- Taskin Meher
“Pssst…. Is the Covid vaccine really safe?” “My question exactly, it did come out earlier than normal vaccines…” “Very sus.”
So yeah, the lines above are exactly most people’s concern nowadays. This is because a typical vaccine takes an average of 10 to 15 years before it is fully legalized for usage. But what is happening? Covid vaccine came in less than a year? So is it safe??
Yes, the vaccine is safe. That is because, researches were conducted previously on related viruses and technology has advanced a lot more than before. Coronavirus has a very old history. Coronaviruses (CoV) are a large family of viruses that cause illness ranging from common cold to severe diseases. A noble Coronavirus (nCoV) is a new strain that hasn’t been identified in humans before, hence scientists named it “COVID-19 Virus”.
Before a vaccine is legalized, it has to be successfully developed, undergo pre-clinical stage, 3 clinical trials, registered and then licensed. Overall, it’s a very lengthy process. Before we go on to Covid vaccines, you should know that there are different types of vaccines;
mRNA VACCINE: uses genetic material called ‘messenger RNA’ that instructs cells to make a piece of coronavirus spike protein.
VECTOR VACCINES: use another virus to carry in genetic instructions to make the spike protein
PROTEIN SUBUNIT VACCINE: Genetically engineered viruses are used to infect moths, whose cells are then used to produce the pieces of coronavirus spike proteins. These are then harvested and made into vaccines.
WHOLE, KILLED VACCINES: Takes longer to make as batches of coronavirus must first be grown and then killed using a chemical or heat, and then made into a vaccine that can be injected. A lot of possible Covid-19 vaccines are still undergoing development processes, but the most famous ones so far are as follows; Pfizer, Moderna, AstraZeneca. Janssen, Sputnik, Novavax, Sanofi, Sinovac.
PFIZER (mRNA)
In the case of this vaccine, the mRNA instructs cells in the body to make the particular piece of the virus’s spike protein. Then the immune system sees it, recognizes it as foreign and is prepared to attack when actual infection occurs (memory cells). mRNA is very fragile, so it’s encased in lipid nanoparticles--- a coacting of buttery substance that can melt at room temperature. Pfizer’s vaccine must be kept at ultracold temperatures of about -100 degrees Fareinheit. It is to be given doses of 2 shots, each about 21 days apart.
Efficiency rate: 95%
MODERNA (mRNA)
This vaccine is said to be 94.1% efficient. And like Pfizer, it codes for cells to make a piece of the spike protein. The major difference between Pfizer and Moderna is that the later one can still keep functioning at a higher temperature. It can be shipped at -20 degree Celsius, and stored at 2 or 8 degree Celsius. Dose: 2 shots, 1 month apart
ASTRAZENECA (Vector)
AstraZeneca uses a common cold virus called an adenovirus* to carry the spike protein from the coronavirus into cells. With an efficiency rate of about 70%, it also aims to make people’s bodies in essence produce their own vaccines by churning out little copies of spike protein, but the delivery method is different. This adenovirus infects chimpanzees but doesn’t make people sick. It was modified so that it doesn’t replicate itself—then genetically engineered to inject cells with the DNA encoding for the full coronavirus spike protein. It’s a cheaper way to make vaccines, but slower than using RNA. This vaccine can be kept stable for 6 months in normal refrigerator temperature. Dose: 2
JANSSEN (Vector)
Like AstraZeneca, it uses an adenovirus but this one does infect humans. It is a genetically engineered version of adenovirus26, which can cause common cold but the gene tinkering has disabled it. It also delivers the genetic instructions to make spike protein. This vaccine had been tested in the market before, the adenovirus26 was used to make Ebola vaccine. Dose: used to be a one-shot vaccine, but now requires two shots.
SPUTNIK (Vector)
Russia’s Sputnik V coronavirus vaccine is an adenoviral vaccine as well. It uses two common cold viruses called adenovirus5 and adenovirus26 to carry the genetic material for the spike protein into the body. Like other vector vaccines, this one is cheaper than RNA vaccines as well. Doses: 2
NOVAVAX (Protein Sub-Unit)
Novavax uses virus-like nanoparticles as a base and covers them with genetically engineered pieces of coronavirus spike protein. It uses an insect virus called a Baculovirus to get the coronavirus spike protein into moth cells, which then produce the protein. This is harvested and mixed with an adjuvant.
SINOVAC (Whole, Killed)
Chinese company SInovac’s CoronaVac uses an inactivated virus—one of the oldest methods for vaccinating people. Whole batches of coronaviruses are grown, ‘killed’ and then made into vaccines. These are then injected into people in small doses.
There are so many other vaccines undergoing research even if it takes time. Still it is one of the greatest achievements of humanity as no other vaccine has been created in this much short amount of time.
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