Sunday 28 February 2021

Should You Go For Covid-19 Vaccination?

The unprecedented Covid-19 pandemic has been here for one year. I'm sure that almost everyone in the world wants it to end as soon as possible.

Now we Malaysians have a good chance to put all these miseries to bed, as our Covid-19 vaccination program has just started.

However, I find that some of those who are very scared of being infected with Covid-19 virus are reluctant to get themselves vaccinated.

Most of them want to wait and see first (if someone die from vaccination).

I think that this kind of mentality is common, probably due to influences of "news" from social medias which have been widely shared and circulating around.

"Four people died after vaccination", "XX country reports 30 death after vaccination", "Doctor or nurse died a few days after vaccination", "Someone paralyzed after receiving the jab" and so on.

For those pure headlines readers, they would probably be very scared of Covid-19 vaccines. However, if we read further, it's actually nothing to be worried about, at least until this moment.

Many people are dying everyday in the world even without Covid-19. It might just be a coincidence that their death occur soon after vaccination.

"Young and healthy" people also can suffer sudden death. Haven't you heard of such incidence that someone relatively healthy collapses while playing badminton or hiking, or die during sleep?

If such group of unfortunate people get the vaccination a few days or weeks before, can we relate the vaccine to their death?

It's just like when someone die unexpectedly and he happens to take durian with beer the day before, then people will "confirm" that taking durian with beer is fatal and has to be avoided at all cost.

Is it logic? If it's true then why thousands of other people who take durian with beer don't die?

Such dispute can only be settled with an experiment. We can ask 50,000 people to take durian with beer, and another 50,000 persons to take durian with plain water. Then, we observe how many people in each group die within one week.

You might wonder why must we include those people who drink plain water? It is called a "control group" or "placebo".

If we only ask 50,000 people take durian and beer without the control group, and 200 out of 50,000 die within one week, can we conclude that taking durian with beer increases our risk of dying?

If you think it's unlikely as it's only a very low 0.4% fatality rate, then how much % is needed to conclude that taking durian with beer kills? Is it 1%, 5% or 10%?

Obviously we can't come to an accurate conclusion, as we don't compare with the death rate of normal population.

That's why the control group comes into play. Let's say out of 50,000 persons in the control group who take durian with plain water, 210 of them die within one week.

So, in this experiment, 200 people die after taking durian with beer, while 210 people die after taking durian with plain water. It's clear that taking durian with beer won't make you die faster.

If this experiment is done and published, the press and medias will probably put this as headline: "Research shows 200 people die after taking durian with beer!!!". It's a powerful click bait!

That's the same thing with Covid-19 vaccines.

In everything, there are surely someone who are against it. There are anti-vaccine groups who refuse to take any kind of vaccines, not only the Covid-19 vaccines.

Ironically, some of them might be healthcare professionals. They will give you lots of reasons that you should not take the vaccines.

We are bombarded with so much information, either pros or cons. So who should we listen to?

Here I'll show you the Pfizer-BioNTech vaccine trial and you can make your own decision.

Probably you'll still remember that in mid Nov20, there was an announcement that Pfizer-BioNTech Covid-19 vaccine is 95% effective.

What does this 95% mean?

In this experiment (vaccine efficacy trial) using Pfizer-BioNTech vaccine, 21,720 people received the vaccines while 21,728 people received saline or "salt water" injection. The saline injection acts as a control group.

All of these 43,548 people and even the healthcare workers who perform the injections do not know whether they get the real vaccine or normal saline.

There are 2 doses for this Pfizer-BioNTech vaccine and saline, which are given 21 days apart.

To make things simple, we just go straight to the results.

First we look at the numbers below the line graph which shows the number of confirmed symptomatic Covid-19 cases between the vaccinated (BNT162b2) and control (Placebo) groups.

Those figures show that the vaccine offers protection as soon as dose 1 is administered, even though our body might take up to 2 weeks to mount a good immune response.

