Scalable live-attenuated SARS-CoV-2 vaccine candidate demonstrates preclinical safety and efficacy.

Successfully combating the COVID-19 pandemic depends on mass vaccination with suitable vaccines to achieve herd immunity. Here, we describe COVI-VAC, the only live attenuated severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccine currently in clinical development. COVI-VAC was developed by recoding a segment of the viral spike protein with synonymous suboptimal codon pairs (codon-pair deoptimization), thereby introducing 283 silent (point) mutations. In addition, the furin cleavage site within the spike protein was deleted from the viral genome for added safety of the vaccine strain. Except for the furin cleavage site deletion, the COVI-VAC and parental SARS-CoV-2 amino acid sequences are identical, ensuring that all viral proteins can engage with the host immune system of vaccine recipients. COVI-VAC was temperature sensitive in vitro yet grew robustly (>107 plaque forming units/mL) at the permissive temperature. Tissue viral loads were consistently lower, lung pathology milder, and weight loss reduced in Syrian golden hamsters (Mesocricetus auratus) vaccinated intranasally with COVI-VAC compared to those inoculated with wild-type (WT) virus. COVI-VAC inoculation generated spike IgG antibody levels and plaque reduction neutralization titers similar to those in hamsters inoculated with WT virus. Upon challenge with WT virus, COVI-VAC vaccination reduced lung challenge viral titers, resulted in undetectable virus in the brain, and protected hamsters from almost all SARS-CoV-2-associated weight loss. Highly attenuated COVI-VAC is protective at a single intranasal dose in a relevant in vivo model. This, coupled with its large-scale manufacturing potential, supports its potential use in mass vaccination programs.

Safety and Immunogenicity of a Novel Intranasal Influenza Vaccine (NasoVAX): A Phase 2 Randomized, Controlled Trial.

Annual influenza vaccination greatly reduces morbidity and mortality, but effectiveness remains sub-optimal. Weaknesses of current vaccines include low effectiveness against mismatched strains, lack of mucosal and other effective tissue-resident immune responses, weak cellular immune responses, and insufficiently durable immune responses. The safety and immunogenicity of NasoVAX, a monovalent intranasal influenza vaccine based on a replication-deficient adenovirus type 5 platform, were evaluated in a placebo-controlled single ascending-dose study. Sixty healthy adults (18-49 years) received a single intranasal dose of 1×109 viral particles (vp), 1 × 1010 vp, or 1 × 1011 vp of NasoVAX or placebo. NasoVAX was well-tolerated and elicited robust influenza-specific systemic and mucosal immune responses. The highest NasoVAX dose and the approved Fluzone® influenza vaccine elicited comparable hemagglutination inhibition (HAI) geometric mean titers (152.8 vs. 293.4) and microneutralization (MN) geometric mean titers (142.5 vs. 162.8), with NasoVAX HAI titers maintained more than 1-year on average following a single dose. Hemagglutinin-specific T cells responses were also documented in peripheral mononuclear cell (PBMC) preparations. Consistent with the intranasal route of administration, NasoVAX elicited antigen-specific mucosal IgA responses in the nasopharyngeal cavity with an increase of approximately 2-fold over baseline GMT at the mid- and high-doses. In summary, NasoVAX appeared safe and elicited a broad immune response, including humoral, cellular, and mucosal immunity, with no impact of baseline anti-adenovirus antibody at the most immunogenic dose.

A codon-pair deoptimized live-attenuated vaccine against respiratory syncytial virus is immunogenic and efficacious in non-human primates.

