Vaccine Safety & Efficacy-Flu vaccine
Today we will look at a study about the efficacy and safety of the flu vaccine in infants. The study was published in The Pediatric Infectious Disease Journal in February 2010.
Englund JA, Walter E, Black S, Blatter M, Nyberg J, Ruben FL, Decker MD; GRC28 Study Team.
Study Summary- This was a double-blind, randomized, placebo-controlled trial, conducted in 1375 healthy US infants 6 to 12 weeks of age. Subjects received 2 doses of trivalent inactivated influenza vaccine (TIV, Fluzone, Sanofi Pasteur; N = 915) or placebo (N = 460) 1 month apart in combination with indicated concomitant vaccines. Solicited adverse events were collected for 7 days following vaccination, and unsolicited adverse events for 28 days. Antibodies to all 3 vaccine strains were measured following the second TIV/placebo dose.
Results – No significant differences were seen between TIV and placebo groups for any safety outcome. Fever > or =38 degrees C within 3 days of vaccination was seen in 11.2% versus 11.7% of TIV versus placebo recipients. Serious adverse events within 28 days were reported in 1.9% of TIV and 1.5% of placebo recipients. Antibody responses to childhood vaccines were similar in both groups. Increased influenza-specific antibody responses in TIV recipients compared with placebo recipients were seen against all 3 strains in TIV recipients, with better responses to influenza A strains noted. Reciprocal geometrical mean titer to H1N1, H3N2, and B were 33, 95, and 11 in TIV recipients versus 7, 9, and 5 for placebo recipients.
Conclusion – This study fulfills all the basic requirements for a well designed scientific study. The sample was large (1,375 participants); it was double-blind, randomized and placebo controlled. This study showed that the trivalent, inactivated flu vaccine was just as safe as the placebo and highly more efficient than placebo in inducing antibody response to all three strains of the virus. The authors concluded as such:
TIV administered to young infants beginning at 6 to 12 weeks of age is safe and immunogenic.