Stabilization of HAC1 Influenza Vaccine by Spray Drying: Formulation Development and Process Scale-Up

Purpose

Stable vaccines with long shelf lives and reduced dependency on the cold chain are ideal for stockpiling and rapid deployment during public emergencies, including pandemics. Spray drying is a low-cost process that has potential to produce vaccines stable at a wide range of temperatures. Our aim was to develop a stable formulation of a recombinant H1N1 influenza hemagglutinin vaccine candidate and take it to pilot-scale spray-drying production.

Methods

Eight formulations containing different excipients were produced and assayed for antigen stability, powder characteristics, and immunogenicity after storage at a range of temperatures, resulting in the identification of four promising candidates. A pilot-scale spray-drying process was then developed for further testing of one formulation.

Results

The pilot-scale process was used to reproducibly manufacture three batches of the selected formulation with yields >90%. All batches had stable physical properties and in vitro potency for 6 months at temperatures from ?20°C to +50°C. Formulations stored for 3 months elicited immunogenic responses in mice equivalent to a frozen lot of bulk vaccine used as a stability control.

Conclusions

This study demonstrates the feasibility of stabilizing subunit vaccines using a spray-drying process and the suitability of the process for manufacturing a candidate product.

     

Understanding the Burden of Tuberculosis Among American Indians/Alaska Natives in the U.S.: A Validation Study

Objective

We validated cases of active tuberculosis (TB) recorded in the Indian Health Service (IHS) National Patient Information Reporting System (NPIRS) and evaluated the completeness of TB case reporting from IHS facilities to state health departments.

Methods

We reviewed the medical records of American Indian/Alaska Native (AI/AN) patients at IHS health facilities who were classified as having active TB using International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM) diagnostic codes from 2006 to 2009 for clinical and laboratory evidence of TB disease. Individuals were reclassified as having active TB disease; recent latent TB infection (LTBI); past positive tuberculin skin test (TST) only; or as having no evidence of TB, LTBI, or a past positive TST. We compared validated active TB cases with corresponding state records to determine if they were reported.

Results

The study included 596 patients with active TB as per ICD-9-CM codes. Based on chart review, 111 (18.6%) had active TB; 156 (26.2%) had LTBI; 104 (17.4%) had a past positive TST; and 221 (37.1%) had no evidence of TB disease, LTBI, or a past positive TST. Of the 111 confirmed cases of active TB, 89 (80.2%) resided in participating states; 81 of 89 (91.2%) were verified as reported TB cases.