After dose 1 to before dose 2 (which is 21 days apart), 39 people in the vaccine group are infected with Covid-19 while 82 people in the control group are infected. So it has 52.4% efficacy after taking dose 1.

The most important period of this trial is 7 days after dose 2 when the vaccine should have mounted a good immune response. Only 9 people who get the vaccine are infected at this period of time while as many as 172 of those who are injected with salt water are infected.

Thus, its efficacy at the period of time is as high as 94.8% [(172-9)/172], which is extremely good.

Although the vaccine can't be 100% effective, those who got the vaccines and are infected tend to have less severe infection.

Nevertheless, the data are based on median time of 2 months follow up after dose 2 injection, with the longest follow up until 3.5 months. This trial will continue up to 2 years after dose number 2.

Even though the time of study is short, the efficacy of the vaccine is very obvious as shown by the figures in the chart above.

We can see from the line graph that the blue line (control group) keeps climbing up with time but the red line (vaccine group) stays low.

It's like the share price chart of UWC vs Uchitec.

If nothing unexpected happens, the two lines are expected divert further from each other with time.

Personally I'm convinced that this Pfizer-BioNTech Covid-19 vaccine is effective. However, is it safe?

This is the reason why most people don't want to get vaccinated, isn't it?

We won't talk about minor temporary adverse effects such as fever, headache, pain & swelling at injection site etc. Surely those people injected with vaccine will have more of such issues as the vaccine triggers our immune system to produce antibodies.

We want to know how many people die.

With the follow up of median 2 months and some up to 3.5 months, 2 people in the vaccinated group died of heart disease, while 4 people in the control group died (one heart attack, one stroke and 2 unknown reasons). 

There is no increase of death in vaccine group compared to control group, and the 2 death were concluded to be not related to the vaccination.

Thus, Pfizer-BioNTech Covid-19 vaccine is very unlikely to cause death or other serious medical condition in 2-3 months time after completed 2 doses.

The limitation is that we don't know about it after 3 months, 6 months or even 1 year. Can many of those getting the vaccines suddenly die 6 months after vaccination? 

No one knows but personally I think it's highly unlikely.

Will the vaccine make us prone to other illnesses after 20-30 years? No one can give us a definite answer as well. 

There is a risk in everything we do. Cigarette smoking is confirmed to cause lots of deadly health conditions but there are still many smokers around.

Israel is one of the earliest country to start mass vaccination program since mid Dec20. It's reported that until 1st Feb21, the Pfizer-BioNTech vaccine reduced symptomatic Covid-19 cases by 94% a week after the second dose, and reduced severe disease by 92%.

The vaccine efficacy matches the figure of Pfizer-BioNTech own trial.

The vaccinated group in Israel is large at 600,000 people. It has been shown to be effective against the UK mutated strain too, which also matches the initial in-vitro study finding by Pfizer-BioNTech.

Sceptics might say that there is data manipulation in the research in order to pass the vaccine so that the company can win the vaccine race to earn big money. Well, I can't be 100% sure and it's all up to us to judge by ourselves.

Many of those who are confirmed positive for Covid-19 infection do not expect they will ever get it.

If you delay the time to get vaccinated, who knows you might get infected when you should be able to escape if you get vaccinated earlier.

You might think that you will recover well as you are still young and healthy. However, you might spread the virus to your love ones and may be some of them might end up in ICU.

So, don't just listen blindly to someone who tells you that Covid-19 vaccines are "dangerous". Don't just make a conclusion base on the sharing on social medias with just some frightening headlines.

I suggest you to get the opinion from healthcare professionals, as they are the most qualified persons to give you good advice on this matter.

Lastly, I haven't keep track on Covid-19 new cases in the world for quite some time, and I am a bit "shocked" to see that the new cases in US have dropped so dramatically, as almost 20% of its population have received at least one dose of the vaccines until today.

No comments:

Post a Comment