From 2013 an annual nasal live-attenuated influenza vaccine (LAIV—Fluenz) is available for all children in the UK aged 2 and 3 years and other ‘at-risk’ children, as part of the National Health Service (NHS) childhood vaccination programme. 2 The vaccine contains reassortant influenza viruses; two influenza A viruses (H1N1 and H3N2) and one influenza B virus, and has previously been used in chi...

BACKGROUND In most seasons, the influenza vaccine is effective in preventing influenza, but it is not clear whether it is equally effective in preventing mild and severe cases. We designed a case-control study to compare the effectiveness of the influenza vaccine in preventing outpatient, inpatient, and severe or fatal cases of laboratory-confirmed influenza. METHODS Hospitalized patients (n ...

BACKGROUND Millions of doses of influenza vaccine are administered each year in the United States at nontraditional sites and by nontraditional vaccine providers. Pharmacists are increasingly becoming vaccine providers. OBJECTIVES To measure association between availability of pharmacist-immunizers and immunization delivery to adult prescription recipients, and the relative contributions of v...

BACKGROUND Although vaccination with trivalent inactivated influenza vaccine (TIV) is recommended for all pregnant women, no vaccine effectiveness (VE) studies of TIV in pregnant women have assessed laboratory-confirmed influenza outcomes. METHODS We conducted a case-control study over 2 influenza seasons (2010-2011 and 2011-2012) among Kaiser Permanente health plan members in 2 metropolitan ...

BACKGROUND Influenza in children causes significant morbidity and hospitalizations and also some mortality particularly in children < 5 years of age. Influenza vaccination in children has been shown to be safe and effective, but in 2010 the pediatric influenza vaccination program was suspended in Western Australia after the rate of febrile convulsions observed (9/1000 doses) was 55 times the pr...

OBJECTIVE Intranasal influenza vaccine has proven clinical efficacy and may be better tolerated by young children and their families than an injectable vaccine. This study determined the potential cost-effectiveness (CE) of an intranasal influenza vaccine among healthy children. METHODS We conducted a CE analysis of data collected between 1996 and 1998 during a prospective 2-year efficacy tri...

Following the global spread of pandemic influenza A(H1N1)2009, several pandemic vaccines have been rapidly developed. The United Kingdom and many other countries in the northern hemisphere implemented seasonal and pandemic influenza vaccine programmes in October 2009. We present the results of a case–control study to estimate effectiveness of such vaccines in preventing confirmed pandemic influ...

A number of studies have reported that influenza vaccine (IV) administration has been less than optimally effective in certain subpopulations. This study examines yearly influenza death rate, yearly influenza case rate, and yearly rate of hospitalizations with influenza as the first-listed discharge diagnosis. By these measures, the yearly U.S. mass influenza vaccination campaign has been ineff...

Influenza illness is caused by influenza A and influenza B strains. Although influenza A viruses are perceived to carry greater risk because they account for the majority of influenza cases in most seasons and have been responsible for influenza pandemics, influenza B viruses also impose a substantial public health burden, particularly among children and at-risk subjects. Furthermore, since the...

We define a new parameter to quantify the antigenic distance between two H3N2 influenza strains: we use this parameter to measure antigenic distance between circulating H3N2 strains and the closest vaccine component of the influenza vaccine. For the data between 1971 and 2004, the measure of antigenic distance correlates better with efficacy in humans of the H3N2 influenza A annual vaccine than...