US regulators have expanded the scope of Pfizer's pneumococcal vaccine Prevnar 13, allowing its use in adults aged 18 to 49 years of age.

Prevnar 13 (Pneumococcal 13-valent Conjugate Vaccine [Diphtheria CRM197 Protein]) is already approved for adults 50 years and older to prevent of pneumonia and invasive disease caused by 13 Streptococcus pneumoniae serotypes.

The vaccine is also cleared for immunisation of children aged 6 weeks through 17 years, making it the only one approved across the entire lifespan.

The expanded age indication in adults 18 to 49 "offers an important public health benefit as appropriate vaccination against S. pneumoniae is critical to reducing the risk of pneumococcal disease, including in those with immunocompromising conditions," said Dr Luis Jodar, chief medical and scientific affairs officer at Pfizer Vaccines.

S. pneumoniae, also known as pneumococcus, is the most common bacterial cause of community-acquired pneumonia. While non-invasive forms of pneumococcal disease are typically more common, the invasive types of disease are generally more severe, the firm noted.