Despite a critical need for a respiratory syncytial virus (RSV) vaccine and decades of development efforts, a vaccine to protect infants, elderly, and other at-risk populations from RSV infection remains elusive. We have previously generated a new, live-attenuated vaccine candidate against RSV using rational, computer-aided gene design and chemical synthesis through a process termed viral gene "deoptimization." In this study, we assessed the attenuation, immunogenicity, and efficacy of this synthetic, live-attenuated RSV vaccine candidate, RSV-MinL4.0, in African Green Monkeys. RSV-MinL4.0 was produced under good-manufacturing-practice (GMP) in Vero cells. Vaccination with RSV-MinL4.0 resulted in minimal virus shedding after vaccination, generation of robust humoral and cellular immune responses (despite the presence of baseline RSV neutralizing antibodies in one animal) that were comparable to a wildtype infection, and protection from virus shedding post-challenge with wildtype RSV. These findings demonstrate the promise of RSV-MinL4.0 as a live-attenuated vaccine which will undergo clinical trials to test its ability to safely and effectively protect pediatric and elderly populations from infection with RSV.

Therapeutic HSV-2 vaccine decreases recurrent virus shedding and recurrent genital herpes disease.

BACKGROUND: Genital herpes simplex virus (HSV) type 2 is a common persistent infection that frequently reactivates to cause recurrent lesions and recurrent viral shedding which is incompletely controlled by antiviral therapy. GEN-003 is a candidate therapeutic vaccine containing 2 HSV-2 proteins, gD2 and ICP4, and Matrix-M2 adjuvant (M2). METHODS: HSV-2 seropositive persons with genital herpes were randomized into three dose cohorts of Gen-003 (60 µg antigen/50 µg M2, 60 µg/75 µg M2 or Placebo). Three intramuscular doses 21 days apart of GEN-003 or placebo were administered. Participants obtained genital area swabs twice-daily for HSV-2 detection and monitored genital lesions for 12 months. The rates of virus shedding and lesion rates before vaccination were compared to 3 defined periods after vaccination; Days 43-71, Month 6 and Month 12. RESULTS: GEN-003 at a dose of 60 µg each antigen/50 µg M2 reduced HSV shedding immediately after dosing with a rate ratio of 0.58, compared to 0.75 for the GEN-003 60 µg/75 µg M2 and 1.06 for placebo. Lesion rates, recurrence rates, and duration of recurrences were also reduced. Reactogenicity was higher with the 75 µg M2 dose than the 50 µg M2 dose, specifically for pain, tenderness, malaise and fatigue. Antibody and cellular immune responses were stimulated by both doses and persisted to 12 months. CONCLUSIONS: GEN-003 vaccine manufactured with a scalable process gave results similar to those observed in prior clinical trials. GEN-003 had an acceptable safety profile and stimulated both humoral and cellular immune responses. The 60 µg antigen/50 µg M2 provided the maximal effect on virologic and clinical measures and warrants further development. (Funded by Genocea; ClinicalTrials.gov number NCT02515175).

Effects of Different Doses of GEN-003, a Therapeutic Vaccine for Genital Herpes Simplex Virus-2, on Viral Shedding and Lesions: Results of a Randomized Placebo-Controlled Trial.

Background: GEN-003 is a candidate therapeutic vaccine for genital herpes simplex virus type 2 (HSV-2). We compared virologic and clinical impact of varying GEN-003 doses. Methods: Adults with symptomatic HSV-2 received placebo or GEN-003 (30 or 60 µg antigen with 25, 50, or 75 µg adjuvant). Viral shedding and lesion rates before vaccination were compared with those measured immediately after vaccination, then at weeks 29-33 and 53-57 after last dose. Results: Compared with baseline shedding rates, the rate ratios for viral shedding immediately after treatment were as follows: 0.82 (95% confidence interval [CI], 0.49-1.36), 30 µg antigen/25 µg adjuvant (30/25) dose; 0.64 (95% CI, 0.45-0.92), 30/50 dose; 0.63 (95% CI, 0.37-1.10), 30/75 dose; 0.56 (95% CI, 0.36-0.88), 60/25 dose; 0.58 (95% CI, 0.38-0.89), 60/50 dose; 0.45 (95% CI, 0.16-0.79), 60/75 dose; and 0.98 (95% CI, 0.76-1.26), placebo. Lesion rate reductions by GEN-003 ranged from 31% to 69%, but lesion rates also decreased among placebo recipients (62%). Reductions in shedding and lesion rate were durable for 12 months for the 60 µg antigen plus 50 or 75 µg adjuvant groups. No serious adverse events occurred with vaccination. Conclusions: The most efficacious vaccine combinations for GEN-003 were the 60 µg/50 µg and 60 µg/75 µg doses.

