Long-term humoral immunogenicity, safety and protective efficacy of inactivated vaccine against COVID-19 (CoviVac) in preclinical studies.

The unprecedented in recent history global COVID-19 pandemic urged the implementation of all existing vaccine platforms to ensure the availability of the vaccines against COVID-19 to every country in the world. Despite the multitude of high-quality papers describing clinical trials of different vaccine products, basic detailed data on general toxicity, reproductive toxicity, immunogenicity, protective efficacy and durability of immune response in animal models are scarce. Here, we developed a ß-propiolactone-inactivated whole virion vaccine CoviVac and assessed its safety, protective efficacy, immunogenicity and stability of the immune response in rodents and non-human primates. The vaccine showed no signs of acute/chronic, reproductive, embryo- and fetotoxicity, or teratogenic effects, as well as no allergenic properties in studied animal species. The vaccine induced stable and robust humoral immune response both in form of specific anti-SARS-CoV-2 IgG and NAbs in mice, Syrian hamsters, and common marmosets. The NAb levels did not decrease significantly over the course of one year. The course of two immunizations protected Syrian hamsters from severe pneumonia upon intranasal challenge with the live virus. Robustness of the vaccine manufacturing process was demonstrated as well. These data encouraged further evaluation of CoviVac in clinical trials.

Development of an Inactivated Vaccine Candidate, BBIBP-CorV, with Potent Protection against SARS-CoV-2.

The coronavirus disease 2019 (COVID-19) pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) threatens global public health. The development of a vaccine is urgently needed for the prevention and control of COVID-19. Here, we report the pilot-scale production of an inactivated SARS-CoV-2 vaccine candidate (BBIBP-CorV) that induces high levels of neutralizing antibodies titers in mice, rats, guinea pigs, rabbits, and nonhuman primates (cynomolgus monkeys and rhesus macaques) to provide protection against SARS-CoV-2. Two-dose immunizations using 2 µg/dose of BBIBP-CorV provided highly efficient protection against SARS-CoV-2 intratracheal challenge in rhesus macaques, without detectable antibody-dependent enhancement of infection. In addition, BBIBP-CorV exhibits efficient productivity and good genetic stability for vaccine manufacture. These results support the further evaluation of BBIBP-CorV in a clinical trial.

Safety of AS03-adjuvanted influenza vaccines: A review of the evidence.

Clinical and post-licensure data have demonstrated that AS03-adjuvanted inactivated split virion vaccines, many with reduced antigen content, are effective against influenza infection. The objective of this review is to provide a comprehensive assessment of the safety of trivalent seasonal, monovalent pre-pandemic and pandemic AS03-adjuvanted influenza vaccines, based on non-clinical, clinical and post-licensure data in various populations. Non-clinical studies on local tolerance, toxicology and safety pharmacology did not raise any safety concerns with AS03 administered alone or combined with various influenza antigens. Data from clinical trials with over 55,000 vaccinated subjects showed that AS03-adjuvanted influenza vaccines were generally well tolerated and displayed an acceptable safety profile, although the power to detect rare events was limited. Approximately 90 million doses of A/H1N1pdm09 pandemic influenza vaccines (Pandemrix and Arepanrix H1N1) were administered worldwide, which contributed post-licensure data to the collective safety data for AS03-adjuvanted influenza vaccines. An association between Pandemrix and narcolepsy was observed during the A/H1N1pdm09 pandemic, for which a role of a CD4 T cell mimicry sequence in the haemagglutinin protein of A/H1N1pdm09 cannot be excluded. Provided that future AS03-adjuvanted influenza vaccines do not contain this putative mimicry sequence, this extensive safety experience supports the further development and use of AS03-adjuvanted inactivated split virion candidate vaccines against seasonal and pandemic influenza infections.

Vaccination strategies against Zika virus.

The epidemic emergence of Zika virus (ZIKV) in 2015-2016 has been associated with congenital malformations and neurological sequela. Current efforts to develop a ZIKV vaccine build on technologies that successfully reduced infection or disease burden against closely related flaviviruses or other RNA viruses. Subunit-based (DNA plasmid and modified mRNA), viral vectored (adeno- and measles viruses) and inactivated viral vaccines are already advancing to clinical trials in humans after successful mouse and non-human primate studies. Among the greatest challenges for the rapid implementation of immunogenic and protective ZIKV vaccines will be addressing the potential for exacerbating Dengue virus infection or causing Guillain-Barré syndrome through production of cross-reactive immunity targeting related viral or host proteins. Here, we review vaccine strategies under development for ZIKV and the issues surrounding their usage.

