Monitoring the population effectiveness of pneumococcal conjugate vaccination in the Finnish national vaccination programme

Duration:

1.1.2011–31.12.2020

Unit at THL:

Impact Assessment Unit

On other websites:

Background

Pneumococcal conjugate vaccines have been shown to reduce the burden of disease caused by Streptococcus pneumoniae. In addition to providing direct protection to the vaccinated children, the vaccine also provides indirect protection forof unvaccinated children and adults. The vaccine currently used in Finland is marketed under the name Synflorix. Synflorix does not contain live bacteria and, hence, cannot cause pneumococcal disease.

In the U.S., where since 2000 infants have been vaccinated against Streptococcus pneumoniae, the incidence of invasive pneumococcal disease (IPD) has decreased considerably in all age groups. Furthermore, hospitalization rates for pneumonia have markedly decreased in the United States after the introduction of pneumococcal vaccine into the national vaccination programmeplan (NVP) among children under the age of 2 years and also among adults aged 18 to 39 years. However, in some regions the incidence of diseases caused by pneumococcal serotypes other than those covered by the vaccine has increased.

In Finland, the pneumococcal conjugate vaccine for children was introduced into the national vaccination programme in 2010. The two prime doses are administered at the ages of 3 and 5 months, and a booster dose at 12 months. The vaccines are administered concomitantly with other vaccinations in the national vaccination programme.

Goals

The purpose of this study is to assess the overall public health benefits of the pneumococcal vaccination programme. The following four outcomes are monitored for the population effectiveness:

  • Invasive pneumococcal disease;
  • Hospital-diagnosed pneumonia;
  • Tympanostomy tube placement; and
  • Outpatient treatment with antimicrobial agents

Implementation

The National Institute for Health and Welfare (THL) monitors the epidemiology of invasive pneumococcal diseases, and the incidence of pneumonia and acute otitis media (AOM) through national health registers and enhanced surveillance.

The existing surveillance systems and data sources for pneumococcal disease are listed below.

  • The National Infectious Diseases Register maintained by the National Institute for Health and Welfare (THL) (previously the National Public Health Institute, KTL) since 1995
    • Invasive pneumococcal diseases including serotyping and antimicrobial resistance
  • The national Care Register maintained by the National Institute for Health and Welfare (THL) (previously the National Research and Development Centre for Welfare and Health, STAKES) since 1994

  • Hospital-diagnosed pneumonia (ICD-10)

  • Tympanostomy tube placement (performed in public health care)

  • The benefits register of the Social Insurance Institution of Finland (KELA)

  • Tympanostomy tube placement in private health care (since 1964)

  • Prescriptions of antimicrobial agents (since 1995, and in its current form since 2006)

Enhanced surveillance

The enhanced surveillance system covers all children eligible for the national pneumococcal conjugate vaccination programme. Vaccination information is verified from the medical records at primary health care when a notification of invasive pneumococcal diseases is entered into the National Infectious Diseases Register (NIDR). To avoid unnecessary delays, the serotyping of pneumococci which have caused invasive pneumococcal diseases in children is prioritised at laboratories.

The total effect of the national vaccination programme (i.e. the sum of direct and indirect effect) is assessed for children born after 1 June 2010. Indirect effect is assessed in children born before 1 June 2009 and stratified by age. Based on subsequent data, further risk group stratifications, such as low birth weight, will be performed.

Children born between June 2009 and May 2010 have largely been eligible for the FinIP trial, and will, thus, mainly be evaluated in the trial setting. Click here for more information on the FinIP trial

Timetable

Monitoring the effectiveness impact of pneumococcal conjugate vaccination began in 2012, and is ongoing. The results of the effectiveness impact surveillance are published annually by the National Institute for Health and Welfare (THL). Due to the relatively small birth cohorts in Finland, it is expected that reliable data from subgroup analysis can only be achieved after several years of surveillance.

Coordination and funding

The study is coordinated and funded by the National Institute for Health and Welfare (THL). The working group includes researchers from the Department of Vaccination and Immune ProtectionHealth Protection and the Department of Infectious Diseases Surveillance and Control.

Updated: