Three vaccine frontrunners
SUDDENLY, there seems to be many Covid-19 vaccines being released all at once. What are they?
There have been three major Covid-19 vaccines announced so far.
It is easier to remember them by which company they are from: namely, Pfizer/BioNTech, Moderna and AstraZeneca in partnership with University of Oxford in the United Kingdom.
Right now, these three companies hope to get their respective vaccines approved by the relevant regulatory bodies and roll them out to the world before the end of the year, or at the latest by early next year.
This is very exciting! But I thought that other vaccines have been announced as well, including from Russia and China?
That is true. But these three vaccines are the first that have been through a massive clinical trial process that is widely accepted by the scientific and medical community worldwide.
We hope that the other vaccines from countries like Russia and China will work as well. However, they have to go through the same clinical trial and vetting process for us to be really sure.
Vaccines not only have to be efficacious, but they also have to be as safe for the general population as possible.
That is why it is important to have that worldwide scientific testing and vetting.
OK, back to these three vaccines – are they all the same? Actually, they are not.
The Pfizer/BioNTech and Moderna vaccines involve injecting part of the SARS-CoV-2 virus’ genetic code (comprised of RNA, or ribonucleic acid) into a person’s body.
Two doses, spaced between three to four weeks apart, are needed for these vaccines to be effective.
Each vaccine trains our body’s immune system to recognise the virus if it enters our body and fight against it.
The AstraZeneca/Oxford vaccine is different.
It is a genetically-modified virus of the type that usually causes the common cold and which often shows up in chimpanzees.
This virus has been genetically altered to introduce SARS-CoV-2 viral proteins into our human immune system, which will enable
the immune system to recognise the SARS-CoV-2 virus if it enters our body and fight against it.
And don’t worry, the virus vector is modified such that you won’t develop the common cold.
Which one of these is the best?
All three of them appear to be very effective.
The Pfizer/BioNTech and Moderna ones report 95% efficacy, which means out of every 100 people injected, 95 will be protected.
The Moderna vaccine has data to suggest that it is equally effective across all ethnic groups.
AstraZeneca/Oxford’s vaccine meanwhile has reported an average efficacy of 70%, but only because they have two groups receiving different doses.
The efficacy was 62% when the volunteers were given two full doses of the vaccine.
But when they were given a half dose, followed by a full dose, the efficacy was 90%.
I have heard that there are differences in the storage of the vaccines?
Yes.
The Pfizer/BioNTech vaccine has to be stored at -70°C, which means that you need to transport and keep it in special deep freezers so that it won’t go bad.
That will be a logistical challenge for many countries, including ours, especially with the tropical heat.
It is also very expensive to buy and maintain so many deep freezers.
The Moderna and AstraZeneca/ Oxford ones can be stored in ordinary refrigerators, like the ones we have at home.
That would make it a lot easier to transport and keep.
I am afraid of getting vaccinated. Are there any side effects? What if I get Covid-19 instead?
You will not get Covid-19 from the vaccines.
The virus in the vaccines is incomplete and has been modified so much that it cannot cause disease any more.
Only very mild to moderate side effects, and no serious ones, have been reported so far.
How much will those vaccines cost?
Certain governments with universal health coverage will pay for their citizens to get vaccinated for free.
Some insurance policies will cover the cost.
Even if we have to pay for the vaccine out of our own pocket, it will be a small price for so much benefit.
AstraZeneca/Oxford has stated that its vaccine will be sold at USD3-4 (RM12.26-16.35).
The Pfizer/BioNTech and Moderna vaccines are being quoted as USD20-25 (RM81.74-102.17) to governments.
Will all these vaccines be available to us together or are they being prioritised for certain groups of people?
Different countries will have different ways of rolling the vaccines out.
It also depends on the country’s finances and logistics.
Most countries will prioritise healthcare workers first, as well as people who are at very high risk of getting and dying from Covid-19, such as the elderly.
Dr YLM graduated as a medical doctor, and has been writing for many years on various subjects such as medicine, health, computers and entertainment. For further information, email starhealth@thestar.com. my. The information contained in this column is for general educational purposes only. Neither The Star nor the author gives any warranty on accuracy, completeness, functionality, usefulness or other assurances as to such information. The Star and the author disclaim all responsibility for any losses, damage to property or personal injury suffered directly or indirectly from reliance on such information.