Immunogenicity and safety of an AS03-adjuvanted H7N1 vaccine in adults 65years of age and older: A phase II, observer-blind, randomized, controlled trial.

BACKGROUND: H7 influenza strains can cause severe and often fatal human infections, especially in the elderly. This phase II, observer-blind, randomized trial (www.ClinicalTrials.gov: NCT01949090) assessed the immunogenicity and safety of a novel AS03-adjuvanted H7N1 vaccine that may serve as a model H7-subtype vaccine. METHODS: 360 adults ≥65years of age in stable health received either 1 of 4 adjuvanted A/mallard/Netherlands/12/2000 split virion vaccine formulations (3.75µg or 7.5µg hemagglutinin adjuvanted with either AS03A or AS03B) or saline placebo, given as a 2-dose series. Immunogenicity was assessed using hemagglutination-inhibition (HI) and microneutralization (MN) assays for the per-protocol cohort, comprising 332 participants at 21days post-each dose, 332 at month 6, and 309 at month 12 (HI assay only). Safety was assessed up to month 12 for all participants who had received ≥1 dose (360 participants). RESULTS: For H7N1 HI antibody assessment at day 42 (21days post-dose 2), seroprotection rates (SPR) in the vaccinated groups were 69.6%-88.7%, seroconversion rates (SCR) 69.6%-88.5%, mean geometric increase (MGI) 11.0-18.9, and HI geometric mean titers (GMTs) 55.0-104.8. These parameters declined by month 6 and month 12. Microneutralization GMTs were 46.2-74.7 in the vaccinated groups at day 42, while vaccine response rate (VRR; proportion with ≥4-fold increase in MN titer) was 46.4%-81.5%. For the cross-reactive H7N9 strain, at day 42, HI GMT were 64.3-201.3, SPR 78.6%-96.3%, SCR 79.3%-96.3%, and MGI 14.1-37.7; MN GMTs were 44.0-85.6, and VRR 46.4-85.2%. The most frequent solicited symptom was injection site pain (41.7%-65.0% of vaccine recipients). In total, 40 participants reported 67 serious adverse events; none were considered causally related to vaccination. CONCLUSIONS: In adults aged ≥65years, the adjuvanted H7N1 vaccine was immunogenic after 2 doses, and had an acceptable safety profile. www.ClinicalTrials.gov: NCT01949090.

Immunogenicity and safety of an AS03-adjuvanted H7N1 vaccine in healthy adults: A phase I/II, observer-blind, randomized, controlled trial.

BACKGROUND: H7 influenza strains have pandemic potential. AS03-adjuvanted H7N1 A/mallard/Netherlands/12/2000 split-virion vaccine formulations were evaluated as model H7-subtype vaccine and tested after H7N9 emerged in China, and caused severe human disease with high mortality. METHODS: In this phase I/II, observer-blind, randomized trial in US and Canada, 420 healthy adults (21-64years) were randomized to receive 1 of 4 H7N1 vaccine formulations (3.75 or 7.5µg hemagglutinin adjuvanted with either AS03A or AS03B), 15µg unadjuvanted H7N1 hemagglutinin, or saline placebo, given as 2-dose series. Immunogenicity was assessed using hemagglutination-inhibition (HI) and microneutralization (MN) assays, at day 42 (21days post-dose 2), month 6, and month 12 (HI only) for the per-protocol cohorts (398, 379 and 368 participants, respectively). Safety is reported up to month 12. RESULTS: Beneficial AS03 adjuvant effect was demonstrated. Committee for Medical Products for Human Use, and Center for Biologics Evaluation and Research (CBER) criteria were met for all adjuvanted formulations at day 42 (H7N1 HI assay); seroprotection (SPR) and seroconversion rates (SCR) were 88.5-94.8%, mean geometric increase (MGI) 19.2-34.9, and geometric mean titers (GMT) 98.3-180.7. Unadjuvanted H7N1 vaccine did not meet CBER criteria. In adjuvanted groups, antibody titers decreased over time; month 12 SPRs and GMTs were low (2.0-18.8% and 8.1-12.2). MN antibodies showed similar kinetics, with titers persisting at higher range than HI at month 6. All adjuvanted groups showed cross-reactivity against H7N9, with HI responses similar to H7N1. The most frequent solicited symptom in adjuvanted groups was injection site pain (71.2-86.7%); grade 3 solicited symptoms were infrequent. Nine participants reported 17 serious adverse events; none were considered causally related to vaccination. CONCLUSIONS: Adjuvanted H7N1 vaccine formulations had an acceptable safety profile and induced an antibody response after 2 doses with cross-reactivity to H7N9. ClinicalTrials.gov: NCT01934127.

