What is in a vaccine and how does it work?
Social media has been rife with information from experts and wannabe experts on vaccines and what it does, clouding and muddling an already contentious issue.
But how do vaccines – particularly against CoViD – work?
Astrazeneca’s vaccine as well as Moderna’s and Pfizer’s basically have the same process in producing an immune response; the only difference is their delivery system.
Moderna’s and Pfizer’s vaccines use an mRNA encased with lipid nano particles.
This mRNA is sequenced from a SARS-COV-2 spike protein. The lipid nano particles help deliver the mRNA into the cells, then, within the cells, ribosomes translate it to form proteins that mimic the spike protein of SARS-COV-2.
This spike protein-like particles then attach to MHC 1 and MHC 2 receptors which in turn transmit signals to the immune system, effectively creating immune system cells such as B-cells and plasma cells that have been primed to produce antibodies that target and destroy particles carrying similar spike proteins like in the event of a real SARS-COV-2 infection.
The vaccine essentially teaches the immune system how to easily identify and kill the virus in the likelihood of its attack.
If this is still too technical to understand, basically the vaccine is filled with parts derived from SARS-COV-2 and teaches the body’s immune system about it in order to produce antibodies that will be able neutralize it when the real thing finally gets the chance to invade the body.
The only difference with Astrazeneca’s vaccine is that a DNA (instead of mRNA) sequenced from a SARS COV 2 spike protein is used and is encased with a non-infectious chimpanzee adenovirus vector (instead of the lipid nano particle).
Like Moderna’s and Pfizer’s lipid nano particle, the adenovirus vector helps the spike protein DNA into the cell.
It then goes into the nucleus and gets converted into mRNA – this mRNA goes out from the nucleus and follows the same process with the mRNA vaccines – ultimately producing immune cells primed for the real threat.
The thing about mRNA and DNA vaccines is that they are hard to transport into the cells as they are easily degradable by themselves. This is why they need vectors, basically transport boxes that deliver them safely, which is the lipid nano particle and the adenovirus vector, respectively.
While Astrazeneca’s, Moderna’s and Pfizer’s vaccines use novel technology, Sinovac uses “old tech” – the inactivated vaccine.
Basically, the virus is grown in a laboratory with conditions that either kill it or reduce its infectivity. Once it is injected into the cells, it activates an immune response similar to those mentioned above and subsequently primes the immune system for the virus. Rabies and flu vaccines have been using this inactivated vaccine technology for many years now.
Lastly, just to set it straight, there is a claim that mRNA vaccines can alter the genetic code and cause mutations and health problems. This is untrue and has been debunked by experts multiple times, as the claim itself seemingly does not know the basics of how a cell works, it’s unfortunate however that it’s being copy and pasted in various social media networks and has likely spread. Remember, mRNA are basically just instructions to produce proteins and don’t incorporate themselves into the genetic code.
Sinovac and Astrazeneca are the two vaccines so far that were successfully deployed in the Philippines.
So for this March update, let us collate essential information surrounding the two so far.
For the Sinovac vaccine, media focused and parroted the news about its 50% efficacy from the Butantan Institute’s Brazil trial, but without full context in which their conclusion said: “Brazil announced results on 13 January 2021 showing that it is 50.4% effective at preventing symptomatic infections, 78% effective in preventing mild cases needing treatment, and 100% effective in preventing severe cases.”
In the simplest terms having completed the 2 dose Sinovac vaccine, while there is still a small chance to get infected the vaccine absolutely protects one from developing severe symptoms and likely prevent death from COVID-19. Another simple example will be that the only thing COVID-19 can do to a person inoculated with Sinovac, may be a fever and / or sore throat, possibly a headache and that’s basically it. the body is primed enough from the vaccine that one may never need to be hospitalized, more so intubated, more so get severe symptoms.
Additionally, vaccine side effects which are easily treatable vs. a possibility of death in a healthcare system that lacks is never an argument.
For the Oxford-Astrazeneca vaccine, “One dosing regimen showed 90% efficacy in preventing contracting COVID-19 when a half-dose was followed by a full-dose after at least one month, based on mixed trials with no participants over 55 years old” this is based on a November 2020 press release by Astrazeneca, so to put that out of the way, here is what people are fearing from headlines about this vaccine this month (March 2021), which are news about Blood Clots.
The investigation from the European Medicine Agency (EMA) stated that there is no causal link between thromboembolic and other blood clot related events to the Astrazeneca vaccine.
Let’s call it simply blood clots to make the statements simpler. The EMA said that the amount of blood clots that happened are but the normal, usual occurrence of blood clots in the general population, and have not increased due to vaccination.
Europe at this time had more than five million people already vaccinated; among these are a few blood clot events possibly due to an underlying cardiovascular disease already on its way to pop out regardless of the vaccine – and vaxxed or unvaxxed, the blood clots may have been already on its way to occur in these individuals and that does not mean the vaccine caused or activated it.
It’s like in the case of Sinovac’s Phase III trials in the Brazil last November 2020, where one (1) volunteer died of suicide. The medical community strictly adheres to the knowledge that suicide is a known effect of psychiatric illnesses, likely undiagnosed on that volunteer and is not caused by the vaccine, still it was investigated and subsequently Instituto Butantan biologic research center concluded no link for the suicide to the vaccine trial.
Despite these proofs, Sinovac was halted temporarily. Astrazeneca followed suit after these events. Why? Because it is routine in science to investigate, showing that these surveillance systems and protocols for safety are working and are in place, assuring us about the status of these vaccines.
Likewise the latest evidences collated by the experts from Butantan research center in Brazil show no correlation to suicide and the experts from the EMA show no correlation to blood clots. Vaccination generally not dramatic, but it’s a sure way to prevent one from dying of the diseases they are used for.
The Philippines’ vaccination officially began on 1 March 2021 shortly after the arrival of the first batch of vaccines from Sinovac. According to the Department of Health (DOH), as of 25 March 2021, about 608, 962 individuals have been vaccinated across the country.
The government also plans to start a mass vaccination program by May 2021.
The Food and Drug Administration (FDA) has issued emergency use authorizations (EUA) to the Pfizer–BioNTech, Oxford–AstraZeneca, Sinovac COVID-19 vaccines, and Gamaleya-Sputnik V.
There are eight other vaccines on order for the program, at varying stages of development.
