds 1 and 2 from the culture broth of P. linteus would be good candidates for the prevention and therapeutic strategies towards viral infections.
Subject(s)
Cytopathogenic Effect, Viral , Fermentation , Fungi , Inhibitory Concentration 50 , Madin Darby Canine Kidney Cells , NeuraminidaseABSTRACT
METHODS: HPLC method was used to study the stability of sixteen batches of oseltamivir phosphate capsules. Phenomenex C8 (2) column was used with UV detection at 207 nm, and the mobile phase consisted of phosphoric buffer (0.05 mol•L-1 KH2PO4), methanol and acetonitrile (620:135:245), the flow rate was 1.0 mL•min-1, and the column oven was maintained at 50°C. The contents of impurities before and after storage and in accelerated condition were tracked.
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Patent documentation is a kind of high-value scientific literature, which has caught the attention of more and more scholars. In this paper, the World Traditional Medicine Patent Database (WTMPD) was used to retrieve patents of the traditional medicines used in the treatment and prevention of influenza worldwide in the past 30 years. A total of 2 423 patents were further screened by a series of processes. Finally, multi-angle analysis was carried on the dataset to form a patent analysis report on traditional anti-flu drugs. From the analysis, we found that China had a rapid increase in the number of patent applications, which was in the leading role in the world, though the number of PCT applicant from China is relatively low. A large amount of applicants from the USA, Japan, and Korea have entered into China. Pharmaceutical company is the core group of patent applicant, who had applied a lot of quality patent about their products to protect their commercial interests. Honeysuckle, licorice, isatis root, forsythia and skullcap are five kinds of herbs, which have been most frequently used in anti-influenza patents.
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Commercial Oregano oils with high concentrations of carvacrol have been vigorously promoted as antiviral agents effective against colds and ‘flu, including the pandemic H1N1 virus. However there seems to be no evidence to support these claims. Furthermore, since carvacrol itself is known to be toxic, so-called “carrier oils”, such as olive oil, have been included in formulations to ameliorate the potential toxic effects. We compared the antiinfluenza virus activity of several preparations, with and without “carriers”, and pure olive oil and carvacrol, by means of quantitative assays for H1N1 influenza virus, and for cytotoxicity in human lung epithelial cells. A range of concentrations was evaluated, including those relevant to consumer applications. All five Oregano oils showed significant antiviral activity, as did olive oil by itself, although their potencies were not comparable to a standardized preparation of Echinacea purpurea. Carvacrol was also very active, but it was also strongly cytotoxic. In addition all the Oregano oils were more cytotoxic than Echinacea purpurea. Thus certain commercial Oregano oils do possess anti-influenza virus activities, although these are less than a potent standardized Echinacea preparation, and furthermore the toxicity of the oils to lung epithelial cells, at doses relevant to consumer applications, is a limiting factor in their usefulness for oral applications.
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We conducted this open study to evaluate the immunogenicity and safety of the inactivated influenza vaccine, Imovax Gripe® in 154 children between 6 and 36 months of age at high risk of influenza- related complications, and in a reference group of 64 healthy children. The study was conducted over two flu seasons, in which the vaccine contained the same A strains but different B strains. The results for the A/H3N2 and A/H1N1 strains from the two flu seasons were pooled, but those for the B strains were not. Anti-hemagglutinin (HA) antibody titers were determined before, and one month after each vaccination, and safety was evaluated based on diary card reporting any adverse event observed, either included or not in the list of "solicited events". Within each group of vaccines, the seroconversion rates, seroprotection rates, and ratio of post- to prevaccination geometric mean titers (GMTR) for the A/H3N2 and the A/H1N1 strains fulfilled all requirements of the criteria of the European Union Committee for Proprietary Medicinal Products (CPMP). The immune responses in high-risk and in healthy children were similar, and consistent with those observed in previous studies conducted in healthy children. The vaccine was equally well tolerated by all study groups. Reactogenicity was low and similar in both high-risk and healthy children. Overall from 9.5% to 15.4% of at-risk children and 12% of healthy children reported a solicited local reaction; 23.0 to 28.8% of high-risk and 25.3% of healthy children reported a solicited systemic reaction. The study results provide support for vaccination of children at high-risk of influenza related complications.
