Douglas Henrique Pereira Damasceno1, Arthur Aguiar Amaral1, Cecília Andrade Silva1, Ana Cristina Simões E Silva1.
Abstract
BACKGROUND: The COVID-19 pandemic demanded a global effort towards quickly developing safe and effective vaccines against SARS-CoV-2.
OBJECTIVE: This review aimed to discuss the main vaccines available, their mechanisms of action, results of clinical trials, and epidemiological behavior. The implications of viral variants were also debated.
METHODS: A non-systematic literature review was performed between February and March 2021 by searching the Pubmed, Scopus, and SciELO databases, using different combinations of the following terms: "vaccines", "clinical trials" , "SARS-CoV-2", "Coronavirus", "COVID-19", "mechanisms of action". Data regarding clinical trials of SARS-CoV-2 vaccines and epidemiological information were also searched.
RESULTS: The mechanisms of action included vector-virus, mRNA and inactivated virus vaccines. The vaccines showed positive results in phases 2/3 clinical trials. The efficacy of the mRNA 1273 and of mRNA BNT 162b2 vaccines were 94.1% and 95%, respectively. The effectiveness of the ChAdOx1 nCoV-19 vaccine varied according to the scheme, with an overall value of 70.4%. The Gam-COVID-Vac vaccine had an efficacy of 91.6%. Regarding the Ad26.COV2.S vaccine, 99% or more of seroconversion was observed in all subgroups 29 days after vaccination. The CoronaVac vaccine induced an immune response in 92% of the volunteers receiving 3ug and in 98% with 6ug, in comparison to 3% in the placebo group.
CONCLUSION: Global efforts have resulted in vaccines being available in record time, with good safety and immunogenicity profile. However, only long-term studies can provide more information on the duration of immunity and the need for additional doses. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.
BACKGROUND: The COVID-19 pandemic demanded a global effort towards quickly developing safe and effective vaccines against SARS-CoV-2.
OBJECTIVE: This review aimed to discuss the main vaccines available, their mechanisms of action, results of clinical trials, and epidemiological behavior. The implications of viral variants were also debated.
METHODS: A non-systematic literature review was performed between February and March 2021 by searching the Pubmed, Scopus, and SciELO databases, using different combinations of the following terms: "vaccines", "clinical trials" , "SARS-CoV-2", "Coronavirus", "COVID-19", "mechanisms of action". Data regarding clinical trials of SARS-CoV-2 vaccines and epidemiological information were also searched.
RESULTS: The mechanisms of action included vector-virus, mRNA and inactivated virus vaccines. The vaccines showed positive results in phases 2/3 clinical trials. The efficacy of the mRNA 1273 and of mRNA BNT 162b2 vaccines were 94.1% and 95%, respectively. The effectiveness of the ChAdOx1 nCoV-19 vaccine varied according to the scheme, with an overall value of 70.4%. The Gam-COVID-Vac vaccine had an efficacy of 91.6%. Regarding the Ad26.COV2.S vaccine, 99% or more of seroconversion was observed in all subgroups 29 days after vaccination. The CoronaVac vaccine induced an immune response in 92% of the volunteers receiving 3ug and in 98% with 6ug, in comparison to 3% in the placebo group.
CONCLUSION: Global efforts have resulted in vaccines being available in record time, with good safety and immunogenicity profile. However, only long-term studies can provide more information on the duration of immunity and the need for additional doses. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.
Entities:
Keywords:
COVID-19; SARS-CoV-2; coronavirus; immune response; impacts of vaccination; new variants; vaccinal coverage; vaccines
Mesh：
Substances：
Year: 2022
PMID： 34473613 DOI： 10.2174/0929867328666210902094254
Source DB: PubMed Journal: Curr Med Chem ISSN： 0929-8673 Impact factor: 4.530