The coronavirus disease 2019 (COVID-19) was declared a pandemic by the World Health Organization (WHO) on the 11^th of March 2020. In Romania, there have been 983,217 confirmed cases and 24,386 deaths. We aim to show our experience at the Fundeni Clinical Institute in the diagnosis of Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) infection in both patients and health care personnel. Swab samples were collected for extraction of the SARS-CoV-2 RNA from 29380 patients and health care personnel. We have combined three real-time reverse transcription-polymerase chain reaction (RT-PCR) assays for the qualitative detection of SARS-CoV-2. Also, the presence of IgG against SARS-CoV-2 nucleoprotein was analyzed in 1068 patients and clinical staff using the chemiluminescence method. Other 50 people were screened post-vaccination for the presence of SARS-CoV-2 antibodies against the spike (S) protein, using the chemiluminescence method as well. The majority of confirmed cases were in adults, 71.3% of cases being registered in people aged 30-69 years. Most patients diagnosed with SARS-CoV-2 infection (83%) were admitted to the gastroenterology, hematology, and surgery wards. Our study showed that one-third of people developed antibodies against the nucleocapsid of SARS-CoV-2. SARS-CoV-2 IgG seroprevalence does not vary by gender or age. Also, we noticed the presence of antibodies against the SARS-CoV-2 spike protein in all 50 people post-vaccination that were tested two weeks after the second dose. Due to the increasing number of infected patients with SARS-CoV-2, the new coronavirus pandemic involves a sustained testing effort for an accurate virological diagnosis in both direct and indirect diagnosis.