Therapeutic Vaccine for Genital Herpes Simplex Virus-2 Infection: Findings From a Randomized Trial.

Background: Genital herpes simplex virus type 2 (HSV-2) infection causes recurrent lesions and frequent viral shedding. GEN-003 is a candidate therapeutic vaccine containing HSV-2 gD2∆TMR and ICP4.2, and Matrix-M2 adjuvant. Methods: Persons with genital herpes were randomized into 3 dose cohorts to receive 3 intramuscular doses 21 days apart of 10 µg, 30 µg, or 100 µg of GEN-003, antigens without adjuvant, or placebo. Participants obtained genital swab specimens twice daily for HSV-2 detection and monitored genital lesions for 28-day periods at baseline and at intervals after the last dose. Results: One hundred and thirty-four persons received all 3 doses. Reactogenicity was associated with adjuvant but not with antigen dose or dose number. No serious adverse events were attributed to GEN-003. Compared with baseline, genital HSV-2 shedding rates immediately after dosing were reduced with GEN-003 (from 13.4% to 6.4% for 30 µg [P < .001] and from 15.0% to 10.3% for 100 µg [P < .001]). Lesion rates were also significantly (P < .01) reduced immediately following immunization with 30 µg or 100 µg of GEN-003. GEN-003 elicited increases in antigen binding, virus neutralizing antibody, and T-cell responses. Conclusions: GEN-003 had an acceptable safety profile and stimulated humoral and cellular immune responses. GEN-003 at doses of 30 µg and 100 µg reduced genital HSV shedding and lesion rates. Clinical Trials Registration: NCT01667341 (funded by Genocea).

Ensuring participant safety and trial integrity with clinical trials oversight.

Clinical trial oversight is a critical element that ensures the protection of research participants and integrity of the data collected. The trial sponsor, a local Institutional Review Board, and independent monitoring committees all contribute with complementary but overlapping responsibilities. Consistency among these groups is essential for the smooth conduct of a clinical trial but may be challenging in resource-limited settings (RLS). Capacity building and training for RLS may improve clinical trials oversight and ultimately medical management. In this article, we review the components necessary for optimal clinical trial oversight and the issues that arise in the RLS, with some suggested strategies for improvement.

High dose atorvastatin decreases cellular markers of immune activation without affecting HIV-1 RNA levels: results of a double-blind randomized placebo controlled clinical trial.

BACKGROUND: 3-hydroxy-3-methyl-glutaryl-coenzyme A reductase inhibitors (statins) exhibit antiviral activity against human immunodeficiency virus type 1 (HIV-1) in vitro and may modulate the immune response to HIV infection. Studies evaluating the antiviral activity of statins have yielded conflicting results. METHODS: We conducted a randomized, double-blind, placebo-controlled crossover trial to investigate the effect of atorvastatin on HIV-1 RNA (primary objective) and cellular markers of immune activation (secondary objective). HIV-infected individuals not receiving antiretroviral therapy were randomized to receive either 8 weeks of atorvastatin (80 mg) or placebo daily. After a 4-6 week washout phase, participants switched treatment assignments. The study had 80% power to detect a 0.3 log(10) decrease in HIV-1 RNA level. Expression of CD38 and HLA-DR on CD4(+) and CD8(+) T cells was used to measure immune activation. RESULTS: Of 24 randomized participants, 22 completed the study. Although HIV-1 RNA level was unaffected by the intervention (-0.13 log(10) copies/mL; P = .85), atorvastatin use resulted in reductions in circulating proportions of CD4(+) HLA-DR(+) (-2.5%; P = .02), CD8(+) HLA-DR(+) (-5%; P = .006), and CD8(+) HLA-DR(+) CD38(+) T cells (-3%; P = .03). Reductions in immune activation did not correlate with declines in serum levels of low-density lipoprotein cholesterol. CONCLUSIONS: Short-term use of atorvastatin was associated with modest but statistically significant reductions in the proportion of activated T lymphocytes.

