A comprehensive review on COVID-19 vaccines: development, effectiveness, adverse effects, distribution and challenges

The present SARS-CoV-2 induced COVID-19 pandemic is responsible for millions of deaths, illnesses, and economic loss worldwide. There are 21 COVID-19 vaccines from different platforms approved worldwide for emergency use until 13 August 2021. Later, BNT162b2 obtained full approval from the FDA. The efficacy of the leading vaccines such as BNT162b2, mRNA-1273, Gam-Covid-Vac, Ad26.COV2.S, ChAdOx1 nCoV-19, and BBIBP-CorV, against SARS-CoV-2 documented as 95%, 94.1%, 91.6%, 67%, 70.4%, and 78.1%, respectively. Moreover, against the Delta variant of SARS-CoV-2, BNT162b2, ChAdOx1 nCoV-19, and BBV152 showed 88%, 70%, and 65.2% efficacy, respectively. Apart from the common adverse effects such as fever, fatigue, headache, and pain in the injection site, Bell's palsy with BNT162b2, myocarditis and pericarditis with mRNA-1273, and thrombosis with ChAdOx1 nCoV-19 have been reported though seemed not alarming. Furthermore, global production and distribution of vaccines should be ensured in an equal and justifiable way that the immunity and protection against the virus would be optimum and persistent.