A novel preservative-free seasonal influenza vaccine safety and immune response study in the frame of preclinical research.

The paper describes the results of preclinical testing of the preparation "Vaccine allantoic split-virus inactivated against seasonal influenza." Acute toxicity and local irritating effect, anaphylactic reactions to different antigens (vaccine and ovalbumin), delayed-type hypersensitivity to ram erythrocytes, humoral immune response in hemaggtination reaction, immunogenic activity was studied in laboratory animals of various species (mice, rats, guinea pigs). Comparative analysis of the results from testing immunogenic activity of the preparation under study and the commercial influenza vaccines was performed. The preclinical testing has demonstrated safety and immune response of the seasonal split influenza vaccine, so it may be recommended for clinical study on limited contingent of volunteers.

Pre-clinical development of a hydrogen peroxide-inactivated West Nile virus vaccine.

West Nile virus (WNV) is a mosquito-transmitted pathogen with a wide geographical range that can lead to long-term disability and death in some cases. Despite the public health risk posed by WNV, including an estimated 3 million infections in the United States alone, no vaccine is available for use in humans. Here, we present a scaled manufacturing approach for production of a hydrogen peroxide-inactivated whole virion WNV vaccine, termed HydroVax-001WNV. Vaccination resulted in robust virus-specific neutralizing antibody responses and protection against WNV-associated mortality in mice or viremia in rhesus macaques (RM). A GLP-compliant toxicology study performed in rats demonstrated an excellent safety profile with clinical findings limited to minor and transient irritation at the injection site. An in vitro relative potency (IVRP) assay was developed and shown to correlate with in vivo responses following forced degradation studies. Long-term in vivo potency comparisons between the intended storage condition (2-8°C) and a thermally stressed condition (40±2°C) demonstrated no loss in vaccine efficacy or protective immunity over a 6-month span of time. Together, the positive pre-clinical findings regarding immunogenicity, safety, and stability indicate that HydroVax-001WNV is a promising vaccine candidate.

Immunogenicity and Safety of an AS03-Adjuvanted H7N9 Pandemic Influenza Vaccine in a Randomized Trial in Healthy Adults.

BACKGROUND: Almost 700 cases of human infection with avian influenza A/H7N9 have been reported since 2013. Pandemic preparedness strategies include H7N9 vaccine development. METHODS: We evaluated an inactivated H7N9 vaccine in an observer-blind study in healthy adults aged 18-64 years. Participants (420) were randomized to receive 1 of 4 AS03-adjuvanted vaccines (low or medium dose of hemagglutinin with AS03A or AS03B), one nonadjuvanted vaccine, or placebo. The coprimary immunogenicity objective determined whether adjuvanted vaccines elicited an immune response against the vaccine-homologous virus, 21 days after the second vaccine dose per US and European licensure criteria in the per-protocol cohort (n = 389). RESULTS: All adjuvanted vaccines met regulatory acceptance criteria. In groups receiving adjuvanted formulations, seroconversion rates were ≥85.7%, seroprotection rates ≥91.1%, and geometric mean titers ≥92.9% versus 23.2%, 28.6%, and 17.2 for the nonadjuvanted vaccine. The AS03 adjuvant enhanced immune response at antigen-sparing doses. Injection site pain occurred more frequently with adjuvanted vaccines (in ≤98.3% of vaccinees) than with the nonadjuvanted vaccine (40.7%) or placebo (20.0%). None of the 20 serious adverse events reported were related to vaccination. CONCLUSIONS: Two doses of AS03-adjuvanted H7N9 vaccine were well tolerated and induced a robust antibody response at antigen-sparing doses in healthy adults. CLINICAL TRIALS REGISTRATION: NCT01999842.

