A Hidden Opponent:
Should Athletes Need Pneumococcal Protection?
Deepak Nagra¹˒³, Bako Nouri², Tim Blake¹, Maryam Adas³, Mark Russell³, James Galloway³
¹ Department of Rheumatology, University Hospitals Coventry & Warwickshire
² University Hospitals Manchester NHS Trust
³ Centre for Rheumatic Disease, King’s College London
Abstract
Background
Elite athletes are increasingly recognised as a population vulnerable to respiratory infections due to intense physical exertion, international travel, close-contact living environments, and exercise-induced immune dysregulation. Despite these recognised risks, pneumococcal vaccination is not routinely recommended for athletes within current United Kingdom travel immunisation guidance.
Methods
This commentary reviews existing evidence regarding respiratory infections among athletes, examines the immunological mechanisms that may increase susceptibility to pneumococcal disease, and evaluates current evidence supporting targeted vaccination strategies in elite sporting populations.
Results
Respiratory infections occur at an estimated rate of 4.7 infections per 1000 athlete days, with higher rates observed among non-elite athletes. Major international sporting events, including the Olympic and Paralympic Games, have reported substantial numbers of respiratory tract infections among participants. Studies have demonstrated exercise-related immune dysregulation, including reduced circulating memory T cells and upper airway dysbiosis, potentially increasing susceptibility to bacterial pathogens such as Streptococcus pneumoniae. Similar patterns of disease transmission have been observed in military cohorts exposed to comparable close-contact environments. The recent introduction of the 20-valent pneumococcal conjugate vaccine (PCV20) may provide expanded protection against emerging pneumococcal serotypes associated with antimicrobial resistance and outbreak potential.
Conclusions
Elite athletes represent a potentially under-recognised risk group for pneumococcal disease. Incorporating pneumococcal vaccination into pre-travel health assessments for athletes may offer an important preventive strategy, particularly for individuals participating in prolonged international travel, close-contact sporting environments, or intensive training schedules. Further research is needed to better characterise bacterial respiratory infections in athletes and inform future evidence-based vaccination policy.
Keywords
Pneumococcal vaccination; elite athletes; invasive pneumococcal disease; respiratory infections; sports medicine; immunisation; PCV20; travel health
Introduction
Respiratory infections remain a significant health concern within elite sport. Athletes are frequently exposed to factors that may increase susceptibility to infectious disease, including intense physical exertion, international travel, disrupted sleep patterns, close-contact living conditions, and repeated exposure to large crowds. Despite growing recognition of these vulnerabilities, invasive pneumococcal disease (IPD) remains under-recognised within sports medicine and public health guidance.
Current United Kingdom vaccination recommendations do not identify athletes as a specific risk group for pneumococcal vaccination. The UK Green Book does not currently include travelling athletes among the populations recommended for pneumococcal immunisation, despite increasing evidence suggesting that elite athletes may experience immune alterations and environmental exposures associated with heightened infection risk.
This commentary examines the current evidence regarding respiratory infections and pneumococcal disease risk among athletes, explores the immunological mechanisms that may contribute to increased susceptibility, and discusses the potential role of pneumococcal vaccination in athlete health protection strategies.
Respiratory Infections in Elite Athletes
Respiratory infections are among the most frequently reported illnesses affecting athletes during both training and competition. A systematic review examining respiratory illness in athletic populations reported an incidence rate of approximately 4.7 respiratory infections per 1000 athlete days, with even higher rates observed among non-elite athletes.
Large international sporting events have repeatedly documented substantial numbers of respiratory illnesses among participants. During the Rio 2016 Olympic Games, 346 respiratory tract infections were recorded among athletes. Similarly, respiratory infections represented approximately half of all illnesses reported during the London 2012 Paralympic Games. In beach volleyball athletes competing during the same Olympic period, 61% reported respiratory symptoms.
Despite the high prevalence of respiratory illness in sporting environments, most available literature has focused primarily on viral infections, while bacterial respiratory pathogens such as Streptococcus pneumoniae remain comparatively under-investigated.
Athletes are routinely exposed to conditions favourable to respiratory pathogen transmission, including shared accommodation, prolonged travel, commercial flights, communal dining facilities, and intensive close-contact training environments. These conditions may facilitate transmission dynamics similar to those observed in military settings, where outbreaks of pneumococcal disease have historically been documented.