Health care workers and researchers traveling to developing-world clinical settings: disease transmission risk and mitigation.

With the recent emphasis on funding and training opportunities for global health and humanitarian aid and the increased interest in the field, many health care workers and medical researchers are traveling from resource-replete to resource-limited settings. This type of travel brings unique disease risks not routinely considered for the business or vacationing traveler. This review provides practical advice for this special population of travelers, targeted to specific health care-related risks (needlestick, hemorrhagic fever viruses, severe viral respiratory disease, and tuberculosis), with suggestions for risk mitigation.

An outbreak of Plasmodium falciparum malaria in U.S. Marines deployed to Liberia.

In 2003, 44 U.S. Marines were evacuated from Liberia with either confirmed or presumed Plasmodium falciparum malaria. An outbreak investigation showed that only 19 (45%) used insect repellent, 5 (12%) used permethrin-treated clothing, and none used bed netting. Adherence with weekly mefloquine (MQ) was reported by 23 (55%). However, only 4 (10%) had serum MQ levels high enough to correlate with protection (> 794 ng/mL), and 9 (22%) had evidence of steady-state kinetics (MQ carboxy metabolite/MQ > 3.79). Tablets collected from Marines met USP identity and dissolution specifications for MQ. Testing failed to identify P. falciparum isolates with MQ resistance. This outbreak resulted from under use of personal protective measures and inadequate adherence with chemophrophylaxis. It is essential that all international travelers make malaria prevention measures a priority, especially when embarking to regions of the world with high transmission intensity such as west Africa..

Serum lipid profiles among patients initiating ritonavir-boosted atazanavir versus efavirenz-based regimens.

BACKGROUND: Antiretrovirals used to treat HIV-infected patients have the potential to adversely affect serum lipid profiles and increase the risk of cardiovascular disease which is an emerging concern among HIV-infected patients. Since boosted atazanavir and efavirenz are both considered preferred antiretrovirals a head to head comparison of their effects on serum lipids is needed. AIM: The primary objective of the study was to compare the effects of atazanavir (boosted and unboosted) and efavirenz based regimens on serum lipid profiles. STUDY DESIGN: Prospective cohort study nested within three ongoing cohorts of HIV-infected individuals. STUDY POPULATION AND METHODS: Participants initiating either atazanavir or efavirenz based regimens with documented pre- and post-initiation lipid values. Multivariate linear regression was conducted to estimate adjusted mean differences between treatment groups for high density lipoprotein cholesterol (HDL-c), non-HDL-c, and log total cholesterol (TC) to HDL-c ratio outcomes; log-linear regression models were used to estimate differences in prevalence of low HDL-c and desirable TC. RESULTS: The final study population was comprised of 380 efavirenz and 281 atazanavir initiators. Both atazanavir and efavirenz users had increases in serum HDL-c and decreases in TC/HDL ratio. In comparison to individuals initiating efavirenz, boosted atazanavir users on average had lower HDL-c (-4.12 mg/dl, p < 0.001) and non HDL-c (-5.75 mg/dl, p < 0.01), but similar declines in TC/HDL ratio. CONCLUSION: Both efavirenz and atazanavir-based regimens (boosted and unboosted) resulted in similar beneficial declines in the TC/HDL ratio.

Guidelines for the prevention of infection after combat-related injuries.

Management of combat-related trauma is derived from skills and data collected in past conflicts and civilian trauma, and from information and experience obtained during ongoing conflicts. The best methods to prevent infections associated with injuries observed in military combat are not fully established. Current methods to prevent infections in these types of injuries are derived primarily from controlled trials of elective surgery and civilian trauma as well as retrospective studies of civilian and military trauma interventions. The following guidelines integrate available evidence and expert opinion, from within and outside of the US military medical community, to provide guidance to US military health care providers (deployed and in permanent medical treatment facilities) in the diagnosis, treatment, and prevention of infections in those individuals wounded in combat. These guidelines may be applicable to noncombat traumatic injuries under certain circumstances. Early wound cleansing and surgical debridement, antibiotics, bony stabilization, and maintenance of infection control measures are the essential components to diminish or prevent these infections. Future research should be directed at ideal treatment strategies for prevention of combat-related injury infections, including investigation of unique infection control techniques, more rapid diagnostic strategies for infection, and better defining the role of antimicrobial agents, including the appropriate spectrum of activity and duration.

