Serological identification of past and recent SARS-CoV-2 infection through antibody screening in Luanda, Angola

Severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) emerged in China and spread to the world. 1 Pneumonia caused by SARS‐CoV‐2 was named coronavirus disease 2019 (COVID‐19) and is currently a public health concern. 2 , 3 From December 2019 to December 2020, more than 60.1 million cases of infection and 1.4 million deaths, have been reported worldwide. 4 Until December 2020, the Ministry of Health of Angola reported more than 15 000 cases and 345 deaths. 4 The timely diagnosis of SARS‐CoV‐2 infection is fundamental to ensure controlling of the COVID‐19 pandemic, the provision of treatment, and to avoid the worsening of the disease. 5 , 6 , 7 In practice, RT‐PCR is the only way to confirm the SARS‐CoV‐2. 8 There are individuals that despite being epidemiologically related and presenting pulmonary radiological findings compatible with SARS‐CoV‐2, remain RT‐PCR negative. 9 Factors such as the sample collecting and processing procedure may affect the result of the PCR assay. 10 Also, RT‐PCR does not distinguish virus with active replication from residual RNA, which could cause false results, especially in asymptomatic individuals. 10 Therefore, serologic tests offer an alternative to assess the degree of exposure amongst different population groups. 11 There are no published studies that assessed the rate of exposure and immune response to SARS‐CoV‐2 in Luanda, the capital city of Angola. Herein, we used serological assay to screen IgM and IgG antibodies against SARS‐CoV‐2 in individuals from Luanda, to support the Ministry of Health of Angola in the management of the COVID‐19.