tetano
Editor, Senior Moderator
Int J Infect Dis
. 2024 Jul 31:107179.
doi: 10.1016/j.ijid.2024.107179. Online ahead of print. Relative vaccine effectiveness of ChAdOx1/AZD1222 vaccines as booster dose via intradermal injection with a one-fifth dose compared with the intramuscular injection in the prevention of SAR-CoV-2 infections in Phuket - A Retrospective Cohort Study
Withita Jangiam[SUP] 1 [/SUP], Kusuma Swangpun[SUP] 2 [/SUP], Sopon Iamsirithaworn[SUP] 3 [/SUP], Suchanuch Piriyasatit[SUP] 4 [/SUP], Dhup Bhukdee[SUP] 5 [/SUP]
Affiliations
Objectives: This study assessed the real-world relative vaccine effectiveness of the ChAdOx1/AZD1222 vaccine given intradermally at one-fifth dose compared to the standard intramuscular injection, following the completion of two doses of CoronaVac, due to limited vaccine availability in Thailand during the Coronavirus disease 2019 (COVID-19) pandemic.
Method: This retrospective cohort study used 138,264 records from Vachira Phuket Hospital, Phuket, Thailand. The records were divided into two groups: 49,387 recipients received one-fifth doses via intradermal injections, and 88,877 recipients received standard-dose intramuscular injections from September 14 to October 3, 2021, with follow-up until December 31, 2021. Relative vaccine effectiveness for the cohorts was estimated using Cox regression, adjusting for demographic and clinical risk factors.
Results: The adjusted hazard ratio between the intradermal and intramuscular groups was 0.88 (95% Confidence Interval 0.76-1.02, p = 0.09), indicating a non-significant protective factor for the intradermal group. Further stratified analysis revealed no significant difference between the two groups. The 21 and 28-day post-vaccination periods minimized the possibility of confounding due to differences in the cohorts' timeframes.
Conclusion: A booster dose of ChAdOx1/AZD1222 given intradermally at one-fifth dose did not show a significant difference compared to the standard intramuscular injection.
Keywords: COVID-19; COVID-19 vaccines; intradermal injection; intramuscular injection; telative vaccine effectiveness.
. 2024 Jul 31:107179.
doi: 10.1016/j.ijid.2024.107179. Online ahead of print. Relative vaccine effectiveness of ChAdOx1/AZD1222 vaccines as booster dose via intradermal injection with a one-fifth dose compared with the intramuscular injection in the prevention of SAR-CoV-2 infections in Phuket - A Retrospective Cohort Study
Withita Jangiam[SUP] 1 [/SUP], Kusuma Swangpun[SUP] 2 [/SUP], Sopon Iamsirithaworn[SUP] 3 [/SUP], Suchanuch Piriyasatit[SUP] 4 [/SUP], Dhup Bhukdee[SUP] 5 [/SUP]
Affiliations
- PMID: 39094764
- DOI: 10.1016/j.ijid.2024.107179
Objectives: This study assessed the real-world relative vaccine effectiveness of the ChAdOx1/AZD1222 vaccine given intradermally at one-fifth dose compared to the standard intramuscular injection, following the completion of two doses of CoronaVac, due to limited vaccine availability in Thailand during the Coronavirus disease 2019 (COVID-19) pandemic.
Method: This retrospective cohort study used 138,264 records from Vachira Phuket Hospital, Phuket, Thailand. The records were divided into two groups: 49,387 recipients received one-fifth doses via intradermal injections, and 88,877 recipients received standard-dose intramuscular injections from September 14 to October 3, 2021, with follow-up until December 31, 2021. Relative vaccine effectiveness for the cohorts was estimated using Cox regression, adjusting for demographic and clinical risk factors.
Results: The adjusted hazard ratio between the intradermal and intramuscular groups was 0.88 (95% Confidence Interval 0.76-1.02, p = 0.09), indicating a non-significant protective factor for the intradermal group. Further stratified analysis revealed no significant difference between the two groups. The 21 and 28-day post-vaccination periods minimized the possibility of confounding due to differences in the cohorts' timeframes.
Conclusion: A booster dose of ChAdOx1/AZD1222 given intradermally at one-fifth dose did not show a significant difference compared to the standard intramuscular injection.
Keywords: COVID-19; COVID-19 vaccines; intradermal injection; intramuscular injection; telative vaccine effectiveness.