Guest edited by Daniel H. Paris, Claudia Daubenberger, Robert Bergquist, Hua-Qin Wang and Xiao-Nong Zhou
A thematic series in Infectious Diseases of Poverty.
As of 15 March 2021, more than 2.6 million people have died from COVID-19, caused by SARS-CoV-2. Progress of control has been capricious, but the number of cases are increasing again globally. There are still many uncertainties about COVID-19 and the threat of new variants. With continuing cases and threats from the COVID-19 pandemic, researchers worldwide are racing to develop vaccines against SARS-CoV-2 in an unprecedented effort.
Safe, effective COVID-19 vaccines are being rolled out. Existing data suggest that new vaccines (candidates) may be conducive to protect individuals and reduce the spread of pandemic. However, the development of vaccines in a very short time necessarily implies that is not yet possible to know their long-term efficacy and possible side effects. It is currently difficult to compare the various vaccines as there are no standardized assays for neutralization and challenge studies. The pros and cons of these vaccines (candidates) with the respective targets and strategies will need to be further analysed to better understand their safety, immunogenicity and protection rate. Assessment of the efficacy of a vaccine is complex for many diseases but particularly so in COVID-19 cases, where the fundamental understanding of the pathogen is evolving. Moreover, careful longitudinal studies will be needed to ascertain the duration of any protective immunity and potential disease enhancement for each vaccine candidate. Moreover, immunization programmes require further exploration.
Due to the short development time and the novelty of the technologies adopted, these vaccines will be deployed with several unresolved issues. The availability of these vaccines also in the poorest countries are imminent challenges facing us. Vaccines are reaching high income countries quickly, while the world’s poorest have hard access to them. In the long run more than one vaccine will be needed to ensure equitable global access, protection of diverse subjects and immunity against viral variants. The United Nations is supporting countries to mobilize the largest global immunization effort in history and promoting the equity in all people to end the pandemic. The study is needed on the equal accessibility of COVID-19 vaccines for the entire population of the world.
In order to meet challenges in assessing the efficacy of SARS-CoV-2 vaccines (candidates) and address the problems resulting from potential vaccine inequity, the series focuses on evidence on assessing the clinical efficacy of vaccines against SARS-CoV-2, strategies on how to optimize the vaccination, and studies on improving the equity of COVID-19 vaccination, etc.