Exercise-Induced Immune Dysregulation
The relationship between intense exercise and immune function has become an increasing area of interest within sports medicine. Emerging evidence suggests that strenuous physical activity may contribute to transient immune dysregulation, potentially increasing susceptibility to respiratory infections.
Studies involving Olympic athletes have demonstrated alterations in T-cell regulation and evidence of upper airway dysbiosis among athletes particularly vulnerable to respiratory illness. Reduced circulating memory T cells and disruption of the respiratory microbiome may impair mucosal immune defence mechanisms, facilitating colonisation by respiratory pathogens.
Additional contributing factors may include sleep deprivation, disrupted circadian rhythms associated with international travel, psychological stress, and inadequate recovery periods during intensive competition schedules.
These physiological and environmental stressors collectively create conditions in which respiratory pathogens, including pneumococcal bacteria, may spread more effectively within athlete populations.
Pneumococcal Disease and Vaccination Considerations
Although invasive pneumococcal disease is relatively uncommon among young healthy adults, outbreaks continue to occur globally, particularly within populations exposed to close-contact environments. Previous outbreaks among military recruits and university student cohorts illustrate the capacity of pneumococcal disease to spread rapidly in communal settings.
A notable outbreak reported among university students identified sports team participation as a potential risk factor. Importantly, the pneumococcal strain involved demonstrated atypical microbiological characteristics and could not initially be serotyped, highlighting the evolving epidemiology of pneumococcal disease.
The approval of the 20-valent pneumococcal conjugate vaccine (PCV20) by the Medicines and Healthcare products Regulatory Agency (MHRA) in 2025 represents an important development in pneumococcal prevention strategies. PCV20 offers expanded serotype coverage compared with previous polysaccharide vaccines, including protection against serotypes associated with increasing antimicrobial resistance and outbreak potential.
Despite these advances, vaccination strategies targeting athletes remain poorly developed. Existing sports medicine guidance has focused predominantly on viral respiratory illnesses, particularly following the COVID-19 pandemic, while bacterial respiratory pathogens have received comparatively limited attention.
The Case for Targeted Vaccination Strategies
The available evidence suggests that elite athletes may represent an under-recognised population vulnerable to respiratory infectious disease. Although current evidence remains limited, several factors support consideration of pneumococcal vaccination within athlete health assessments:
- Frequent international travel and exposure to diverse pathogens
- Close-contact accommodation and transport environments
- Exercise-induced immune alterations
- High transmission potential during major sporting events
- Increasing antimicrobial resistance among pneumococcal serotypes
Vaccination may be particularly relevant for athletes undertaking prolonged international travel, participating in major tournaments, residing in shared accommodation, or competing within resource-limited settings.
The inclusion of pneumococcal vaccination within pre-travel medical screening for athletes may therefore represent a practical preventive intervention capable of reducing respiratory illness burden and protecting athlete health.
Future Directions
Current literature examining pneumococcal disease specifically within athlete populations remains limited. Most available studies focus broadly on respiratory infections without detailed microbiological characterisation of causative organisms.
Further prospective research is needed to:
- Determine the true burden of bacterial respiratory infections among athletes
- Characterise pneumococcal carriage and transmission patterns in sporting environments
- Assess vaccine effectiveness within athletic populations
- Inform evidence-based vaccination recommendations for elite sport
Improved surveillance and targeted research will be essential for developing future public health guidance addressing respiratory infection prevention within the global sporting community.
Conclusion
Elite athletes may represent a vulnerable and under-recognised population at risk of respiratory infections, including pneumococcal disease. Intense training schedules, immune dysregulation, close-contact environments, and extensive international travel collectively contribute to conditions favourable for respiratory pathogen transmission.
Despite growing evidence regarding respiratory illness in sport, pneumococcal vaccination has not yet been systematically incorporated into athlete health protection strategies. The introduction of expanded conjugate vaccines such as PCV20 offers an opportunity to reconsider current preventive approaches.
Incorporating pneumococcal vaccination into pre-travel and pre-competition medical assessments may represent an important step towards improving respiratory health protection in elite athletes while supporting broader public health prevention efforts.
Open Access & Copyright
© 2026 The Authors. Published by the European Medical Specialist Review (EMSR) under the terms of the Creative Commons Attribution 4.0 International License (CC BY 4.0).
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