COVID-19 vaccines work by introducing the immune system to an inactivated form of the SARS-CoV-2 coronavirus or a part of it. This does not cause COVID-19 but equips the body to fight against future infection with the virus.
All data and statistics are based on publicly available data at the time of publication. Some information may be out of date.
All vaccines work by training the immune system to respond to future infection. Vaccines are overwhelmingly safe for the majority of people who receive them, and they do not cause disease.
There are 12 vaccines against COVID-19 that have authorization for use in various locations around the world.
Vaccine developers worked under unprecedented conditions to develop vaccines against COVID-19 after the emergence of the SARS-CoV-2 virus in late 2019. It took less than a year for the first COVID-19 vaccines to gain authorization for use.
While this is significantly faster than for all other vaccines, developers leveraged existing vaccine technology and a concerted global effort — working alongside health authorities such as the Food and Drug Administration (FDA) — to work at this pace.
In this Special Feature, we take a look at how different COVID-19 vaccines work and what scientists mean when they talk about side effects and vaccine efficacy.
Specifically, we cover:
- mRNA vaccines
- viral vector vaccines
- subunit vaccines
- inactivated vaccines
- vaccine side effects
- vaccine efficacy
Although all of the COVID-19 vaccines in use around the world aim to achieve the same goal — namely, protection from COVID-19 — they employ different vaccine technologies.
Some vaccines are based on the whole SARS-CoV-2 virus, others use only parts of it, and some do not use any material derived directly from the virus.
The sections below provide an overview of the different types of COVID-19 vaccines that have authorization for use in at least one country.
mRNA vaccines
The COVID-19 mRNA vaccines that BioNTech-Pfizer and Moderna developed are the first mRNA vaccines authorized for use in humans outside of clinical trials. However, the technology is not new.
Scientists have been working on mRNA vaccine candidates for infectious diseases and cancer for a number of years.
mRNA vaccines do not contain any part of the SARS-CoV-2 virus. Instead, they carry a chemically synthesized piece of messenger (m)RNA that contains the information necessary for our own cells to make the SARS-CoV-2 spike protein.
Our cells make this protein and present it to our immune system, which responds by creating antibodies and developing longer lasting immunity in the form of T cell and B cell responses.
It is not possible to develop COVID-19 from an mRNA vaccine because it does not carry the instructions necessary to make the entire coronavirus.
Source: Medical News Today
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