Trauma-related infections in battlefield casualties from Iraq.

OBJECTIVE: To describe risks for, and microbiology and antimicrobial resistance patterns of, war trauma associated infections from Operation Iraqi Freedom. BACKGROUND: : The invasion of Iraq resulted in casualties from high-velocity gunshot, shrapnel, and blunt trauma injuries as well as burns. Infectious complications of these unique war trauma injuries have not been described since the 1970s. METHODS: Retrospective record review of all trauma casualties 5 to 65 years of age evacuated from the Iraqi theatre to U.S. Navy hospital ship, USNS Comfort, March to May 2003.War trauma-associated infection was defined by positive culture from a wound or sterile body fluid (ie, blood, cerebrospinal fluid) and at least two of the following infection-associated signs/symptoms: fever, dehiscence, foul smell, peri-wound erythema, hypotension, and leukocytosis. A comparison of mechanisms of injury, demographics, and clinical variables was done using multivariate analysis. RESULTS: Of 211 patients, 56 met criteria for infection. Infections were more common in blast injuries, soft tissue injuries, >3 wound sites, loss of limb, abdominal trauma, and higher Injury Severity Score (ISS). Wound infections accounted for 84% of cases, followed by bloodstream infections (38%). Infected were more likely to have had fever prior to arrival, and had higher probability of ICU admission and more surgical procedures. Acinetobacter species (36%) were the predominant organisms followed by Escherichia coli and Pseudomonas species (14% each). CONCLUSIONS: Similar to the Vietnam War experience, gram-negative rods, particularly Acinetobacter species, accounted for the majority of wound infections cared for on USNS Comfort during Operation Iraqi Freedom. Multidrug resistance was common, with the exception of the carbapenem class, limiting antibiotic therapy options.

Multidrug-resistant tuberculosis in military recruits.

We conducted a tuberculosis contact investigation for a female military recruit with an unreported history of multidrug-resistant tuberculosis (MDRTB) and subsequent recurrence. Pertinent issues included identification of likely contacts from separate training phases, uncertainty on latent MDRTB infection treatment regimens and side effects, and subsequent dispersal of the contacts after exposure.

Vaccination in patients with HIV infection.

Although vaccine-preventable diseases are common in HIV, concerns about vaccine safety and lack of efficacy in this patient population often lead to missed opportunities for vaccination. In this article, we review the literature regarding vaccine risks and benefits and offer recommendations regarding their use and timing in patients with HIV infection.

Comparisons of causes of death and mortality rates among HIV-infected persons: analysis of the pre-, early, and late HAART (highly active antiretroviral therapy) eras.

METHODS: Comparisons of death-related variables during the 3 eras were performed. RESULTS: The number of deaths declined over the study period, with 987 deaths in the pre-HAART era, 159 deaths in the early HAART era (1997-1999), and 78 deaths in the late HAART era (2000-2003) (P < 0.01). The annual death rate peaked in 1995 (10.3 per 100 patients) and then declined to <2 deaths per 100 persons in the late HAART era (P < 0.01). The proportion of deaths attributable to infection decreased, but infection remained the leading cause of death in our cohort, followed by cancer. Of those who died, there was an increasing proportion of non-HIV-related deaths (32% vs. 9%; P < 0.01), including cardiac disease (22% vs. 8%; P < 0.01) and trauma (8% vs. 2%; P = 0.01) in the post-HAART versus pre-HAART era. Despite the absence of intravenous drug use and the low prevalence of hepatitis C coinfection in our cohort, an increasing proportion of deaths in the HAART era were attributable to liver disease, although the numbers are small. CONCLUSIONS: Despite increasing concerns regarding antiretroviral resistance, the death rate among HIV-infected persons in our cohort continues to decline. Our data show a lower death rate than that reported among many other US HIV-infected populations; this may be the result of open access to health care. A shift in the causes of death toward non-HIV-related causes suggests that a more comprehensive health care approach may be needed for optimal life expectancy; this may include enhanced screening for malignancy and heart disease as well as preventive measures for liver disease and accidents.

