Regulators in the USA have given the green light to Pfizer’s new version of the blockbuster childhood vaccine Prevnar.

The US Food and Drug Administration has granted approval for Prevnar 13 for the immunisation of infants and young children for the prevention of invasive disease caused by 13 Streptococcus pneumoniae serotypes (1, 3, 4, 5, 6A, 6B, 7F, 9V, 14, 18C, 19A, 19F, and 23F). The vaccine, which Pfizer got hold of through its recent acquisition of Wyeth, is also indicated for the prevention of otitis media caused by serotypes 4, 6B, 9V, 14, 18C, 19F, and 23F.

Invasive pneumococcal disease includes sepsis and bacteremia, meningitis, bacteremic pneumonia and empyema, which is the accumulation of pus in the cavity surrounding the lungs. The approval is based on the review of 13 Phase III studies involving more than 7,000 infants and young children.

The FDA was due to give its final decision on Prevnar 13 by December 30, having already extended its review by 90 days from an original action date of September 30. based on the submission of additional manufacturing data. As part of the approval, Pfizer has agreed to certain post-marketing commitments including a study to further evaluate the safety profile of Prevnar 13, a trial to look at the prevention of overall invasive pneumococcal disease and various studies to evaluate reduction in otitis media.

Geno Germano, head of the New York-based drug giant’s specialty care business unit, said the approval is a significant milestone, saying it is “an important priority for the entire Pfizer organisation as we continue to expand our presence in the vaccine category”. Analysts believe that by 2012, sales of Prevnar 13, which was approved in Europe two months ago, could surpass those of the original seven-serotype version, which contributed $287 million to Pfizer’s coffers in just the last two months of 2009.