BACKGROUND Understanding immunity, incidence and risk factors of the 2009 influenza A(H1N1) pandemic (2009 H1N1) through a national seroprevalence study is necessary for informing public health interventions and disease modelling. METHODS AND FINDINGS We collected 1687 serum samples and individual risk factor data between November-2009 to March-2010, three months after the end of the 2009 H1N...

BACKGROUND A common pattern emerging from several studies evaluating the impact of the 2009 A/H1N1 pandemic influenza (A/H1N1pdm) conducted in countries worldwide is the low attack rate observed in elderly compared to that observed in children and young adults. The biological or social mechanisms responsible for the observed age-specific risk of infection are still to be deeply investigated. ...

Haemagglutination inhibition tests are easy to perform and easy to read. The results are reproducible and are not subject to the vagaries of supply and temperament inherent in tests using living creatures. In a series of tests with Prepuerin done in parallel with the Hogben test the former has shown a higher sensitivity. There have been three false positive results with Prepuerin tests in the s...

OBJECTIVE To evaluate the relationship between measles virus (MV) antibodies (abs) in sera and breast milk of nursing mothers, their contributions in seroconversion of children (0-9 months) post vaccination, prevalence of prevaccination measles abs in sera of children brought for measles vaccination and seroconversion rate in vaccinees from nursing and lactating mothers. Also to determine the p...

BACKGROUND Mainland China experienced pandemic influenza H1N1 (2009) virus (pH1N1) with peak activity during November-December 2009. To understand the geographic extent, risk factors, and attack rate of pH1N1 infection in China we conducted a nationwide serological survey to determine the prevalence of antibodies to pH1N1. METHODOLOGY/PRINCIPAL FINDINGS Stored serum samples (n = 2,379) collec...

Ten antisera were produced in rabbits by two or three intravenous injections of inactivated whole influenza type A virions. All contained haemagglutination-inhibition (HI) antibody directed predominantly to an epitope in antigenic site B and, in addition, various amounts of antibodies to an epitope in site A and in site D. The ability of untreated antisera to select neutralization escape mutant...

OBJECTIVES To compare serological response to influenza vaccine in patients with long-standing rheumatoid arthritis (RA) treated with tumour necrosis factor (TNF) blockers and/or methotrexate (MTX) and controls. METHODS Altogether, 149 patients with RA and 18 healthy subjects were vaccinated. Fifty patients were treated with TNF blockers (etanercept or infliximab) in combination with MTX (TNF...

OBJECTIVES The HPAI H5N2 strain that caused an outbreak in ostriches of the Eastern Cape Province, South Africa in 2004 was characterized. DESIGN Haemagglutination inhibition (HI) and agar gel immunodiffusion (AGID) were performed on sera from ostrich farms in the outbreak region, and intravenous pathogenicity (IVPI) tests, reverse-transcriptase-polymerase-chain reaction (RT-PCR), nucleic aci...

Radial haemolysis (RH) for assaying rubella antibody was studied in parallel tests with haemagglutination-inhibition (HAI) on 1102 sera from adult women. Simple to perform and economical in reagents, the RH test is as sensitive as the HAI test and is a useful method of screening antenatal and other sera for rubella immunity. It detects IgG but not IgM antibody.

BACKGROUND Older individuals often have a reduced immune response to influenza vaccination, which might be improved by administering a higher vaccine dose. We compared the immune response to two single doses of the AS03A-adjuvanted H5N1 pandemic vaccine (3.75 μg hemagglutinin of A/Vietnam/1194/2004) with that of two double vaccine doses (7.5 μg hemagglutinin) in adults aged ≥61 years. Here we r...