  Over the past 150 years, vaccines have revolutionized the relationship
between people and disease. During the COVID-19 pandemic, technologies such as
mRNA vaccines have received attention due to their novelty and successes.
However, more traditional vaccine development platforms have also yielded
important tools in the worldwide fight against the SARS-CoV-2 virus. A variety
of approaches have been used to develop COVID-19 vaccines that are now
authorized for use in countries around the world. In this review, we highlight
strategies that focus on the viral capsid and outwards, rather than on the
nucleic acids inside. These approaches fall into two broad categories:
whole-virus vaccines and subunit vaccines. Whole-virus vaccines use the virus
itself, either in an inactivated or attenuated state. Subunit vaccines contain
instead an isolated, immunogenic component of the virus. Here, we highlight
vaccine candidates that apply these approaches against SARS-CoV-2 in different
ways. In a companion manuscript, we review the more recent and novel
development of nucleic-acid based vaccine technologies. We further consider the
role that these COVID-19 vaccine development programs have played in
prophylaxis at the global scale. Well-established vaccine technologies have
proved especially important to making vaccines accessible in low- and
middle-income countries. Vaccine development programs that use established
platforms have been undertaken in a much wider range of countries than those
using nucleic-acid-based technologies, which have been led by wealthy Western
countries. Therefore, these vaccine platforms, though less novel from a
biotechnological standpoint, have proven to be extremely important to the
management of SARS-CoV-2.
