A coronavirus, unlike some viruses that turn us into lifelong carriers (like herpes or HIV), can actually be eliminated from our body.
Zania Stamataki, a viral immunology researcher and lecturer at the University of Birmingham, explains that we have two different types of defense mechanisms that are responsible for responding quickly and accurately to a viral invasion. The defenses can be carried out by skin, saliva, tears, mucus, cilia (tiny hair), stomach acid, urine flow or “friendly” bacteria as well as an army of white blood cells. This rapid defense can be recognized when we suffer from an illness (fever, pain, redness).
The second type of defense explains accuracy, which develops more slowly. it includes B cells and T cells (called “immune cells”). T cells act like powerful serial killers, kissing virus-kidnapped cells with a kiss of death to self-destruct, potentially reducing the viral load in your body. T cells also leave behind memory cells. Pre-existing specific T cells, which are likely remnants of a previous coronavirus that caused seasonal colds (not COVID-19), may explain milder infections in some people.
B cells are antibodies that recognize a virus by remembering the different parts of different germs. Once memory B cells are activated and localize a particular virus such as COVID-19 and its location, a particular antibody specific for that virus can be intensively produced.
This production takes days to weeks, but the antibodies and memory B cells that are produced persist after the virus is gone. That being said, if you get infected with the same virus later, your body can react quickly and neutralize the virus without developing severe symptoms.
So the point of vaccination is to produce potent antibodies that give us a protective immunological memory. History shows that vaccines were able to eradicate infectious diseases from the planet (such as smallpox).
Pfizer and Moderna use messenger RNA / mRNA-based technology as main ingredients in vaccines. As we know, mRNA is a type of molecule whose job it is to carry copies of genetic instructions (imagine a shopping list or prescription) through a cell to direct the assembly of coronavirus ‘spike’ proteins. This mRNA is only responsible for part and not for the entire virus itself. It is therefore harmless, but sufficient to get your body to respond.
Pfizer also notes that its vaccine is “preservative-free” or free of a well-known preservative called thimerosal, which contains mercury to kill contaminating bacteria in vaccine bottles. This mercury-based preservative has long been an issue of whether vaccines cause autism. The Pfizer vaccine does not contain microchips either.
Language is important when it comes to vaccines. Scientists are often frustrated when the media doesn’t appreciate or differentiate between terms.
Stamataki emphasized that the word “efficacy” is a carefully chosen word used to describe the performance of a treatment under ideal VS-controlled conditions. For example, Pfizer reported 95 percent effectiveness, meaning that its vaccine prevented COVID-19 symptoms in 95 percent of those who received the vaccine compared to a placebo group who did not receive any vaccine or irrelevant / known vaccines should not work for the target virus. For COVID-19, safe vaccines with at least 50 percent effectiveness are expected to be approved by the U.S. Food and Drug Administration.
According to The Lancet Pfizer and Moderna, AstraZeneca and the Oxford Vaccine Group reported an interim analysis of 94.5 percent efficacy, up to 90 percent efficacy and an acceptable safety profile for their vaccine candidates.
How about the effectiveness of the vaccine? That number is unlikely to reach 90 percent and we don’t yet know how effective the vaccine will be overall at reducing COVID-19 symptoms, severe infections or deaths over several years through observational studies (vaccine performance for different groups) to prevent ie age, ethnic origin, other health conditions; Term of protection), said Stamataki.
A group of researchers at the Cambridge Institute for Therapeutic Immunology and Infectious Diseases recently reported a new variant of SARS-CoV-2 (the coronavirus that causes COVID-19) that may have arisen as a result of immune selective pressures in infected individuals. This new variant has increased infectivity and transmissibility and is responsible for a recent surge in COVID-19 cases in the UK and some parts of Europe.
SARS-CoV-2 is an RNA virus with a mutation rate of almost one mutation per month, but mutations accumulate over time and the virus evades recognition by antibodies and immune cells by changing some of its characteristics. The mutation is triggered by error-prone processes when the virus replicates. This happens randomly so it cannot be predicted whether the virus that accumulates mutations over time is more or less dangerous / contagious.
Fortunately, we are able to maintain surveillance to adjust our vaccines as we have tools to keep up with new information from the virus using various genetic sequencing methods (i.e. changing the vaccine prescription). The continued emphasis on testing / tracing remains essential along with the global vaccination effort.
A vaccine is definitely not the end, and antiviral drugs used to treat COVID-19 are not a substitute for vaccination either. In addition to getting a COVID-19 vaccination, people should continue to use the same preventive measures every day: wear masks, cover coughs and sneezes, wash hands frequently, and minimize physical contact to avoid infection and prevent transmission.
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PhD student in environmental microbiology and biotechnology at King Abdullah University of Science and Technology in Saudi Arabia