2 research outputs found
Efficacy and Safety of CVT-E002, a Proprietary Extract of <i>Panax quinquefolius</i> in the Prevention of Respiratory Infections in Influenza-Vaccinated Community-Dwelling Adults: A Multicenter, Randomized, Double-Blind, and Placebo-Controlled Trial
Get PDFCVT-E002 (a proprietary extract) was found to be effective in the prevention of upper respiratory infections (URIs) in healthy adults, and institutionalized and community-dwelling seniors. A multicenter, randomized, double-blind, placebo-controlled trial was carried out to determine effects of CVT-E002 in the prevention of URIs in influenza-vaccinated community-dwelling adults. 783 community-dwelling adults were randomized to receive placebo, 400 mg or 800 mg treatment/d (1 : 1 : 1) for 6 months. Primary analysis on the incidence of laboratory-confirmed-clinical URIs (LCCUs), including influenza A and B, was performed on those receiving at least one dose. Secondary analysis was performed on study completers and included incidence, severity, and duration of URIs meeting a Jackson-based criteria and safety of CVT-E002. The incidence of LCCUs in the ITT group was 5.5%, 5.2%, and 4.6% in the placebo, 400 mg and 800 mg groups, respectively (P=0.89). Jackson-confirmed URIs were significantly lower in the treated groups (P<0.04). CVT-E002 supplementation reduced the severity and duration of Jackson-confirmed URIs. The results indicate that CVT-E002 can be safely used by similar groups and may prevent symptoms of URIs; larger sample size is warranted.</jats:p
Estimating the impact of influenza vaccination and antigenic drift on influenza-related morbidity and mortality in England & Wales using hidden Markov models
Get PDFInfluenza causes substantial morbidity and mortality in some influenza sea-
sons, especially among the elderly. Influenza seasons dominated by circula-
tion of influenza A/H3N2 virus tend to result in more morbidity and mor-
tality than seasons dominated by influenza A/H1N1 or influenza B viruses.
Influenza viruses undergo constant mutation, called antigenic drift, which
is largely driven by host immunity. It has been shown that antigenic drift
in influenza A/H3N2 virus proceeds in a punctuated, as opposed to contin-
uous, fashion. A cluster of antigenically similar influenza A/H3N2 viruses
appears to remain dominant for between 1 and 8 influenza seasons before
being supplanted by a new cluster. Influenza seasons when a new cluster
becomes dominant may result in higher morbidity and mortality than other
seasons. Influenza vaccine effectiveness varies between influenza seasons be-
cause of the different subtypes in circulation and the degree of antigenic
match between vaccine and circulating variants. In each influenza season in
recent years, over 70% of the population of England & Wales aged > 65 has
been vaccinated, though the impact of this high coverage on population level
morbidity and mortality is unknown. Multivariate time series models were
fitted to reports of laboratory confirmed influenza, sentinel general practi-
tioner (GP) consultations for influenza-like-illness, and all deaths registered
to underlying pneumonia or influenza in England & Wales from 1975/76 to
2004/05. The models successfully distinguish influenza
- attributable GP
consultations and deaths from GP consultations and deaths that would be
expected in the absence of influenza. This distinction is made jointly by
the laboratory reports and the non-laboratory confirmed surveillance data.
It is not possible to use the multivariate time series models to quantify
the average effect of the appearance of a new cluster of influenza A/H3N2
virus variants, or vaccine impact, on influenza
- attributable morbidity or
mortality in the data analyzed. Reasons for this are discu
