A severe influenza vaccine shortage occurred during the 2004-2005 influenza season because of the loss of all vaccine made by Chiron (Emeryville, CA) for US distribution.
The objectives of this study were to assess among pediatricians nationally: (1) influenza vaccine-delivery strategies; (2) reported vaccine shortages and factors associated with experiencing shortages; and (3) the impact of shortages on vaccine redistribution, patient referral, and clinical practice, including patient prioritization.
A survey was administered in March 2005 through June 2005 to 427 pediatricians who participated in a national network representative of the American Academy of Pediatrics membership. RESULTS. Our response rate was 82%. Thirty-nine percent of the pediatricians had a computerized method for identifying patients at high risk needing vaccination. Ninety-four percent and 79% reported giving high-priority to children >/=24 months old with high-risk conditions and children 6 to 23 months old, respectively, whereas 41% gave high-priority to household contacts and caregivers of children <6 months old. Forty-three percent reported experiencing shortages of vaccine for patients at high risk, whereas only 14% ordered Chiron vaccine. In multivariate analyses, ordering vaccine from Chiron and ordering Aventis Pasteur (Lyon, France) vaccine solely from a vaccine distributor were associated with experiencing a shortage. Forty-eight percent of respondents obtained additional vaccine from another source, most frequently the public health sector, whereas 37% reported selling or giving away vaccine. In addition, 47% referred patients at high risk elsewhere for vaccination, primarily to public health clinics. Forty-nine percent reported having unused vaccine remaining at the end of the season.
Although few pediatricians ordered Chiron vaccine, substantial influenza vaccine shortages were reported, highlighting the tenuousness of injectable influenza vaccine supplies for children. The extensive redistribution of vaccine suggests that cooperative efforts between the private and public sectors were widespread. Efforts to vaccinate patients at high risk during shortages would be aided by better systems to identify and recall these patients.
"However, during several recent seasons, vaccine supplies have been compromised raising concern whether sufficient vaccine will consistently meet the demand.     Intradermal vaccination may facilitate the goal of universal vaccination by sparing the amount of antigen needed and offering an alternative to intramuscular injection. Becton Dickinson has developed a novel system, BD Soluvia™, to test this hypothesis. "
[Show abstract][Hide abstract] ABSTRACT: The aim of the study was to determine whether reduced doses of trivalent inactivated influenza vaccine (TIV) administered by the intradermal (ID) route generated similar immune responses to standard TIV given intramuscularly (IM) with comparable safety profiles. Recent changes in immunization recommendations have increased the number of people for whom influenza vaccination is recommended. Thus, given this increased need and intermittent vaccine shortages, means to rapidly expand the vaccine supply are needed. Previously healthy subjects 18-64 years of age were randomly assigned to one of four TIV vaccine groups: standard 15 μg HA/strain TIV IM, either 9 μg or 6 μg HA/strain of TIV ID given using a new microinjection system (BD Soluvia™ Microinjection System), or 3 μg HA/strain of TIV ID given by Mantoux technique. All vaccines contained A/New Caledonia (H1N1), A/Wyoming (H3N2) and B/Jiangsu strains of influenza. Sera were obtained 21 days after vaccination and hemagglutination inhibition (HAI) assays were performed and geometric mean titers (GMT) were compared among the groups. Participants were queried immediately following vaccination regarding injection pain and quality of the experience. Local and systemic reactions were collected for 7 days following vaccination and compared. Ten study sites enrolled 1592 subjects stratified by age; 18-49 years [N=814] and 50-64 years [N=778]. Among all subjects, for each of the three vaccine strains, the GMTs at 21 days post-vaccination for both the 9 μg and the 6 μg doses of each strain given ID were non inferior to GMTs generated after standard 15 μg doses/strain IM. However, for the 3 μg ID dose, only the A/Wyoming antigen produced a GMT that was non-inferior to the standard IM dose. Additionally, in the subgroup of subjects 50-64 years of age, the 6μg dose given ID induced GMTs that were inferior to the standard IM TIV for the A/H1N1 and B strains. No ID dose produced a GMT superior to that seen after standard IM TIV. Local erythema and swelling were significantly more common in the ID groups but the reactions were mild to moderate and short-lived. No significant safety issues related to intradermal administration were identified. Participants given TIV ID provided favorable responses to questions about their experiences with ID administration. In conclusion, for the aggregated cohorts of adults 18-64 years of age, reduced doses (6 μg and 9 μg) of TIV delivered ID using a novel microinjection system stimulated comparable HAI antibody responses to standard TIV given IM. The reduced 3 μg dose administered ID by needle and syringe, as well as the 6 μg ID for subjects aged 50-64 years of age generated poorer immune responses as compared to the 15 μg IM dose.
[Show abstract][Hide abstract] ABSTRACT: Adaptive array weight adjustment algorithms are described by time varying stochastic differential equations. A new method employing a two-variable perturbation analysis is used to investigate the effects of the weight fluctuations on the Applebaum algorithm performance in the presence of multiple jammers. An explicit solution of the directivity pattern in the direction of the jammers for the two-jammer problem is derived. An improved formula for the output signal-to-interference plus noise ratio (SINR) is obtained. It is shown as expected that the greater the number of signals at the array input the greater the degradation in the directivity pattern in the direction of the interfering signals and the greater the degradation in the output SINR. In addition, we show that the performance degrades uncontrollably when the number of independent jammers approaches the number of array elements. A comparison is made of the new results and those obtained using standard approximations. Substantial differences are caused by first-order terms in the perturbation.
Military Communications Conference, 1985. MILCOM 1985. IEEE; 11/1985
[Show abstract][Hide abstract] ABSTRACT: The combination of coding and low index modulation can result in both bandwidth and power efficient modem design. The low index modulation format is obtained by using a frequency division and multiplication network to alter the modulation index of Â½ for convertioned MSK to a lower value. This lower value modulation index in concert with restricted range encoding provides a system that can achieve a 2 bits/sec/Hz bandwidth efficiency at a power level equivalent to that required for MSK. The design concepts are such that data rates in the hundreds of megabits/second are practical.
Military Communications Conference, 1985. MILCOM 1985. IEEE; 11/1985
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