Immunogenicity and safety of an AS03-adjuvanted H5N1 pandemic influenza vaccine in Korean adults: a phase IV, randomized, open-label, controlled study.

BACKGROUND: AS03-adjuvanted H5N1 pandemic influenza vaccines have been assessed in an extensive clinical development program conducted in North America, Europe, and Asia including children from 6 months of age, adults, and elderly adults. We evaluated AS03-H5N1 in Korean adults 18 through 60 years of age. METHODS: This Phase IV, randomized, study was conducted to assess the immunogenicity, reactogenicity, and safety of two doses (3.75µg of hemagglutinin antigen) of A/Indonesia/5/2005 (H5N1) adjuvanted with AS03 given 21 days apart in Korean adults. Antibody responses were assessed using hemagglutination-inhibition (HI) assays against the vaccine strain and a vaccine-heterologous strain (A/Vietnam/1194/2004) 21 days after the second dose. A control group (safety) received a licensed seasonal inactivated trivalent influenza vaccine (TIV). Reactogenicity was assessed for 7 days after each vaccination, and unsolicited adverse events were assessed for 182 days following vaccination in both study groups (NCT01730378). RESULTS: AS03-H5N1 was immunogenic and elicited robust HI antibody responses with seroconversion rates of 100% for the vaccine strain and 69.1% for the heterologous strain (N=81). HI antibody responses fulfilled the European licensure criteria for immunogenicity (primary endpoint). The incidence of local and systemic solicited adverse events (reactogenicity) was higher with AS03-H5N1 than TIV. There was no apparent difference in the rate of unsolicited adverse events in the AS03-H5N1 and TIV groups. CONCLUSION: The results indicate that AS03-H5N1 vaccine is immunogenic with reactogenicity and safety findings that are consistent with the established profile of AS03-H5N1 vaccine.

AS03B-adjuvanted H5N1 influenza vaccine in children 6 months through 17 years of age: a phase 2/3 randomized, placebo-controlled, observer-blinded trial.

BACKGROUND: This phase 2/3, randomized, placebo-controlled, observer-blinded study assessed the immunogenicity, reactogenicity, and safety of an inactivated, split-virion H5N1 influenza vaccine (A/Indonesia/5/2005) in children aged 6 months through 17 years. METHODS: Children received 2 influenza vaccine doses 21 days apart, each containing 1.9 µg of hemagglutinin and AS03B adjuvant (5.93 mg of α-tocopherol). The randomization ratio was 8:3 for vaccine to placebo, with equal allocation between 3 age strata (6-35 months, 3-8 years, and 9-17 years). Immunogenicity against the vaccine strain was assessed 21 days after the first and second vaccine doses for all vaccinees, at day 182 for half, and at day 385 for the remaining half. Reactogenicity after each dose and safety up to 1 year after vaccination were evaluated. RESULTS: Within each age stratum, the lower limit of the 98.3% confidence interval for the day 42 seroprotection rate was ≥70%, thus fulfilling the US and European licensure criteria. The immune responses elicited by vaccine persisted well above baseline levels for 1 year. The vaccine was more reactogenic than placebo, but no major safety concerns were identified. CONCLUSIONS: AS03B-adjuvanted H5N1 influenza vaccine was immunogenic and showed an acceptable safety profile in all age groups studied. Clinical Trials Registration: NCT01310413.

A phase 1, open-label safety and immunogenicity study of an AS03-adjuvanted trivalent inactivated influenza vaccine in children aged 6 to 35 months.

