Plausible Efficacy of COVID-19 Vaccination Against Covid-like Symptoms in Nigeria: A Cross-sectional Study.

Background: Vaccination strengthens the immune system by using the body’s intrinsic defense mechanisms to enhance resistance to notable or specific disease agents. A cross-sectional community-based study comparing the occurrence of Covid-like symptoms among individuals earlier vaccinated or unvaccinated against Covid-19 using all the four different vaccine types administered in Nigeria. Given that Sub-Sahara Africans were not included in the vaccine clinical trials before Emergency Use Authorization, this study could provide indirect evidence on the effectiveness or otherwise of the vaccines among Nigerians. Methods: A cross-sectional community-based study of prevalence of covid like symptoms reported in subjects who had received any of the Covid-19 vaccine types deployed in Nigeria compared with subjects who had not received any of the vaccines in the six geo political zones of the country. A multi-stage sampling technique was used to select 24 Local government Areas from all six (6) geopolitical zones of the country. Results: Lesser proportion of subjects who had received any of the COVID-19 vaccines reported experiencing symptoms such as headaches, muscle, joint aches, fatigue, fever, sore throat, cough, and chills in the preceding 3 months to the survey as compared to subjects who had not received any of the vaccines. These observed differences were statistically significant, (p<0.05). Conclusion: The COVID-19 vaccines would appear protective against the symptoms of interest based on these findings. The reduction in the proportions reporting symptoms for the different types of vaccine are invariably similar therefore vaccine recipients can be encouraged to receive any brand to curb the pandemic.