The change of 2 strains was expected but was not without considerable discussion.
The latest estimate of the overall effectiveness of this year's seasonal influenza vaccine puts it at just 19% (95% confidence interval [CI], 7%-29%), slightly lower than the 23% reported in mid-January, the Centers for Disease Control and Prevention (CDC) reported yesterday.
Faced with new data, the ACIP drops its preference for nasal-spray flu vaccine in 2- to 8-year-olds.
The World Health Organization (WHO) today recommended changing two of the three strains in trivalent flu vaccines for use in the Northern Hemisphere's 2015-16 flu season.
A Scottish study of this year's vaccine found effectiviness of 33%, higher than elsewhere.
An additional case of H7N9 avian flu in China's Guangdong province has been reported to Hong Kong's Centre for Health Protection (CHP), according to a machine-translated statement posted today by FluTrackers, an infectious disease news message board.
A study based on data from more than 2 million Medicare beneficiaries suggests that the high-dose influenza vaccine works better than a standard-dose vaccine for preventing probable flu illness and flu-related hospital admissions in elderly people.
Researchers in both places found vaccine effectiveness to be well below the already-low US numbers.
Influenza seems reluctant to release its grip on the United States, as most measures of flu activity showed little change last week, according to today's update from the Centers for Disease Control and Prevention (CDC).
This flu season's vaccine has provided "little or no protection" against influenza in Canada because of a mismatch between the H3N2 strain included in the vaccine and the predominant circulating H3N2 strain, say interim findings from the Canadian Sentinel Physician Surveillance Network (SPSN) published in today's issue of Eurosurveillance.
