Lack of evidence for complete resistance of peripheral blood mononuclear cells to HIV-1 and HIV-2 infection.

There are reports that not all individuals exposed to HIV-1 become infected and the possibility exists that some individuals may be completely resistant to infection with this virus. This study aims to investigate, in vitro, whether certain peripheral blood mononuclear cells (PBMCs) are completely resistant to HIV-1 and HIV-2 infection. PBMCs obtained from 130 unrelated healthy HIV-1- and HIV-2-seronegative volunteers were infected with four different isolates of HIV-1 (H995 and MN) and HIV-2 (CBL-20 and ROD) using several multiplicities of infection.

A plant-produced influenza subunit vaccine protects ferrets against virus challenge.

Background: Influenza A viruses are of major concern for public health, causing worldwide epidemics associated with high morbidity and mortality. Vaccines are critical for protection against influenza, but given the recent emergence of new strains with pandemic potential, and some limitations of the current production systems, there is a need for new approaches for vaccine development.

Objective: To demonstrate the immunogenicity and protective efficacy of plant-produced influenza antigens.

In vivo prophylactic activity of QR-435 against H3N2 influenza virus infection.

Background: Prophylaxis against influenza infection can take several forms, none of which is totally effective at preventing the spread of the disease. QR-435, an all-natural compound of green-tea extract and other agents, has been developed to protect against a range of viral infections, including the influenza subtype H3N2.

Methods: Several different QR-435 formulations were tested against the two influenza A H3N2 viruses (A/Sydney/5/97 and A/Panama/2007/99) in the ferret model.

Preclinical in vitro activity of QR-435 against influenza A virus as a virucide and in paper masks for prevention of viral transmission.

Prophylaxis against influenza is difficult, and current approaches against pandemics may be ineffective because of shortages of the two proven classes of antivirals in the face of a large-scale infection. Herbal/natural products may represent an effective alternative to conventional attempts to protect against infection by avian influenza virus. QR-435, an all-natural compound of green tea extract and other agents, has been developed to provide protection against a wide range of viral infections.

A throat lozenge containing amyl meta cresol and dichlorobenzyl alcohol has a direct virucidal effect on respiratory syncytial virus, influenza A and SARS-CoV.

A potent virucidal mixture containing amyl metacresol and dichlorobenzyl alcohol at low pH inactivated enveloped respiratory viruses influenza A, respiratory synctial virus (RSV) and severe acute respiratory syndrome coronavirus (SARS-CoV) but not viruses with icosahedral symmetry, such as adenoviruses or rhinoviruses. A titre of approximately 3.5 log10 TCID50 was reduced to below the level of detection within two minutes.

New antiviral drugs, vaccines and classic public health interventions against SARS coronavirus.

Severe acute respiratory syndrome (SARS) is caused by one of two recently discovered coronaviruses. The virus is emergent from South East (SE) Asian mammals: either the civet cat, a related species or a rat species. The virus has a long incubation period and low reproduction number (R0 value) and hence the first outbreak in 2004 was controlled by hygiene and quarantine.

Human genetics and responses to influenza vaccination: clinical implications.

Influenza A and B viruses are negative-strand RNA viruses that cause regular outbreaks of respiratory disease and substantially impact on morbidity and mortality. Our primary defense against the influenza virus infection is provided by neutralizing antibodies that inhibit the function of the virus surface coat proteins hemagglutinin and neuraminidase. Production of these antibodies by B lymphocytes requires help from CD4+ T cells.

Non-responders to egg grown influenza vaccine seroconvert after booster immunization with MDCK cell grown vaccine.

We have investigated whether 'at risk' subjects who did not respond serologically during a pre-study vaccination with a commercial egg grown influenza sub-unit vaccine would respond to a subsequent vaccination with either a single dose of MDCK cell grown influenza vaccine or a standard egg grown influenza vaccine containing the same virus strains. We studied 48 non-responder subjects with a mean age 67.5, range: 34-82 years.

New millennium antivirals against pandemic and epidemic influenza: the neuraminidase inhibitors.

The mushroom shaped outer spike protein of influenza, neuraminidase, was first discovered nearly 60 years ago. Its importance in viral replication was soon recognised both at the point of viral release from the cell and also enabling passage of virus through nasal fluid to reach the cell. The enzyme active site was identified by x-ray crystallography, allowing an atomic study of interaction of enzyme with the sialic acid substrate.