Conclusions

ICD-9-CM codes for active TB disease in the IHS NPIRS do not accurately reflect the burden of TB among AI/ANs. Most confirmed active TB cases in the IHS health system were reported to the state; the national TB surveillance system may accurately represent the burden of TB in the AI/AN population.Tuberculosis (TB) is a bacterial infection caused by Mycobacterium tuberculosis (M. tuberculosis) complex. Treatment for active TB disease requires months of combination drug therapy. Left untreated, TB can result in substantial morbidity and occasionally death. Although the number of TB cases in the United States has steadily declined during the past two decades, TB remains a major health concern within many subgroups, including American Indians/Alaska Natives (AI/ANs). The TB case rate among AI/ANs is estimated at 5.6 per 100,000 population, notably higher than the national average of 3.4 cases per 100,000 population.¹Surveillance of active TB disease is an important component of monitoring and controlling the spread of TB. Currently, annual rates of TB in the U.S. are calculated by the Centers for Disease Control and Prevention (CDC) National Tuberculosis Surveillance System (NTSS).¹ The NTSS is an electronic database that relies on the collaboration of state and local health departments; each person diagnosed with TB disease is verified as an incident case of TB and reported using a standard TB case form. The criteria for TB disease surveillance are based on a laboratory case definition, clinical case definition, or provider diagnosis.^1,2 The laboratory case definition requires isolation of M. tuberculosis complex in culture or detection of M. tuberculosis complex nucleic acids by amplification testing or demonstration of acid-fast bacilli in a clinical specimen when a culture cannot be obtained. The clinical case definition requires (1) a positive tuberculin skin test (TST), (2) signs and symptoms compatible with TB, (3) treatment with at least two anti-TB medications, and (4) a completed diagnostic evaluation. A provider diagnosis is used when the clinical presentation is consistent with TB but the criteria to meet laboratory or clinical case definitions are not met.The Indian Health Service (IHS), an agency of the U.S. Department of Health and Human Services, provides comprehensive health-care services through IHS, Tribal, and Urban Indian facilities (collectively referred to hereafter as IHS) to eligible AI/AN people who are members of 566 federally recognized Tribes. IHS provides care for approximately 2.1 million (62%) of the nation''s estimated 3.4 million AI/ANs.³ The IHS maintains a national database, the National Patient Information Reporting System (NPIRS).⁴ Within NPIRS, diseases and conditions are coded according to the International Classification of Diseases, Ninth Revision, Clinical Modification (ICD-9-CM).⁵ In addition, IHS is in the process of implementing an electronic health record (EHR) system.⁶ Electronic data collected by IHS have the potential to serve as a resource to better understand the burden and monitor trends of TB disease within the AI/AN population; yet, the accuracy of NPIRS for identifying people with TB disease has not been previously established. Several previous studies in other U.S. populations have cited wide variability (0%–77%) in the positive predictive value (PPV) of ICD-9-CM diagnostic codes for active TB disease.^7–13CDC provides guidance for IHS providers to report all nationally notifiable diseases, including TB, to local and state authorites.^1,2 However, there are no explicit mechanisms for IHS to report cases of TB directly to the NTSS, and the extent to which IHS facilities collaborate with local authorities on case reporting is not well understood.We validated active cases of TB disease within the AI/AN population by reviewing the medical charts of individuals assigned an active TB disease ICD-9-CM code in the inpatient and outpatient NPIRS visit data from 2006 to 2009 to determine the completeness of reporting TB disease by examining whether validated TB cases from IHS facilities were reported to state health departments.     

Vending Machines in Australian Hospitals: Are They Meeting the Needs of the Consumer?

The current report explores how well vending machines are meeting the needs of health care organizations and their staff and visitors in Australia. Hospital vending machines often provide the only source of food through the night to staff and visitors and traditionally offer less-healthy options. Findings presented in this report suggest that vending machines are not meeting current statewide policies and guidelines for healthier food environments in health care. This is despite widespread support for healthier refreshments in hospitals by staff, visitors, and patients. Alternatives to traditional vending and opportunities for nutrition educators and researchers are discussed.     

Hypoxia and hypercapnia in infants with mild laryngomalacia

We evaluated 15 infants with laryngomalacia and 12 healthy infants to determine their risk of hypoxia and hypercapnia as complications of partial upper airway obstruction. Transcutaneous carbon dioxide pressure and oxygen pressure were recorded continuously overnight with episodes of hypercapnia and/or hypoxia scored for frequency, duration, and relationship to activity. Episodes occurred in 12 infants with laryngomalacia and eight control infants. Infants with laryngomalacia had significantly more episodes. The greatest decrease in transcutaneous oxygen pressure was 29 mm Hg and increase in transcutaneous carbon dioxide pressure was 31 mm Hg, both occurring in infants with laryngomalacia. Three infants had prolonged episodes of hypoxia and hypercapnia. History or physical examination did not distinguish those infants with laryngomalacia who had hypercapnia and/or hypoxia from those without episodes. Two- to 15-month follow-ups in 13 infants with laryngomalacia revealed that symptoms were unchanged or improved. Twelve of these 13 infants had normal growth without developmental delay or other complications. These results demonstrate that episodes of hypoxia and hypercapnia occur more frequently in infants with laryngomalacia than in control infants; however, their apparent risk for complications is low.     

