Pneumococcal vax cuts deaths, but cases tripled

It's not often that we report on a doctoral thesis here at FierceVaccines, but this one has hit the headlines--while vaccines against Streptococcus pneumoniae have cut the number of deaths from this bug that can cause pneumonia and meningitis, the number of cases has tripled in the past 50 years.

The thesis, written by Erik Backhaus, doctoral student, Sahlgrenska Academy, University of Gothenburg, looked at the changes in invasive pneumococcal disease before and after the introduction of childhood vaccination with the 7 valent pneumococcal conjugate vaccine known as PCV-7 in Sweden. He collected samples and medical information from adults and children with serious disease between 1998 and 2001, and looked at the serotype of the bug and whether it was resistant to antibiotics. He found that the number of cases had risen from 5 to 15 per 100,000 inhabitants per year, and that while the risk of dying varied between age groups and state of health, the overall chance of dying from this bug has halved, from 20 percent to 10 percent.

Pneumococcal disease kills around a million children worldwide every year. There are two main types of vaccines currently available--conjugate vaccines that are suitable for infants but protect against fewer strains of pneumococcal bacteria (around 70%), and polysaccharide vaccines that can only be given to children over the age of two, but protect against more bacterial strains (around 95 %). According to Backhaus, this means that the polysaccharide-based shots miss those who need it most.

This is not the ideal situation, and shows an unmet need, and perhaps a gap in the market for a vaccine developer. In the meantime, though, pneumococcal vaccines are entering new markets, and standard vaccination programs are beginning to include pneumococcal vaccination, which should have the two-fold effect of reducing infections in both children and adults.

- here's more news
- read the press release on the research
- see the abstract and paper (PDF)