To limit behaviors that drive the spread of covid-19, the pandemic has nearly paralyzed our lives, and there is no sign yet as to when it will slow down without these measures. The only hope remains in Covid-19 vaccines, which presently are available in many forms, from various producers, and with different characteristics. But why do we have so many vaccine types, and how do they differ? Is one better than the other and which one should you take?
Why are there so many Covid-19 vaccines?
Usually, the discovery of a vaccine involves many vaccine candidates’ going through trials before some of them are found to be both safe and effective. According to WHO, for vaccines studied in the lab and laboratory animals, about 7 out of every 100 will be considered safe and effective enough to continue into the clinical trials with humans. Of the vaccines that do make it to testing among humans, just one in five is successful. Therefore, starting with a high number of vaccine candidates increases the chance of having at least a few, which will be safe and effective in preventing the targeted disease. For Covid-19, around 200 vaccine candidates were registered by WHO, and about six are now widely accepted for use.
How do the current vaccines differ?
There are three main approaches to designing a vaccine. Their differences lie in whether they use:
The whole virus or bacterium:
It can be a disease-carrying virus or bacterium inactivated or killed using chemicals, heat, or radiation, such as how the flu and polio vaccines are made.
It can be a living but weakened version of the virus what is known as a live-attenuated vaccine. The measles, mumps, and rubella (MMR) vaccine is made this way. Note that these types of vaccines are not suitable for people with compromised immunity.
It can also be viral sub-parts known as proteins delivered into our body using another virus called a “safe virus.” That vector virus triggers the immune response without causing disease. The Ebola virus vaccine is an example of a viral vector vaccine.
The parts of the germ that triggers the immune system:
There are very specific parts (the subunits) of a virus or bacterium that the immune system needs to recognize. Those subunits may be proteins or sugars. Most of the vaccines on the childhood vaccination schedule, protecting against whooping cough, tetanus, diphtheria, and meningococcal meningitis, are subunit vaccines.
The genetic material
The genetic material from a virus provides the instructions for making specific proteins that our immune system recognizes and responds to. This is a new method and is also referred to as the genetic approach that produces nucleic acid vaccines. Unlike other strategies discussed above, this technique uses a section of genetic material from DNA or RNA that provides the instructions for specific proteins that our immune system recognizes and responds to. In cells, the DNA is copied into a messenger RNA, which is then used as the blueprint to make specific proteins.
The genetic approach is a new way of developing vaccines as before the COVID-19 pandemic; none had yet been approved for use in humans, even though some DNA vaccines for some cancers were undergoing human trials. The pandemic has heavily accelerated the progress of research in this area, and as of now, some mRNA vaccines for COVID-19 have gotten emergency use authorization despite being in trials.
All covid-19 vaccines pass through rigorous checks for receiving approval for human trials. All Covid-19 vaccines were granted emergency use authorization, which means that they can be used even though they are still under research process. For a quick comparison, the table below describes some differences between them.
So which one should you choose?
That’s for each individual to make their informed decision about. The results and efficiency from the trials can change in the future per the more data we get from ongoing research, but at least now you know the basics and the differences between the available vaccines.
Bear in mind that there might not even be an opportunity to actually choose which vaccine you should get considering the immense demand for Covid-19 vaccines all over the world. You might need to choose the ones that are available in your proximity.
Either Way and most importantly - all the available vaccines have proven, with varying results, to be effective in protecting you against severe COVID-19 infection.
For more information about vaccines in general or the Covid-19 vaccines, reach out to our doctors available 24/7 in the BYON8 app.
Until next time,
Be safe and well!