Jul 19, 2011
Adult flu vaccine doses better protect infants
Giving infants full rather than half doses of seasonal influenza vaccine improves immunogenicity, Canadian researchers reported yesterday in Pediatrics. The randomized controlled trial at three centers included 252 participants in two age-groups: infants from 6 months to less than 1 year old and toddlers age 12 to 23 months. It was conducted between Sep 1 and Dec 21, 2008. The researchers compared the lower 0.25-mL dose typically given twice in North America with the full adult 0.5-mL dose given in two doses to young children in other countries. Researchers collected serum samples for antibody measurement at baseline and 27 and 45 days after the second dose. For infants who received the full doses, seroprotection rates were 10% higher than for those who received half doses, thus meeting the criterion for superiority. For toddlers, seroprotection rates exceeded 85% in both dosing groups and the higher-dose group had higher seroprotection rates but not high enough to achieve superiority. No difference in fever rates was seen between the two dosing groups, and parent acceptability rates were comparable. The researchers concluded that more dosing studies are needed, but that the findings suggest a way to improve protection in infants, a group at high risk for flu complications.
Jul 18 Pediatrics abstract
Study: Adjuvanted pandemic vaccine protected Germans well
Two different methods of calculating vaccine effectiveness showed that the adjuvanted pandemic H1N1 vaccine used in Germany provided good protection, especially in children under age 14, according to a report in PLoS One. German researchers used the test-negative case-control method, in which they compared vaccination rates in patients who tested positive or negative for the pandemic virus by RT-PCR after the vaccine containing the adjuvant AS03 became available. This method indicated the vaccine was 79% effective in children younger than 14 and 70% in people older than 14. The other method was what the authors describe as a novel case-series approach, in which they looked at all nationally reported confirmed pandemic flu cases. They identified cases in people who were vaccinated and compared the proportion of cases that occurred during an assumed unprotected period immediately after vaccination with the proportion that occurred later, during the assumed protected phase. This method indicated the vaccine was 87% effective in children under 14 and 74% effective for older individuals. But the authors say the case-series method is prone to potential biases affecting the case count during the unprotected period, such as if doctors tend to test patients in the 2 weeks after vaccination more than in the later protected period.
Jul 18 PLoS One report
States allowing raw milk sales hold steady
The number of states that allow raw milk sales is the same as 3 years ago, according to a report today from Food Safety News (FSN) on a new survey from the National Association of State Departments of Agriculture (NASDA). Thirty states allow raw milk sales, while 20 do not. Five states, however, have passed stricter bacteria standards for raw milk: Idaho, New Hampshire, Pennsylvania, South Dakota, and Vermont. The survey was conducted between Apr 22 and Jun 30 with assistance from the National Association of Dairy Regulatory Officials. NASDA's public policy director told FSN that the groups usually conduct the raw milk survey every 4 years, but they did the latest one a year early because of the newly passed Food Safety Modernization Act and because several states have tried to change their raw milk laws.
Jul 19 FSN story
Study: Some chikungunya patients have long-term rheumatic pain
A study of 509 chikungunya cases in India showed that, although two-thirds of patients recovered within 4 weeks, 4% suffered from persistent rheumatic pain 1 year after infection. Researchers from the Centre for Rheumatic Diseases in Pune studied cases from a 2006 epidemic in a West India village, where the attack rate was 43%. More than 90% of the patients had high fever, severe peripheral multi-joint pain, intense fatigue, and axial muscle pain—common symptoms of the mosquito-borne disease. Sixty-five percent of patients recovered within 4 weeks, and none of the patients died. However, 4.1% had persistent rheumatic pain 1 year later, and 1.6% had such pain after 2 years. Chronic inflammatory arthritis, in contrast, was present in only 0.3% of patients after 1 year.
Jul 18 Epidemiol Infect abstract