Antimicrobial peptides in animals and their role in host defences

Domesticated animals have a large variety of antimicrobial peptides that serve as natural innate barriers limiting microbial infection or, in some instances, act as an integral component in response to inflammation or microbial infection. These peptides differ in size, composition, mechanisms of activity and range of antimicrobial specificities. They are expressed in many tissues, polymorphonuclear leukocytes, macrophages and mucosal epithelial cells. There is a small group of anionic antimicrobial peptides found in ruminants and a much larger group of cationic antimicrobial peptides found in all domesticated animals. The cationic peptides include linear, helical peptides, linear peptides rich in proline and cysteine-stabilized peptides with a beta-sheet and are commonly referred to as cathelicidins and defensins. These peptides are generally broad-spectrum for Gram-positive bacteria, Gram-negative bacteria and fungi (e.g. myeloid antimicrobial peptides, alpha-, beta-defensins, and protegrins) or are specific to one of these groups (e.g. porcine cecropin P1, Bac5, Bac7, PR-39 and prophenin).     

Mechanisms responsible for longitudinal growth of the cortex: coalescence of trabecular bone into cortical bone

BACKGROUND: The purpose of the present study was to determine whether longitudinal growth of the cortex occurs through intramembranous bone formation involving the periosteum or through endochondral bone formation involving the growth plate and to explore the cellular and biochemical mechanisms responsible for this process. METHODS: Cortical bone formation was studied in the metaphyses of growing New Zealand White rabbits by means of (1) oxytetracycline labeling and fluorescence microscopy, (2) computer-assisted histomorphometry, (3) osteoblast culture and [(3) H]-thymidine incorporation in the presence of periosteum or periosteum-conditioned medium, and (4) surgical insertion of membranes between the periosteum and the underlying spongiosa. RESULTS: Within the metaphyseal cortex, oxytetracycline labeling produced fluorescent closed curves outlining enlarging trabeculae derived from coalescing endochondral trabecular bone. In this region of coalescing trabeculae close to the periosteum, osteoblast surface was increased compared with trabeculae farther from the periosteum (p < 0.001). The osteoclast surface did not differ. In vitro, osteoblast proliferation was increased in the presence of periosteum (p < 0.001) or periosteum-conditioned medium (p < 0.001). Surgical insertion of permeable or impermeable membranes between the periosteum and the spongiosa did not prevent cortex formation. CONCLUSIONS: These observations demonstrate that metaphyseal cortical bone is formed by coalescence of endochondral trabecular bone. This coalescence is associated with increased osteoblast surface in the peripheral spongiosa. The increased osteoblast surface could be due to inductive effects of periosteum; in the present study, periosteum stimulated osteoblast proliferation in vitro but was not required for metaphyseal cortical bone formation in vivo. Clinical Relevance: Understanding metaphyseal cortical growth may help to elucidate the pathophysiology of osseous growth disorders in children.     

Occupational risk of the acquired immunodeficiency syndrome among health care workers

In August 1983, we initiated nationwide prospective surveillance of health care workers with documented parenteral or mucous-membrane exposures to blood or other body fluids of patients with the acquired immunodeficiency syndrome (AIDS) or AIDS-related illnesses. The purpose of the surveillance project is to quantitate prospectively the risk to health care workers of acquiring the AIDS virus, human T-cell lymphotropic virus Type III/lymphadenopathy-associated virus (HTLV-III/LAV), as a result of occupational exposures. By December 31, 1985, 938 health care workers were being followed in the surveillance project. The mean length of follow-up was 15 months (range, 0 to 56) and 531 health care workers (57 percent) had been followed for more than one year. Needlestick injuries and cuts with sharp instruments accounted for 76 percent of the exposures. Over 85 percent of all exposures were to blood or serum. None of the health care workers have acquired signs or symptoms of AIDS. Analyses of T-lymphocyte subsets were performed for 341 (36 percent) of the exposed health care workers, and tests for antibody to HTLV-III/LAV were performed for 451 (48 percent). Seven health care workers who had low helper/suppressor T-lymphocyte ratios on initial testing were retested; only three had persistently low ratios. Only two health care workers tested were seropositive for antibody to HTLV-III/LAV. The results of this surveillance project, thus far, suggest that the risk to health care workers of occupational transmission of HTLV-III/LAV is low (the upper bound of the 95 percent confidence interval for the seroprevalence rate among workers with greater than or equal to 3 months of follow-up with HTLV-III/LAV antibody testing is 1.65 percent) and appears to be related to parenteral exposure to blood.