flu
Influenza (H1N1)-ISCOMs enhance immune responses and protection in aged mice.

Sambhara S, Woods S, Arpino R, Kurichh A, Tamane A, Bengtsson KL, Morein B, Underdown B, Klein M, Burt D.

Pasteur Merieux Connaught Canada, North York, Ontario, Canada.

Aging is associated with a decline in immune function and the elderly are therefore more susceptible to infectious disease and less responsive to vaccination. Influenza antigens complexed as immunostimulatory complexes (ISCOMs) generate more potent protective immune responses compared with non-adjuvanted flu antigens in young adult mice. We report on the protective efficacy of flu-ISCOMs compared with the current split flu vaccine in an aged mouse model. DBA/2 mice aged 2 or 18 months were immunized with flu vaccine, ISCOMs or live virus, prior to challenge with the homologous virus. In aged mice, flu-ISCOMs induced significantly higher serum hemagglutination inhibition (HAI) titers compared to vaccine, similar to the levels obtained in young adult mice that received the split vaccine. Flu-ISCOMs but not vaccine induced cytotoxic T lymphocyte (CTL) responses in young and to a lesser degree in aged mice. In aged mice flu-ISCOMs significantly reduced illness and enhanced recovery from viral infection compared with vaccine. Our data suggests that flu-ISCOMs may offer an improved vaccine strategy for protection of elderly humans against the complications of influenza infection.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=9223118&dopt=Abstract flu, flu medicine, tamiflu



flu
Pandemic influenza: confronting a re-emergent threat. The 1976 experience.

Dowdle WR.

The Task Force for Child Survival and Development, Atlanta, Georgia 30307, USA.

The Swine Influenza Immunization Program began in January 1976 with an outbreak of swine influenza among trainees at Ft. Dix, New Jersey. The program ended in December 1976 after an increased incidence of Guillain-Barre syndrome was attributed to the vaccine. The issues and events of 1976 provide valuable lessons for the future. A thorough and objective review of the swine flu program should be a prerequisite for influenza pandemic planning. Strong consideration should be given to creating separate structures for risk assessment and risk management. Risk assessment estimates the probability of a pandemic, the options available for control, and the relative benefits of those options as situations change. Risk management is the political response to that assessment.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=9240699&dopt=Abstract flu, flu medicine, tamiflu



flu
Assessing influenza immunization rates in Medicare managed care plans: a comparison of three methods.

Ballard JE, Liu J, Uberuagua D, Mustin HD, Sugarman JR.

PRO-West, Seattle, WA 98133-9075, USA. wapro.jballard sdps.org

BACKGROUND: In an effort to improve care delivered to Medicare beneficiaries, the Health Care Financing Administration (HCFA) has encouraged competitive Medicare risk plans to collaborate on quality improvement projects. PRO-West, a private, nonprofit quality improvement organization, fostered a collaboration of all Medicare risk plans in Washington State in order to assess and improve influenza immunization rates among seniors enrolled in managed care. METHODOLOGY: After the 1994-1995 influenza immunization season, immunization rates were determined for each participating plan from administrative data and medical record review. In the 1995-1996 season, these methods were supplemented with a telephone survey. The survey was used to identify perceived barriers to immunization and to estimate immunization rates. RESULTS: Immunization rates, as estimated by administrative data and medical record review, were similar for both years. The average immunization rate using administrative data for the 1995-1996 flu season was 60.6% (range, 42.8% to 72.3%). The estimated rate increased to 77.8% (95% confidence interval, 75.3% to 80.3%) when the telephone survey data were added. Medical record review contributed little additional information. CONCLUSIONS: Influenza immunization rates for seniors enrolled in Medicare risk plans in Washington State exceed those reported for fee-for-service Medicare beneficiaries. Telephone surveys resulted in higher and probably more valid estimates of influenza immunization rates than did analysis of administrative data and medical records. Plans with lower rates can emulate "benchmark" plans that are explicit about the methods they use to achieve high coverage rates. Medicare risk health plans competing in the same markets can collaborate in quality assessment activities in an effective manner.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=9330084&dopt=Abstract flu, flu medicine, tamiflu



flu
Syncytium formation and HIV-1 replication are both accentuated by purified influenza and virus-associated neuraminidase.

Sun J, Barbeau B, Sato S, Boivin G, Goyette N, Tremblay MJ.

Centre de Recherche en Infectiologie, Hopital du Centre Hospitalier Universitaire de L'Universite Laval, Quebec G1V 4G2, Canada.