BACKGROUND:  There is a need for better vaccines and vaccine strategies to reduce the burden of influenza in very young children.   METHODS:  This phase 1, open-label study assessed the reactogenicity, safety, and immunogenicity of an inactivated trivalent influenza vaccine (TIV) containing low doses of hemagglutinin antigen (7.5 µg each strain), adjuvanted with a tocopherol-based oil-in-water emulsion Adjuvant System (AS03). Influenza vaccine-naïve children aged 6-35 months were sequentially enrolled to receive TIV-AS03D (1.48 mg tocopherol) or TIV-AS03C (2.97 mg tocopherol), then a 6-month booster of conventional TIV. The primary endpoint was the incidence of fever (axillary temperature >38 °C) for 7 days post-vaccination. Immune responses were assessed by hemagglutination-inhibition (HI) assay. RESULTS:  Forty children were sequentially enrolled into the TIV-AS03D or the TIV-AS03C group. Fever >38.0 °C was reported in 5/20 (25.0%) and 7/20 (35.0%) children after the first and second doses of TIV-AS03D, respectively, and in 7/20 (35.0%) children after 1 dose of TIV-AS03C; the latter fulfilled the holding rule for safety, and the second dose of TIV-AS03C was cancelled. HI immune responses exceeded adult European licensure criteria for the immunogenicity, and all children had HI antibody titers ≥ 1:40 after 1 dose of TIV booster against booster strains. CONCLUSIONS:  One dose of primary vaccine containing a low dose of antigen and AS03 may be a possible influenza vaccination strategy for young children. The relatively high frequency of fever warrants further investigation, although the generalizability of the findings are uncertain given that many of the children had antibody evidence suggesting recent infection with A(H1N1)pdm09.

Elevated serum anti-phosphatidylcholine IgG antibodies in patients with influenza vaccination-associated optic neuritis.

INTRODUCTION: Because the optic nerve is mainly comprised from phospholipids such as phosphatidylcholine, the association between optic neuritis, anti-phospholipids antibodies and vaccination was examined. SUBJECTS: Two female pediatric patients suddenly presented bilateral optic neuritis after administration of trivalent inactivated influenza vaccine. METHODS: These two patients and another 11 patients with central nervous system demyelinating diseases were examined these anti-phospholipids antibodies. And immune histopathology was examined using serum derived from a patient with optic neuritis. RESULTS: High serum titer of anti-phosphatidylcholine antibody levels were detected during acute phase in patients with optic neuritis. The patient's serum IgG antibodies were found to have stained the capillary endotheliums in the preserved autopsied optic nerve. Patients with optic neuritis had significantly elevated serum levels of anti-phosphatidylcholine antibody in comparison to the other patients without optic neuritis. CONCLUSION: Anti-phosphatidylcholine antibodies may be one of the causes of optic neuritis.

Ginseng diminishes lung disease in mice immunized with formalin-inactivated respiratory syncytial virus after challenge by modulating host immune responses.

Formalin-inactivated respiratory syncytial virus (FI-RSV) immunization is known to cause severe pulmonary inflammatory disease after subsequent RSV infection. Ginseng has been used in humans for thousands of years due to its potential health benefits. We investigated whether ginseng would have immune modulating effects on RSV infection in mice previously immunized with FI-RSV. Oral administration of mice with ginseng increased IgG2a isotype antibody responses to FI-RSV immunization, indicating T-helper type 1 (Th1) immune responses. Ginseng-treated mice that were nonimmunized or previously immunized with FI-RSV showed improved protection against RSV challenge compared with control mice without ginseng treatment. Ginseng-mediated improved clinical outcomes after live RSV infection were evidenced by diminished weight losses, decreased interleukin-4 cytokine production but increased interferon-γ production, modulation of CD3 T-cell populations toward a Th1 response, and reduced inflammatory response. Ginseng-mediated protective host immune modulation against RSV pulmonary inflammation was observed in different strains of wild-type and mutant mice. These results indicate that ginseng can modulate host immune responses to FI-RSV immunization and RSV infection, resulting in protective effects against pulmonary inflammatory disease.

Impact of vitamin D administration on immunogenicity of trivalent inactivated influenza vaccine in previously unvaccinated children.

