Response to the letter to the Editor regarding the article “Vaccine versus infection - COVID-19-related loss of training time in elite athletes”

• Published in: Journal of science and medicine in sport Vol. 26; no. 3; pp. 181 - 182
• Main Authors: Krzywański, Jarosław, Mikulski, Tomasz, Krysztofiak, Hubert, Pokrywka, Andrzej, Sobierajski, Tomasz, Młyńczak, Marcel, Piechuta, Aleksandra, Kuchar, Ernest
• Format: Journal Article
• Language: English
• Published: Australia Elsevier Ltd 01.03.2023; Elsevier Limited; Sports Medicine Australia. Published by Elsevier Ltd
• Subjects: Athletes; Clinical trials; Confounding (Statistics); Coronaviruses; COVID-19 - prevention & control; COVID-19 vaccines; Humans; Infections; Letter to the Editor; Medical personnel; Medical research; Severe acute respiratory syndrome coronavirus 2; Sports - physiology; Vaccines
• ISSN: 1440-2440; 1878-1861; 1878-1861
• DOI: 10.1016/j.jsams.2023.02.007

In particular, they believe that the absence of clinical symptoms after vaccination may be associated with previous asymptomatic SARS-Cov-2 infection, and undiagnosed COVID-19 at the time of vaccination may cause the observed side effects and affect the loss of training after vaccination, not the vaccination itself. In the study cited in the letter, which included healthcare workers caring for COVID-19 patients, postvaccination SARS-CoV-2 infection occurred within 14 days of the initial dose in 67 of 7109 (0.9%).6 These rates are up to five times lower in the clinical trials cited above.2,3 Even if, in a few cases, we incorrectly classified the disease symptoms as adverse effects of vaccination, this bias would not work in favor of vaccines. The studies on the association between host genetics and SARS-CoV-2 infection have identified many DNA variants associated with COVID-19, but this is only the starting point to explain the mechanisms underlying the immune response.7Funding information This research did not receive any specific funding.Confirmation of ethical compliance The authors declare that the Bioethics Committee at the Medical University of Warsaw on October 4, 2021, received information about the subject of the study entitled “Assessment of young athletes' attitudes towards vaccinations against COVID-19 and their impact on the implementation of the training program.”