Se realizó un estudio clínico abierto para evaluar la inmunogenícidad y la seguridad de la vacuna inactivada anti-influenza, Imovax Gripe®, en 154 niños entre 6 y 36 meses de edad con alto riesgo de complicaciones ligadas a la influenza, y en un grupo de referencia de 64 niños sanos. El estudio fue conducido en dos temporadas de gripe, durante las cuales la vacuna utilizada contenia las mismas cepas A pero diferentes cepas B. Los resultados para las cepas A/H3N2 y A/H1N1 de las dos temporadas de gripe fueron combinados ( pool de datos), pero no los de las cepas B. Los títulos de anticuerpos anti-hemaglutinina (HA) fueron determinados inmediatamente antes y un mes despues de cada vacunación, y la seguridad o tolerancia fue evaluada según la información de efectos adversos notificados, en cartillas para llenado diario, que incluían todos los eventos, figuraran o no en la lista de los "eventos solicitados". En cada grupo, las tasas de seroconversion y de seroprotección, y la razón de la media geométrica de títulos post-/ pre-vacunación (GMTR) para las cepas A/H3N2 y A/H1N1 cumplieron con todos los requisitos del Comité de Especialidades Farmacéuticas (CPMP) de la Unión Europea. Las respuestas inmunes fueron similares en los niños con alto riesgo y en los sanos, y consistentes con los resultados observados en los estudios anteriores en los niños sanos. La vacuna fue bien tolerada y la reactogenicidad fue baja y similar en los dos grupos de niños estudiados. Las reacciones locales listadas en la solicitud, fueron observadas en el 9.5 a 15.4% y en el 12% de niños con alto riego y sanos respectivamente; mientras que los síntomas sistémicos solicitados fueron observados en el 23.0 a 28.8% y el 25.3% de niños respectivamente. Los resultados de este estudio proveen informatión adicional a favor de la vacunación de niños con alto riesgo de complicaciones relacionadas con influenza.
Subject(s)
Humans , Male , Female , Infant , Child, Preschool , Antibodies, Viral/immunology , Hemagglutinins, Viral/immunology , Influenza A virus/immunology , Influenza Vaccines/immunology , Influenza, Human/immunology , Respiratory Tract Diseases/immunology , Antibodies, Viral/blood , Confidence Intervals , Costa Rica , Hemagglutinin Glycoproteins, Influenza Virus/immunology , Immunization, Secondary , Influenza A Virus, H1N1 Subtype/immunology , /immunology , Influenza Vaccines/administration & dosage , Influenza Vaccines/adverse effects , Influenza, Human/complications , Influenza, Human/prevention & control , Risk Factors , Respiratory Tract Diseases/prevention & control , Vaccination , Vaccines, InactivatedABSTRACT
Given that highly active antiretroviral therapy (HAART) has been demonstrated useful to restore immune competence in type-1 human immunodeficiency virus (HIV-1)-infected subjects, we evaluated the specific antibody response to influenza vaccine in a cohort of HIV-1-infected children on HAART so as to analyze the quality of this immune response in patients under antiretroviral therapy. Sixteen HIV-1-infected children and 10 HIV-1 seronegative controls were immunized with a commercially available trivalent inactivated influenza vaccine containing the strains A/H1N1, A/H3N2, and B. Serum hemagglutinin inhibition (HI) antibody titers were determined for the three viral strains at the time of vaccination and 1 month later. Immunization induced a significantly increased humoral response against the three influenza virus strains in controls, and only against A/H3N2 in HIV-1-infected children. The comparison of post-vaccination HI titers between HIV-1+ patients and HIV-1 negative controls showed significantly higher HI titers against the three strains in controls. In addition, post vaccination protective HI titers (defined as equal to or higher than 1:40) against the strains A/H3N2 and B were observed in a lower proportion of HIV-1+ children than in controls, while a similar proportion of individuals from each group achieved protective HI titers against the A/H1N1 strain. The CD4+ T cell count, CD4/CD8 T cells ratio, and serum viral load were not affected by influenza virus vaccination when pre- vs post-vaccination values were compared. These findings suggest that despite the fact that HAART is efficient in controlling HIV-1 replication and in increasing CD4+ T cell count in HIV-1-infected children, restoration of immune competence and response to cognate antigens remain incomplete, indicating that additional therapeutic strategies are required to achieve a full reconstitution of immune functions.