As vitamin D (VD) has a significant regulatory effect on innate and adaptive immunity, the aim of this prospective, randomized, single-blinded, placebo-controlled study was to measure the impact of VD administration on the immune response to trivalent influenza vaccination (TIV). A total of 116 children (61 males, 52.6%; mean age 3.0 ± 1.0 y) with a history of recurrent acute otitis media (AOM), who had not been previously vaccinated against influenza, were randomized to receive daily VD 1,000 IU or placebo by mouth for four months. All of them received two doses of TIV (Fluarix, GlaxoSmithKline Biologicals) one month apart, with the first dose administered when VD supplementation was started. There was no difference in seroconversion or seroprotection rates, or antibody titers, in relation to any of the three influenza vaccine antigens between the VD and placebo groups, independently of baseline and post-treatment VD levels. The safety profile was also similar in the two groups. These data indicate that the daily administration of VD 1,000 IU for four months from the time of the injection of the first dose of TIV does not significantly modify the antibody response evoked by influenza vaccine.

The Madin-Darby canine kidney cell culture derived influenza A/H5N1 vaccine: a phase I trial in Taiwan.

BACKGROUND: Avian H5N1 influenza has caused human infections globally and has a high mortality rate. Rapid production of effective vaccines is needed. METHODS: A phase 1, randomized, observer-blinded clinical trial was conducted to examine the safety and immunogenicity of an inactivated whole virion vaccine against the influenza A/H5N1 virus produced from the Madin-Darby canine kidney (MDCK) cell line. Participants were randomized to four groups and administered two intramuscular doses of vaccine containing 3 µg hemagglutinin (HA), 3 µg HA with 300 µg aluminum phosphate (AlPO4), 6 µg HA, and 6 µg HA with 300 µg AlPO4, respectively, at two visits, 21 days apart. Serum hemagglutination inhibition (HAI) and neutralizing antibody levels were determined at baseline and on Days 21 and 42. RESULTS: Sixty healthy individuals were enrolled. The neutralization assay showed a significant immune response in the 6 µg with ALPO4 group on Day 42 compared to pre-vaccination levels (11.32±9.77 vs. 4.00±0, p=0.02). The adjuvant effect in neutralization assay was also significant on Day 42 in the 6 µg group (4.52±1.94 without adjuvant vs. 11.32±9.77 with adjuvant, p=0.02). HAI assay also showed an aluminum adjuvant-induced increasing trend in HAI geometric mean titer on Day 42 in the 3 µg and 6 µg groups (6.02 versus 8.20, p=0.05 and 5.74 versus 8.21, p=0.14). The most frequent adverse event was local pain (20% to 60%). There were no vaccine-related severe adverse effects. CONCLUSION: MDCK cell line-derived H5N1 vaccine was well tolerated. It is necessary to investigate further the immunogenicity of higher antigen doses and the role of aluminum adjuvant in augmenting the effect of the vaccine.

Safety and immunogenicity of 2010-2011 H1N12009-containing trivalent inactivated influenza vaccine in children 12-59 months of age previously given AS03-adjuvanted H1N12009 pandemic vaccine: a PHAC/CIHR Influenza Research Network (PCIRN) study.

BACKGROUND: Concern arose in 2010 that reactogenicity, particularly febrile seizures, to influenza A/H1N1-containing 2010-2011 trivalent seasonal inactivated influenza vaccine (TIV) could occur in young children who had been previously immunized and/or infected with the pandemic strain. We conducted a pre-season study of 2010-2011 TIV safety and immunogenicity in children 12-59 months of age to inform public health decision making. METHODS: Children immunized with 1 or 2 doses of the pandemic vaccine, with or without the 2009-10 TIV, received 1 or 2 doses of 2010-11 TIV in an observational, multicentre Canadian study. Standard safety monitoring was enhanced by a telephone call at ~24 h post-TIV when adverse events were expected to peak. Summary safety reports were rapidly reported to public health before the launch of public programs. TIV immunogenicity was assessed day 0, and 21 days after final vaccination. Clinical Trials Registration NCT01180621. RESULTS: Among 207 children, a general adverse event was reported by 60.9% of children post-dose one and by 58.3% post-dose two. Only severe fever (>38.5°C) was more common in two-dose compared to one dose recipients (16.7%, n=4 v. 1.0%, n=2). At baseline 99.0% of participants had A/H1N1 hemagglutinin inhibition (HAI) titers ≥10, and 85.5% had a protective titer of ≥40 (95% CI 80.0, 90.0). Baseline geometric mean titers (GMT) were higher in recipients of a 2-dose schedule of pandemic vaccine compared to one-dose recipients: 153.1 (95% CI 126.2, 185.7) v. 78.8 ((58.1, 106.8, p<0.001). At 21 days, all regulatory criteria for influenza vaccine immunogenicity were exceeded for A/H1N1 and H3N2, but responses to the B antigen were poor. No correlations between reactogenicity and either baseline high influenza titers or serologic response to revaccination were evident. CONCLUSIONS: Infants and toddlers who received AS03-adjuvanted A/H1N1 2009 vaccine up to 11 months earlier retained high titers in the subsequent season but re-exposure to A/H1N1 2009 antigen in TIV resulted in no unusual adverse effects and 100% were sero-protected for A/H1N1 after receipt of the 2010-11 TIV.

