en Infectious Diseases Infectious Diseases Original Article Original Article <span style="font-size:14px;"><span style="font-family:Times New Roman;"><span style="line-height:14pt"><b><i><span style="color:blue">Background</span></i></b><i><span style="color:blue">:</span></i> Although vaccination is the most effective and specific approach for prevention of infectious diseases, but in a small percentage of vaccinated person&rsquo;s breakthrough infections can occur. This study aimed to determine the effectiveness of different common <i>coronavirus</i> vaccines in this area.</span><br> <span style="line-height:14pt"><b><i><span style="color:blue">Methods:</span></i></b> 109 COVID-19 vaccinated patients were enrolled, with different types of vaccines (Sinopharm, AstraZeneca, Sputnic, Bharath, CovIran Barkat and Pasto-CoV) and time of administration in 2021 in Babol, Iran. Patients after 14 days of administration of the final dose of corona vaccines with positive COVID-19 RT-PCR test entered to study. Patients&rsquo; data such as RT-PCR, type of vaccine, age, sex and outcome were collected using electronic medical records.</span><br> <span style="line-height:14pt"><b><i><span style="color:blue">Results:</span></i></b> 47 patients were not fully vaccinated, 62 had two vaccine doses and 51 were fully vaccinated and considered to a breakthrough infection. Although, most of the patients with&nbsp; <i>SARS-CoV-2</i> infection were either mild (n=18 [16.56%]), or moderate (n=86 [78.9%]), 5 (4.6%) patients had severe or critical illness, of whom 3 admitted in intensive care unit, 3 intubated, and 4 died. The average age of the participants with COVID-19 infections was 61.23 &plusmn; 19.91 years. </span><br> <span style="line-height:14pt"><b><i><span style="color:blue">Conclusion</span></i></b><i><span style="color:blue">:</span></i> Based on our results, the <i>COVID-19</i> breakthrough occurring with two doses of current vaccines were mild and moderate. </span></span></span><br> &nbsp; SARS-CoV-2, COVID-19, Vaccine, breakthrough. 644 650 http://caspjim.com/browse.php?a_code=A-10-137-4&slc_lang=en&sid=1 Mana Baziboroun manabaziboron@gmail.com 100319475328460049955 100319475328460049955 No Infectious Diseases and Tropical Medicine Research Center, Health Research Institute, Babol University of Medical Sciences, Babol, Iran. Sayareh Hosseinzadeh hosseinzadehsayareh@gmail.com 100319475328460049956 100319475328460049956 No Part of Infectious Control, Ayatollah Rouhani Hospital, Babol University of Medical Sciences, Babol, Iran. Hemmat Gholinia h_gholinia@yahoo.com 100319475328460049957 100319475328460049957 No Social Determinants of Health Research Center, Health Research Institute, Babol University of Medical Sciences, Babol, Iran. Farzin Sadeghi sadeghi.farzin@yahoo.com 100319475328460049958 100319475328460049958 No Cellular and Molecular Biology Research Center, Health Research Institute, Babol University of Medical Sciences, Babol, Iran. Yousef Yahyapour uyahyapoor@yahoo.com 100319475328460049959 100319475328460049959 Yes Infectious Diseases and Tropical Medicine Research Center, Health Research Institute, Babol University of Medical Sciences, Babol, Iran.