COVID-19 vaccines: Current evidence and considerations

The coronavirus disease 2019 (COVID-19) pandemic is a global crisis, with devastating health, business and social impacts. Vaccination is a safe, simple, and effective way of protecting a person against COVID-19. By the end of August 2021, only 24.6% of the world population has received two doses of a COVID-19 vaccine. Since the emergence of COVID-19, several COVID-19 vaccines have been developed and approved for emergency use. Current vaccines have shown efficacy with low risk of adverse effects. However, COVID-19 vaccines have been related to a relatively small number of cases of heart inflammation, anaphylaxis (allergic reactions), and blood clots formation. On the other hand, COVID-19 vaccination is not recommended for children less than 12 years of age. Furthermore, It has been proposed that some new variants (e.g., Lambda and Delta) are proficient in escaping from the antiviral immunity elicited by vaccination. Herein we present current considerations regarding the COVID-19 vaccines including: efficacy against new variants, challenges in distribution, disparities in availability, dosage gender and race difference, COVID-19 vaccine transport and storage, limitations in children and pregnant women. Long-time monitoring is essential in order to find vaccine efficacy and to rule out related side effects.