In late October 2020, a news began to flow on mainstream about Pfizer. This article is intended to describe about Pfizer, it’s history and more importantly how does a vaccine work against COVID-19?
Yeah, it has already been a year since the outbreak of the novel corona virus. Infecting about a 67.6 million people with a death toll of 1.54 million worldwide [1] , this pandemic situation has become one of the worst events in human history. Scientists and all the health work force have been fighting with this pandemic since day 1. Corona Virus are not the new virus that human have encountered. Corona virus actually represent to a large family if RNA virus that causes diseases in mammals and birds. Earliest cases of corona virus date back to late 1920s in North America.[2] Severity of Corona virus ranges from mild, moderate to severe. More severe virus involves MERS, SARS and recently COVID-19. This new strain of virus was unknown to human hence took longer time for vaccine development.
Vaccines prepare the immune system, getting it ready to fight disease-causing organisms, called pathogens. A vaccine is introduced to the body to mimic infection, triggering the body to produce antibodies against the pathogen, but without causing the illness. Conventional vaccines usually contain a weakened or inactivated pathogen; or a piece of a protein produced by the pathogen, called an antigen.
How does a vaccine work against COVID-19 ? | Pfizer Edition
RNA vaccines are a new generation of vaccines. Instead of the antigen itself, RNA vaccines contain a messenger RNA – mRNA – that encodes for the antigen. Once inside the body’s cells, the mRNA is translated into protein, the antigen, by the same process the cells use to make their own proteins. The antigen is then displayed on the cell surface where it is recognized by the immune system. From here, the sequence of events is similar to that of a conventional vaccine. Some RNA vaccines also contain additional mRNA coding for an enzyme, which, after being translated in host cells, can generate multiple copies of the antigen-encoding mRNA. This essentially amplifies the production of antigen from a small amount of vaccine, making the vaccine more effective. These are called self-amplifying RNA vaccines. RNA vaccines are easier and safer to produce than conventional vaccines. This is because mRNA molecules can be synthesized in a cell-free system using a DNA template with a sequence of the pathogen; while conventional vaccines usually require a more complicated and risk-prone process of growing large amounts of infectious pathogens in chicken eggs or other mammalian cells. Without the risks of being contaminated by infectious elements or allergens from egg cultures, RNA vaccines are also safer for patients. Because protein synthesis occurs in the cytoplasm, RNA molecules do not need to enter the nucleus, so the possibility of them integrating into the host cell genome is low. RNA strands are usually degraded by cellular enzymes once the protein is made. The relative simplicity of the production process makes it easier to standardize and scale, enabling rapid responses to emerging pandemics. Other advantages include lower production costs, and the ease of tweaking RNA sequences to adapt to rapidly-mutating pathogens. On the minus side, it can be challenging to deliver mRNA effectively to the cells, since RNA sequences and secondary structures maybe recognized and destroyed by the innate immune system as soon as they are administered intravenously. These limitations can be overcome by optimizing codons, using modified nucleosides to avoid recognition, and packaging RNA into protective nanoparticles. Another disadvantage is that most RNA vaccines require uninterrupted refrigeration for transportation and storage, which can be a hurdle for vaccine distribution. Research is ongoing to engineer thermostable vaccines.
Table of Contents
What is Pfizer?
It is undoubted till now that Pfizer is a mRNA vaccine that work against COVID-19 that have shown 90% efficiency in the clinical trials has been authorized by the UK medicines regulator, making the UK the first western country to license a vaccine against the disease with 40 million doses order for UK.[3]
What if COVID-19 virus mutates, will Pfizer fail?
Pfizer is a new generation of vaccine. Unlike conventional vaccine, it is mRNA vaccine that are easier and safer to produce. Yes, the current dose will lose its effectiveness but The new Pfizer vaccine dose can be designed accordingly to the mutation incase the virus mutates. mRNA technology enables to develop vaccine at faster pace and be completed with in weeks or less.
How much does it cost?
Pfizer is said to be distributed with the marked price of $19.50/dose. Pfizer requires two does regimen hence, account a sub total of $39/vaccine.[4] This price when converted to rupees will be Rs 2296 per dose [ Straight Conversion 1$ = Rs 117.71]
Pfizer and its Prospects in Nepal
Pfizer is gaining recognition after early November 2020. The vaccine effectiveness and its UK approval are impressive and undoubtedly Government will initiate measures to bring this vaccine to Nepal. Despite to effort, at the end it comes to the purchasing power, availability and cost. Nepal may also prioritize other vaccine source incase Pfizer become expensive than others. Addition to this, Nepal has been scheduling 4 vaccines for clinical trials in the country. [5]Sputnik-V” developed by Russia , Covidshield and other 2 vaccines from China and Australia. Taking this account, purchase and use of Pfizer is possibly low. For now , we can hope to have a sustainable plan for vaccine procurement to win this COVID-19 battle.
In a nut shell,
How does a vaccine work against COVID-19 ? | Pfizer Edition
References .
Worldometer Covid-19 dashboard,[https://www.worldometers.info/coronavirus/?utm_campaign=homeAdvegas1] accessed at Dec8,2020
Estola T (1970). “Coronaviruses, a New Group of Animal RNA Viruses”. Avian Diseases. 14 (2): 330–336. doi:10.2307/1588476. ISSN 0005-2086. JSTOR 1588476. PMID 4316767
https://www.theguardian.com/world/2020/dec/02/how-does-the-pfizerbiontech-covid-vaccine-work-and-who-will-get-it
How much will Vaccine cost , Forbes [https://www.forbes.com/sites/katiejennings/2020/11/17/how-much-will-a-covid-19-vaccine-cost]
Govt holding discussions to procure Pfizer vaccine claimed to be over 90% effective,Republic Nepal [https://myrepublica.nagariknetwork.com/news/govt-holding-discussions-to-procure-pfizer-vaccine-claimed-to-be-over-90-effective]/
-Nepal Health Magazine
Hey there, I am Nirdesh Baral, founder of Nepal Health Magazine. I am a Tech geek by passion , Public health practitioner by profession and an Ailurophile by heart and a patriot by birth