Ahmed T.,Variation Biotechnologies Inc.
The Cochrane database of systematic reviews | Year: 2013
Infection with enterotoxigenic Escherichia coli (ETEC) bacteria is a common cause of diarrhoea in adults and children in developing countries and is a major cause of 'travellers' diarrhoea' in people visiting or returning from endemic regions. A killed whole cell vaccine (Dukoral®), primarily designed and licensed to prevent cholera, has been recommended by some groups to prevent travellers' diarrhoea in people visiting endemic regions. This vaccine contains a recombinant B subunit of the cholera toxin that is antigenically similar to the heat labile toxin of ETEC. This review aims to evaluate the clinical efficacy of this vaccine and other vaccines designed specifically to protect people against diarrhoea caused by ETEC infection. To evaluate the efficacy, safety, and immunogenicity of vaccines for preventing ETEC diarrhoea. We searched the Cochrane Infectious Disease Group Specialized Register, the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, LILACS, and http://clinicaltrials.gov up to December 2012. Randomized controlled trials (RCTs) and quasi-RCTs comparing use of vaccines to prevent ETEC with use of no intervention, a control vaccine (either an inert vaccine or a vaccine normally given to prevent an unrelated infection), an alternative ETEC vaccine, or a different dose or schedule of the same ETEC vaccine in healthy adults and children living in endemic regions, intending to travel to endemic regions, or volunteering to receive an artificial challenge of ETEC bacteria. Two authors independently assessed each trial for eligibility and risk of bias. Two independent reviewers extracted data from the included studies and analyzed the data using Review Manager (RevMan) software. We reported outcomes as risk ratios (RR) with 95% confidence intervals (CI). We assessed the quality of the evidence using the GRADE approach. Twenty-four RCTs, including 53,247 participants, met the inclusion criteria. Four studies assessed the protective efficacy of oral cholera vaccines when used to prevent diarrhoea due to ETEC and seven studies assessed the protective efficacy of ETEC-specific vaccines. Of these 11 studies, seven studies presented efficacy data from field trials and four studies presented efficacy data from artificial challenge studies. An additional 13 trials contributed safety and immunological data only. Cholera vaccinesThe currently available, oral cholera killed whole cell vaccine (Dukoral®) was evaluated for protection of people against 'travellers' diarrhoea' in a single RCT in people arriving in Mexico from the USA. We did not identify any statistically significant effects on ETEC diarrhoea or all-cause diarrhoea (one trial, 502 participants, low quality evidence).Two earlier trials, one undertaken in an endemic population in Bangladesh and one undertaken in people travelling from Finland to Morocco, evaluated a precursor of this vaccine containing purified cholera toxin B subunit rather than the recombinant subunit in Dukoral®. Short term protective efficacy against ETEC diarrhoea was demonstrated, lasting for around three months (RR 0.43, 95% CI 0.26 to 0.71; two trials, 50,227 participants). This vaccine is no longer available. ETEC vaccinesAn ETEC-specific, killed whole cell vaccine, which also contains the recombinant cholera toxin B-subunit, was evaluated in people travelling from the USA to Mexico or Guatemala, and from Austria to Latin America, Africa, or Asia. We did not identify any statistically significant differences in ETEC-specific diarrhoea or all-cause diarrhoea (two trials, 799 participants), and the vaccine was associated with increased vomiting (RR 2.0, 95% CI 1.16 to 3.45; nine trials, 1528 participants). The other ETEC-specific vaccines in development have not yet demonstrated clinically important benefits. There is currently insufficient evidence from RCTs to support the use of the oral cholera vaccine Dukoral® for protecting travellers against ETEC diarrhoea. Further research is needed to develop safe and effective vaccines to provide both short and long-term protection against ETEC diarrhoea. Source
Variation Biotechnologies Inc. | Date: 2012-11-16
In one aspect, the present disclosure provides compounds of formulae (I) and (II). In another aspect, a compound of formula (I) or (II) is formulated into compositions with an antigen, optionally with a vesicle. In some embodiments, compositions are administered intramuscularly.
Variation Biotechnologies Inc. | Date: 2013-03-27
The present disclosure provides methods useful for determining levels of HCMV infection in host cells and, by extension, determining levels of neutralizing antibodies present in a sample. The present disclosure encompasses the recognition that HCMV viruses that have a fluorescent moiety permit detection of viral infection (e.g., by assessing fluorescence in cells after contacting the host cell with the virus). In some embodiments, levels of HCMV infection are determined by fluorescence detection where the virus has been preincubated with a test sample (e.g., a serum sample) from a subject. In some embodiments, the subject has been administered a candidate HCMV vaccine.
Variation Biotechnologies Inc. | Date: 2012-01-13
The present disclosure provides methods for preparing vesicles. In one aspect, the methods involve providing a molten mixture of vesicle-forming lipids and adding the molten mixture of vesicle-forming lipids to an aqueous solution comprising an antigen such that antigen-containing vesicles are formed, wherein in the step of adding the molten mixture of vesicle forming lipids is at a temperature of less than 120 C. In another aspect, the methods involve providing a molten mixture of vesicle-forming lipids and adding an aqueous solution comprising an antigen to the molten mixture of vesicle-forming lipids such that antigen-containing vesicles are formed, wherein the resulting mixture is placed under temperature-controlled conditions of less than 60 C. In yet another aspect, the methods involve providing a solution of vesicle forming lipids and adding the solution of vesicle-forming lipids to an aqueous solution comprising an antigen by injection such that antigen-containing vesicles are formed.
Variation Biotechnologies Inc. | Date: 2011-07-06
The present disclosure provides compositions and methods useful for treating influenza. As described herein, provided compositions and methods are based on the development of certain compositions that include an influenza virus hemagglutinin antigen in combination with lipid vesicles that include a non-ionic surfactant (NISVs) and optionally an adjuvant. In certain embodiments, provided compositions remain potent even when they are not stored in a standard cold-chain system (i.e., they are thermostable).