Predictors of immune response and reactogenicity to AS03B-adjuvanted split virion and non-adjuvanted whole virion H1N1 (2009) pandemic influenza vaccines.

In 2009, 943 children aged 6 months to 10 years were randomised to receive two doses of an oil-in water AS03B-adjuvanted split virion or a non-adjuvanted whole virion H1N1 (2009) vaccine. The large numbers allowed investigation of possible predictors of immune response and reactogenicity. We used regression analysis to examine the effect of variables including past receipt of seasonal vaccine, antipyretics post-vaccination, interval between doses and pre-existing antibodies to H1N1 (2009) on immunogenicity. We also examined the relationship between immunogenicity and reactogenicity and whether prior infection or underlying conditions affected reactogenicity. For both vaccines, haemagglutination-inhibition titres were 60% higher in children with fever ≥38 °C after vaccination and 29% lower in those previously given seasonal vaccine. Early use of antipyretics did not affect immunogenicity. Post-vaccination titres were higher with longer intervals between doses and in those with evidence of prior infection, but reactogenicity in the latter was unaffected. In the adjuvanted vaccine group, reactions were more common in children with atopy. Both vaccines were safe and immunogenic in those with prior infection. Reduction in the interval between doses for earlier protection would be at the cost of reduced immunogenicity. The effect of seasonal vaccine on immunogenicity merits further investigation.

Monovalent inactivated split-virion AS03-adjuvanted pandemic influenza A (H1N1) vaccine.

The first cases of pandemic influenza A (H1N1) 2009 infection were seen in Mexico in March 2009. Since then, it is thought to have been responsible for at least 18,337 deaths globally. Owing to the young age of fatalities, there have been an estimated 2 million years of life lost, which is comparable to the previous pandemics of 1957 and 1968. In this article, we consider the available data on a monovalent inactivated split-virion AS03-adjuvanted pandemic influenza A (H1N1) vaccine, Pandemrix™ (GlaxoSmithKline, Rixensart, Belgium). At present, Pandemrix appears to be highly immunogenic in all age groups, including children and infants under 3 years of age, with an acceptable safety profile in the context of an influenza pandemic. However, owing to the novel adjuvant, further studies on the safety, immunogenicity and vaccine effectiveness of Pandemrix together with robust post-marketing surveillance are required.

[Results of preclinical study of inactivated subunit adsorbed monovalent influenza vaccine "PANDEFLU"].

AIM: To perform preclinical study of subunit monovalent adsorbed inactivated influenza vaccine "PANDEFLU" [strains A/California/7/2009 (HIN1)v]. MATERIALS AND METHODS: Preclinical study of acute toxicity on experimental animals (assessment of vaccine's toxic effects on organs and body systems; pathomorphologic study of organs and tissues after administration of the vaccine; assessment of its influence on hematologic indicators). RESULTS: It was shown that administration of the vaccine did not lead to death of animals as well as to decrease of body mass or development of pathologic, focal sclerotic changes in parenchymal cells and visceral stroma; the vaccine did not negatively change hematologic and biochemical indicators of blood. Results of necropsy and histological study after acute administration of the vaccine in standard dose did not lead to irritation, inflammation or destruction of tissues in the place of inoculation. The vaccine was apyrogenic and did not have local irritating and allergenic effects. Status of animals after acute inoculation of the vaccine demonstrated its good tolerability and safety in doses exceeding standard human doses more than tenfold. CONCLUSION. Performed research demonstrated absence of contraindications for conduction of clinical trials of "PANDEFLU" vaccine on limited contingent of volunteers.