Cases of pneumonia among children in Kilifi have reduced sharply after the introduction of a vaccine in 2011, latest results show. The pneumococcal vaccine was introduced in Kenya in 2011 mostly to prevent pneumonia and meningitis. Ministry of Health and KEMRI-Wellcome Trust Research Programme have been monitoring reported cases at the Kilifi District Hospital (KDH) to see if the vaccine is effective. Latest results seen by the Star show cases dropped by more than 90 per cent last year compared to 2003 when there was no vaccine. "However, the 8 baseline years show considerable variation in the number of cases year-on-year and it will take several years to be confident that changes in disease frequency are attributable to vaccine," says the study, which ends later this year. Kenya vaccinates about 1.3 million children under five every year with the Pneumococcal vaccine (pneumococcal conjugate vaccine, PCV10), costing about Sh2 billion. The country pays only Sh80 million and the balance is cleared by Gavi Alliance, a donor consortium who are also funding the five-year study. The study proves the Gavi and Kenya are spending their money effectively. "The cost-effectiveness of the vaccine program will be calculated based on the costs of vaccine introduction, the costs of treatment averted, and the changes in incidence observed," said Kemri-Wellcome Trust in its report. Pneumonia is currently the biggest killer of Kenyan children under five years. The survey compares the incidence rates of invasive pneumococcal disease, radiologically proven pneumonia, and all-cause admissions to hospital in the period before vaccine introduction and the period after vaccine introduction. It also assesses the safety of the vaccine at four sites. These are the Kilifi HDSS, the KEMRI CDC Research and Public Health Collaboration International Emerging Infections Program surveillance sites in Kibera and Rarieda District and the KEMRI/CDC HDSS site in Siaya District. "In August 2013, an end of study report was submitted to WHO, the study did not provide evidence that introduction of PCV10 in Kenya has increased the risk of abscess, shock or death following immunisation," researchers said. However, for a more refined evaluation of risk, continued surveillance was recommended.