Use of bilirubin as a marker of adherence to atazanavir-based antiretroviral therapy.

We retrospectively reviewed 134 patients to evaluate atazanavir-related bilirubin elevation as an adherence marker. Using a 2 log reduction or undetectable viral load as a marker for suppression, the median bilirubin increase at first follow-up was 1.3 (0.7-2.2), versus 0.2 (-0.05-0.65) for those not suppressed. An increase in bilirubin of more than 0.4 mg/dl correctly classified 81% of patients as having successful treatment response (sensitivity 87%, specificity 63%), suggesting that bilirubin is a good adherence marker.

Safety and immunogenicity of an inactivated hepatitis A vaccine among HIV-infected subjects.

BACKGROUND: Hepatitis A is a major health risk for many human immunodeficiency virus (HIV)-infected individuals. Vaccination is a potentially attractive measure to reduce the incidence of hepatitis A among this population, but data on its safety and immunogenicity are incomplete. METHODS: Ninety HIV-uninfected adults received an inactivated hepatitis A vaccine (VAQTA; Merck), and 90 HIV-infected subjects were randomized, in double-blind fashion, to receive either the vaccine or placebo. The HIV-infected subjects were stratified by CD4 cell count, with 45 subjects having CD4 cell counts of > or =300 cells/mm3 and 45 subjects having CD4 cell counts of <300 cells/mm3. Vaccine was given at weeks 0 and 24 of the study.Results. Seroconversion rates at week 28 of the study were 94% among the HIV-infected subjects and 100% among the HIV-uninfected control subjects. HIV-infected subjects with CD4 cell counts of <300 cells/mm3 had a seroconversion rate of 87%, and HIV-infected subjects with CD4 cell counts of > or =300 cells/mm3 had a seroconversion rate of 100%. The vaccine was generally well tolerated, and no adverse effect on either HIV load or CD4 cell count was found. CONCLUSION: Hepatitis A vaccine was both immunogenic and safe among HIV-infected subjects.

Unintended smallpox vaccination of HIV-1-infected individuals in the United States military.

We identified 10 individuals who had undiagnosed human immunodeficiency virus type 1 (HIV-1) infection at the time of smallpox vaccination. Mean CD4 cell count was 483 cells/mm3 (range, 286-751 cells/mm3), and mean log10 plasma HIV-1 RNA load was 4.13 copies/cm3 (range, 2.54-5.16 copies/cm3). All vaccinees (3 primary and 7 repeat) had a normal, robust reaction without complications. Smallpox vaccine was well-tolerated in this small series of HIV-1-infected military personnel.

Long-term efficacy of routine access to antiretroviral-resistance testing in HIV type 1-infected patients: results of the clinical efficacy of resistance testing trial.

The long-term efficacy of making resistance testing routinely available to clinicians has not been established. We conducted a clinical trial at 6 US military hospitals in which volunteers infected with human immunodeficiency virus type-1 were randomized to have routine access to phenotype resistance testing (PT arm), access to genotype resistance testing (GT arm), or no access to either test (VB arm). The primary outcome measure was time to persistent treatment failure despite change(s) in antiretroviral therapy (ART) regimen. Overall, routine access to resistance testing did not significantly increase the time to end point. Time to end point was significantly prolonged in the PT arm for subjects with a history of treatment with > or =4 different ART regimens or a history of treatment with nonnucleoside reverse-transcriptase inhibitors before the study, compared with that in the VB arm. These results suggest that routine access to resistance testing can improve long-term virologic outcomes in HIV-infected patients who are treatment experienced but may not impact outcome in patients who are naive to or have had limited experience with ART.