The degree of sialylation has been shown previously to modulate the process of human immunodeficiency virus type-1 (HIV-1) infection by affecting the interaction between the virus and CD4-expressing target cells. In the present study, we investigated whether HIV-1 replication cycle was affected by neuraminidase (NA) derived from the human influenza (flu) virus. We first demonstrate that the level of HIV-1-mediated syncytium formation was greatly enhanced in the presence of purified flu NA. Pretreatment of established monocytic and lymphocytic cell lines as well as primary mononuclear cells with purified flu NA augmented also the process of virus infection. A comparable up-regulating effect was observed when using several strains of UV-inactivated whole flu virus, thereby suggesting that virus-anchored NA enzymes positively modulate the HIV-1 life cycle. Furthermore, flu NA-mediated positive effect on HIV-1 biology was abrogated with zanamivir, a specific flu NA inhibitor. Our results provide a new model allowing the investigation of the potential benefit of using NA inhibitors in the treatment of HIV-1-infected patients suffering from coinfection with NA-bearing pathogens.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=11781317&dopt=Abstract flu, flu medicine, tamiflu



flu
Influenza virus vaccination of patients with multiple sclerosis.

Mokhtarian F, Shirazian D, Morgante L, Miller A, Grob D, Lichstein E.

Department of Medicine, SUNY Health Science Center/Maimonides Medical Center, Brooklyn 11219, USA.

Prior to vaccination with a trivalent influenza vaccine (AT/Texas, AB/Beijing, and BP/Panama), sera from 19 MS patients had a significantly higher mean level of antibody than 9 normal subjects to AT strain of influenza, but not to AB or BP strains. After Flu vaccination, the mean anti-AT and anti-AB antibody titers significantly increased 4-fold in 11 MS patients and 9 normal subjects. The ratio of MS responders (6/11), however, was lower than normal (8/9). The mean PBL proliferative response to the Flu antigens increased after vaccination significantly more in MS patients than in normal subjects, and increased in 9 of 11 MS patients and 3 of 9 normal subjects. Although MS patients responded to Flu antigens with higher antibody levels and proliferative responses of PBL, than normal subjects, a clinical protective effect of the vaccine against Flu was not clearly demonstrated in these patients, and vaccination did not cause or protect against exacerbation of MS.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=9372507&dopt=Abstract flu, flu medicine, tamiflu



flu
Laboratory diagnosis of acute lower respiratory tract viral infections in children.

Hijazi Z, Pacsa A, Eisa S, el Shazli A, abd el-Salam RA.

Department of Pediatric, Mubarak Al-Kabeer Hospital, Faculty of Medicine, Kuwait University, Safat, Kuwait.

This report summarizes and compares the results of complement fixation test (CFT), virus isolation (VI), and direct immunofluorescence test (DIF) for the antigen detection of respiratory syncytial virus (RSV), influenza A virus (Flu A), and adenovirus in 62 children with acute lower respiratory tract infections (ALRI) in Kuwait. It includes, as well, CFT results for parainfluenza virus and Mycoplasma pneumoniae. Combining the three methods, a potential causative agent was identified in 56 (90 per cent) children, of whom 14 (22 per cent) had evidence of infection with more than one pathogen. RSV was most frequently identified followed by Flu A, parainfluenza, Mycoplasma pneumoniae and adenovirus. Virus isolation proved the best method for identification of RSV, Flu A, and adenovirus [identified 52 (84 per cent) cases]. DIF was sensitive for RSV detection (sensitivity 84 per cent, specificity 94 per cent), and less sensitive for Flu A (sensitivity 62 per cent, specificity 98 per cent). However, DIF was completely insensitive to adenovirus (no positives). CFT was positive for the five pathogens in 44 (71 per cent) of the population studied; therefore, almost 20 per cent of positive identifications would have been missed if VI and DIF were not done. The sensitivity and specificity of CFT for RSV, adenovirus and Flu A were 71, 75, and 31 per cent, and 94, 96, and 94 per cent, respectively. Based on the results of this pilot study, it appears that a combination of the three tests yields the best rate of virus detection. Cell culture cannot be discarded for the identification of some respiratory viruses, especially adenovirus, until better techniques, or more sensitive reagents are applied. However, since RSV is the virus most commonly involved in children with ALRI, we recommend using DIF on routine basis for diagnosis. Its results compare well with virus isolation; it is simple, rapid, and inexpensive.

Online source: www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=8936958&dopt=Abstract flu, flu medicine, tamiflu