tetano
Editor, Senior Moderator
J Infect Chemother
. 2025 Aug 18;31(10):102798.
doi: 10.1016/j.jiac.2025.102798. Online ahead of print. The effectiveness of repeated vaccination for COVID-19 symptom resolution during the KP.3-dominant epidemic period in Japan: A retrospective multicenter study
Takuma Bando[SUP] 1 [/SUP], Hideyuki Ikematsu[SUP] 2 [/SUP], Naoki Kawai[SUP] 2 [/SUP], Keigo Shibao[SUP] 2 [/SUP], Masayuki Mizuguchi[SUP] 2 [/SUP], Tokunao Amemiya[SUP] 2 [/SUP], Satoshi Tsuchiya[SUP] 2 [/SUP], Yoshitaka Oribe[SUP] 2 [/SUP], Woon Joo Lee[SUP] 2 [/SUP], Tetsunari Maeda[SUP] 2 [/SUP], Takashi Kawashima[SUP] 2 [/SUP], Shinro Matsuura[SUP] 2 [/SUP], Ken-Ichi Doniwa[SUP] 2 [/SUP], Hitoshi Asamoto[SUP] 2 [/SUP], Masahiro Sugawara[SUP] 2 [/SUP]
Affiliations
Objective: To evaluate the effect of repeated vaccination on coronavirus disease (COVID-19) symptoms.
Methods: This retrospective, multicenter study was conducted across 15 Japanese medical institutions during the 11th wave of the COVID-19 epidemic in Japan. Patients diagnosed with COVID-19 via rapid antigen testing between July 1, 2024, and September 30, 2024, were enrolled. Data were collected using a questionnaire.
Results: The data of 408 patients were available for analysis; including 42.6 % were 40-59 years of age, 61.5 % female, and 35.8 % had a history of COVID-19. Seven doses of vaccine were associated with a significantly lower maximum body temperature and shorter fever duration (-0.79 °C, p < 0.001, and -1.50 days, p < 0.001, respectively). Past infection was associated with a significantly lower maximum body temperature and shorter fever duration (-0.35 °C, p < 0.001, and -0.75 days, p < 0.001, respectively). The symptoms in patients with past infection were significantly fewer at days 7, 14, and 30 than were those without past infection. For patients vaccinated seven times, symptoms were fewer after day 14. No significant difference was observed in the interval between onset and the last vaccination.
Conclusion: Repeated COVID-19 vaccination, particularly seven doses, was correlated with a lower maximum body temperature and shorter fever and symptom duration for patients during the 11th wave dominated by KP.3 variant. These findings highlight the importance of repeated vaccinations to mitigate the symptoms of COVID-19 with emerging variants.
Keywords: COVID-19; KP.3; Omicron; Symptom reduction; Vaccination.
. 2025 Aug 18;31(10):102798.
doi: 10.1016/j.jiac.2025.102798. Online ahead of print. The effectiveness of repeated vaccination for COVID-19 symptom resolution during the KP.3-dominant epidemic period in Japan: A retrospective multicenter study
Takuma Bando[SUP] 1 [/SUP], Hideyuki Ikematsu[SUP] 2 [/SUP], Naoki Kawai[SUP] 2 [/SUP], Keigo Shibao[SUP] 2 [/SUP], Masayuki Mizuguchi[SUP] 2 [/SUP], Tokunao Amemiya[SUP] 2 [/SUP], Satoshi Tsuchiya[SUP] 2 [/SUP], Yoshitaka Oribe[SUP] 2 [/SUP], Woon Joo Lee[SUP] 2 [/SUP], Tetsunari Maeda[SUP] 2 [/SUP], Takashi Kawashima[SUP] 2 [/SUP], Shinro Matsuura[SUP] 2 [/SUP], Ken-Ichi Doniwa[SUP] 2 [/SUP], Hitoshi Asamoto[SUP] 2 [/SUP], Masahiro Sugawara[SUP] 2 [/SUP]
Affiliations
- PMID: 40835168
- DOI: 10.1016/j.jiac.2025.102798
Objective: To evaluate the effect of repeated vaccination on coronavirus disease (COVID-19) symptoms.
Methods: This retrospective, multicenter study was conducted across 15 Japanese medical institutions during the 11th wave of the COVID-19 epidemic in Japan. Patients diagnosed with COVID-19 via rapid antigen testing between July 1, 2024, and September 30, 2024, were enrolled. Data were collected using a questionnaire.
Results: The data of 408 patients were available for analysis; including 42.6 % were 40-59 years of age, 61.5 % female, and 35.8 % had a history of COVID-19. Seven doses of vaccine were associated with a significantly lower maximum body temperature and shorter fever duration (-0.79 °C, p < 0.001, and -1.50 days, p < 0.001, respectively). Past infection was associated with a significantly lower maximum body temperature and shorter fever duration (-0.35 °C, p < 0.001, and -0.75 days, p < 0.001, respectively). The symptoms in patients with past infection were significantly fewer at days 7, 14, and 30 than were those without past infection. For patients vaccinated seven times, symptoms were fewer after day 14. No significant difference was observed in the interval between onset and the last vaccination.
Conclusion: Repeated COVID-19 vaccination, particularly seven doses, was correlated with a lower maximum body temperature and shorter fever and symptom duration for patients during the 11th wave dominated by KP.3 variant. These findings highlight the importance of repeated vaccinations to mitigate the symptoms of COVID-19 with emerging variants.
Keywords: COVID-19; KP.3; Omicron; Symptom reduction; Vaccination.