Timing of Vaccination After Training

Immune Response and Side Effects in Athletes

Tanja Stenger; Alexandra Ledo; Clemens Ziller; David Schub; Tina Schmidt; Martin Enders; Barbara C. Gärtner; Martina Sester; Timmeyer


Med Sci Sports Exerc. 2020;52(7):1603-1609. 

In This Article

Abstract and Introduction


Objectives: Influenza vaccination was used to assess whether induction of immunity or side effects are influenced by the timing of the last training session before vaccination.

Methods: Forty-five healthy athletes (36 male, 23 ± 8 yr, ≥5 training sessions per week, predominantly national competition level) were vaccinated with the tetravalent influenza vaccine; blood samples were collected immediately before and 1, 2, and 26 wk after vaccination. Athletes were randomly assigned to vaccination within 2 h after the last training session versus after 24–26 h. Influenza-specific T cells were quantified after stimulation with the vaccine based on intracellular cytokine staining. Antibodies (IgA, IgG, IgM) were quantified by enzyme-linked immunosorbent assay and neutralization assay. Participants documented resulting side effects and training restrictions using a standardized diary.

Results: Both groups showed an increase in influenza-reactive CD4 T-cell levels, which peaked 1 wk after vaccination (fold changes to baseline; median (interquartile range), 3.7 (3.0–5.4; P < 0.001) in the 2-h group; 4.6 (2.8–7.4; P < 0.001) in the 26-h group) with no difference between groups (P = 0.52). Influenza-specific antibodies showed a significant increase after vaccination in both groups (at least 1.4-fold, each P < 0.001, no group differences; P = 0.24–0.97 for different antibody types). Only antibodies toward the Brisbane strain showed a trend toward significant differences in neutralization titers between groups (4-fold (2–17.8) in the 2-h group, 16-fold (4–32.9) in the 26-h group; P = 0.06), whereas other specificities did not differ (P = 0.16–0.72). No intergroup differences were found for side effects; no athlete reported a loss of training time due to the vaccination or its side effects.

Conclusion: Infection prophylaxis in elite athletes by influenza vaccination seems to be effective and safe. Timing of vaccination after prior training does not seem to require specific constraints.


The prevention of infectious diseases is an important aspect of medical care in athletes. Besides avoiding exposure[1] and other hygienic measures,[2] vaccinations provide a powerful means for preventing a number of infectious diseases. In addition to a certain reluctance toward vaccination, which is obvious in the general population, vaccinations in elite athletes are often perceived to have specific problems and disadvantages. Even mild side effects may be of higher relevance for performance in an athlete population. Moreover, finding an acceptable time point for vaccination within tight training and competition schedules is a frequently discussed problem.[3,4] Despite some evidence that moderate exercise positively influences the immune response after vaccination, robust knowledge about interactions between timing of vaccination and regular training sessions in elite athletes is still lacking.[5]

The incidence of infections may be slightly higher in athletes because of high training loads,[6–8] travel,[9] and close contact to other athletes and staff members; psychological stress and athlete-specific lifestyle factors (nutritional needs, changing environment, etc) might also contribute. In this context, it has been suggested that this phenomenon may be related to changes in the number and function of lymphocytes in blood after heavy exercise or during competitions, which may increase susceptibility toward infectious agents ("open-window-theory"),[7,8,10] although this view has recently been challenged by the observation that training may rather lead to an enhancement of specific immunity after antigenic challenge.[11]

Consequently, the main aims of the present study were to address sport-specific aspects of vaccination and to contribute to developing a more rational basis for vaccination guidelines in competitive athletes.[12] We have previously reported that elite athletes show a more pronounced induction of vaccine-specific immunity as compared with nonactive controls.[13] Influenza has been chosen as the model vaccine because it is administered on a yearly basis, with the vaccine being specifically adapted to the currently circulating influenza strains. Therefore, many individuals can be considered naïve to the vaccine. Because of seasonality of disease and the availability of the vaccine, in the Northern hemisphere, this vaccination should be administered in the European autumn and therefore cannot easily be postponed to a period without training and competition. Finally, the vaccine is recommended for competitive athletes because influenza is highly contagious and influenza infection may give rise to severe complications (e.g., myocarditis), which compromise training efficacy and performance during competitions.[3] In this study, we focused on finding the most favorable time point for a vaccination with regard to the last training session. Based on the aforementioned considerations, we hypothesized that vaccination 26 h after training leads to a more pronounced immune response and less side effects than within only 2 h after training.