Kandhasamy Vanathy, Priyadarshini Ramya, Bhosale Namrata Krishna, Ramachandran Pillai Raji, Ramalingam Malarvizhi, Balakrishna Pillai Agiesh Kumar, Govindasamy Ezhumalai, Maducolil Easow Joshy
Department of Microbiology, Mahatma Gandhi Medical College & Research Institute (MGMCRI), Sri Balaji Vidyapeeth (Deemed to be University), Pondicherry, Puducherry, India.
Department of Microbiology, Vinayaka Mission's Medical College and Hospital, Vinayaka Mission's Research Foundation (Deemed to be University), Karaikal, Puducherry, India.
Iran J Microbiol. 2025 Apr;17(2):194-203. doi: 10.18502/ijm.v17i2.18380.
The COVID-19 pandemic was mitigated by the rapid development and deployment of vaccines. While vaccines reduce infection severity, breakthrough infections (BTIs) still occur. The CDC defines BTI as a positive SARS-CoV-2 test ≥14 days post-vaccination. This study investigates the occurrence of COVID-19 BTIs at a tertiary care hospital in Puducherry, South India.
This retrospective study analysed hospital tested qRT-PCR data of individuals from the ICMR portal (March 2021-March 2022). Demographic and vaccination details were extracted.
Among 8001 tested individuals, 1452 were vaccinated. The BTI rate decreased from 16.6% to 1.2% after the first dose and from 58% to 40% after the second one. Odds ratio indicated a 74% reduction in infection risk for vaccinated individuals compared to unvaccinated. Males had higher infection rates than females, regardless of vaccination status.
Our study demonstrates a higher BTI rate after one vaccine dose compared to two doses. The BTI rate also increased four months post-vaccination, even with two doses, potentially due to waning immunity and the emergence of new variants. Therefore, continued adherence to preventive measures in conjunction with vaccination is crucial for minimizing COVID-19 transmission.
新冠病毒疫苗的迅速研发和推广缓解了新冠疫情。虽然疫苗可降低感染的严重程度，但仍会出现突破性感染（BTI）。美国疾病控制与预防中心（CDC）将BTI定义为接种疫苗14天及以后新冠病毒检测呈阳性。本研究调查了印度南部本地治里一家三级护理医院中新冠病毒突破性感染的发生情况。
这项回顾性研究分析了来自印度医学研究理事会（ICMR）门户网站（2021年3月至2022年3月）的个体的医院检测定量逆转录聚合酶链反应（qRT-PCR）数据。提取了人口统计学和疫苗接种详细信息。
在8001名接受检测的个体中，1452人接种了疫苗。接种第一剂疫苗后，突破性感染率从16.6%降至1.2%，接种第二剂后从58%降至40%。优势比表明，与未接种疫苗的个体相比，接种疫苗的个体感染风险降低了74%。无论接种状况如何，男性的感染率均高于女性。
我们的研究表明，接种一剂疫苗后的突破性感染率高于接种两剂。即使接种了两剂疫苗，接种疫苗四个月后的突破性感染率也有所上升，这可能是由于免疫力下降和新变种的出现。因此，持续坚持预防措施并结合接种疫苗对于最大限度减少新冠病毒传播至关重要。
