Invasive pneumococcal disease in 2025
Annual report on invasive pneumococcal disease in 2025
Statens Serum Institut (SSI) monitors the occurrence of invasive pneumococcal disease (IPD) in Denmark (Executive Order on the Notification of Infectious Diseases). Surveillance has existed in its current form since 2007, when vaccination against pneumococci was introduced in Denmark. Surveillance contributes to the ongoing assessment of the effectiveness of the pneumococcal vaccination programme.
In practice, surveillance is conducted by the departments of clinical microbiology (DCMs) sending pure bacterial isolates of pneumococci (Streptococcus pneumoniae) to SSI if the bacterium has been detected in normally sterile sample material (blood, cerebrospinal fluid, synovial fluid, pleural fluid, etc.). SSI also obtains additional information from the Danish Microbiology Database (MiBa), for example in cases where only bacterial DNA could be detected and an isolate is therefore not available.
The isolates submitted to SSI undergo, among other things, serotyping. Serotyping is essential for continuously assessing the suitability of different types of pneumococcal vaccines, as different vaccines protect against different serotypes. There are more than 100 different serotypes of pneumococci, and each of the available vaccines protects against a number of the serotypes that most frequently cause disease in humans.
Antibiotic resistance in pneumococci is monitored through the DANMAP collaboration.
Invasive pneumococcal disease (IPD) occurs in all age groups and is a serious infection in which pneumococcal bacteria are found in normally sterile sites such as blood, cerebrospinal fluid, synovial fluid or pleural fluid. IPD can be fatal and may, among other things, occur as a consequence of severe pneumonia caused by pneumococcal bacteria. IPD occurs throughout the year, but with a markedly increased occurrence during the winter months. Age groups at particular risk of IPD are children under 2 years of age, persons aged 65 years and over, as well as persons with chronic disease.
In 2025, 83 persons (12%) were registered as having died within 30 days after detection of IPD. The cause of death is presumably associated with IPD, but further details are not known. In 2023 and 2024, the corresponding figures were 88 (14%) and 90 (14%) deaths. The proportion of deaths associated with IPD was thus slightly lower in 2025 compared with previous years.
In 2007, free vaccination against pneumococci was introduced into the childhood vaccination programme. Persons over 2 years of age at increased risk of IPD also have the option of pneumococcal vaccination at their own expense. However, conditional reimbursement for vaccination may be granted to certain groups. Read more in the section on vaccination below.
Increasing incidence of invasive pneumococcal disease in 2025
In 2025, 710 cases of invasive pneumococcal disease were registered among persons with a Danish civil registration (CPR) number. Of these, 339 were women (48%) and 371 were men (52%).
This is an increase compared with 2023 and 2024, when 625 and 614 cases were registered, respectively. Before vaccination against pneumococci was introduced into the childhood vaccination programme in 2007, just over 1,000 cases were typically registered annually.
The age distribution and incidence by age group in 2025, as well as corresponding data for 2023 and 2024, are shown in Table 1. The age distribution for 2025 is shown in Figures 1a and 1b, and the incidence by age group since 2000 is shown in Figure 2.
The number of IPD cases in 2025 was slightly higher than the number in 2024. This was mainly due to a small increase in each of the three most predominant serotypes: 3, 8 and 9N.
In 2024, there was an increased number of IPD cases among children aged 0–1 year, EPI-NEWS 47/2025. The increase was mainly due to a high occurrence of serotype 38. This pattern was not observed in 2025.
Figure 2. Incidence of invasive pneumococcal disease in Denmark, by age group, 2000–2025. Arrows indicate the introduction of the PCV7, PCV13 and PCV15 vaccines, respectively, into the childhood vaccination programme.
Of the 710 cases of IPD in 2025, 614 involved detection of pneumococci in blood (86%), 82 involved detection in cerebrospinal fluid (12%), and 14 were from other sample material (corresponding to 2.0%; eight from pleural fluid, five from synovial fluid and one from the peritoneum). The distribution of sample material was very similar to that of the previous two years, Table 2.
The occurrence of invasive pneumococcal disease is primarily during the winter period and extends slightly into spring. The number of registered cases per month from 2023 to 2025 is shown in Figure 3.
Serotypes of pneumococci in invasive pneumococcal disease in 2025
There are more than 100 different subtypes, called serotypes, of pneumococci. Some frequently cause infections, others more rarely. Pneumococcal vaccines are therefore designed to cover common types. Following the introduction of pneumococcal vaccination into the childhood vaccination programme, there has been a clear decrease in the serotypes covered by the childhood vaccine. In 2007, a vaccine that protected against seven types (PCV7) was introduced. In 2010, it was replaced by a vaccine that protected against thirteen types (PCV13). In November 2025, we switched to a vaccine that protects against fifteen types (PCV15), EPI-NEWS 48/2025. For risk groups, it is also possible to use vaccines that protect against 20 or 21 serotypes, respectively.
Previously, another type of vaccine was also available for risk groups, which protected against 23 serotypes, but it has now been discontinued, EPI-NEWS 27-33/2026.
Figure 4 shows how many of the IPD serotypes in 2025 are included in the different available pneumococcal vaccines. The figure does not indicate whether the individual patients have been vaccinated or not.
Figure 5 shows the proportion of serotypes included in the PCV7 and PCV13 vaccines, respectively, from 2004 up to and including 2025. The decrease resulting from the introduction of the vaccine is clearly visible. The figure does not indicate whether the individual patients have been vaccinated or not.
Pneumococcal disease can be prevented through vaccination
The childhood vaccination programme
In 2007, pneumococcal vaccination was introduced into the childhood vaccination programme at 3, 5 and 12 months of age. The vaccine is therefore given at the same time as the diphtheria-tetanus-pertussis-polio-Hib vaccine. The first pneumococcal vaccine used protected against seven serotypes (Prevenar), and in 2010 it was replaced by a vaccine that protected against thirteen serotypes (Prevenar13). Since November 2025, a vaccine that protects against 15 serotypes (Vaxneuvance) has been used. Vaccination coverage is 96% for the two most recent fully vaccinated birth cohorts (2023 and 2024).
As the vaccine does not protect against all serotypes of pneumococci, a child may still develop invasive pneumococcal disease even if fully vaccinated. In rare cases, this may also be due to actual vaccine failure.
Pneumococcal vaccines for other groups
Persons at increased risk of severe pneumococcal disease may consider being vaccinated against pneumococci. Persons aged 65 years and over and persons with chronic disease are among those at increased risk. Read more about risk groups and recommendations in the guidance here.
The guidance states that a choice can be made between two vaccines (Prevenar20 and Capvaxive). These vaccines protect against the serotypes that most frequently cause severe disease in adults, as described above. When choosing a pneumococcal vaccine, several factors may play a role – e.g. price, eligibility for conditional reimbursement, the breadth of vaccine coverage and the need for revaccination. The vaccine is given as a single dose. Previously, another type of vaccine was used, for which revaccination was necessary every 6 years. This vaccine has now been discontinued (Pneumovax).