ABSTRACT
BACKGROUND: Reports on the evaluation of immune responses to different COVID-19 vaccines are limited. Similarly, effects of age and gender have not been well explored as variables that could impact on the vaccine-induced antibody response. Therefore, seroprevalence of anti-SARS-CoV-2 specific antibodies in vaccinated and vaccine naïve adult Nigerians was determined in this study. METHODOLOGY: A total of 141 adults were enrolled into this study. Presence or absence of SARS-CoV-2 infection was confirmed by real-time reverse-transcriptase polymerase-chain reaction (RT-PCR) assay on nasopharyngeal and oropharyngeal swab specimens. Anti-SARS-CoV-2 Specific IgG and IgM antibodies were qualitatively detected using a Rapid Diagnostic Test kit. RESULTS: Pre-vaccination, 77% of the study participants had never had PCR-confirmed COVID-19 test yet 66.7% of them were seropositive for SARS-CoV-2 antibodies. Of 111 COVID-19 vaccinated participants, 69.2% and 73.8% of them had SARS-CoV-2 specific IgG post-first and second doses of COVID-19 vaccine respectively. However, 23.1% and 21.4% of the participants who have had first and second doses respectively had no detectable anti-SARS-CoV-2 antibodies. The proportion of participants with SARS-CoV-2 specific IgG was insignificantly higher in those between the ages of 18-40 years and 41-59 years compared with individuals aged ≥60 years. No significant association was observed between gender and seropositivity for SARS-CoV-2 antibodies. CONCLUSION: There is high SARS-CoV-2 antibody seroprevalence among Nigerian adults who never had PCR-confirmed COVID-19. Also, there is the need for anti-SARS-CoV-2 antibodies screening post vaccination as this could be essential in achieving herd immunity. Age and gender do not seem to have significant association with seropositivity.
Subject(s)
COVID-19 , Vaccines , Humans , Adult , Adolescent , Young Adult , COVID-19 Vaccines , Seroepidemiologic Studies , SARS-CoV-2 , Antibodies, Viral , Immunoglobulin G , Real-Time Polymerase Chain ReactionABSTRACT
Severe Acute Respiratory human Coronavirus 2 (SARS-hCOV 2) infection which began in December 2019 has rapidly disseminated worldwide due to non-availability of anti-viral treatment or vaccine, no knowledge of virus-human interaction, lack of prognostic factors for stages of illness and ability of hCoV 2 to rapidly mutate and infect multiple cell types. Host inflammation and evasion of host immune responses by viruses are believed to play major roles in disease severity of human Corona viruses (hCoVs), thus uses of anti-inflammatory and immune-boosting agents apart from complete multi-disciplinary approach are suggested to combat the ranvaging SAR-hCOV 2 infection. This paper related the structural proteins and life cycle of CoV with host immune responses to CoV. This is to bring out gaps in knowledge for possible future researches.