Creating a Covid-19 vaccine


  • Wellness
  • Thursday, 24 Sep 2020

Russia has approved their homegrown Covid-19 vaccine, despite it not having gone through phase 3 clinical trials. — AFP

I have read so much about Covid-19 vaccines, or rather, about the fact that there is none yet for us. Why is taking so long for a vaccine to be produced?

Vaccines are usually produced against viruses and bacteria.

They are meant to activate your body’s antibody response to this foreign invader, so that the next time your body gets attacked by the same virus or bacteria, your body’s immune response will be very swift in dealing with the impending infection.

But they do take quite long to be created.

This is because the process of creating a vaccine takes several steps.

What are these steps?

First, you have to determine the genetic code of the virus you are producing the vaccine against.

In this case, it is the SARS-CoV-2 virus. Luckily, the virus’ genetic code was cracked very quickly early on.

Then you have to decide which method you want to make the virus inactive/weakened, including:

  • Inactivating the virus while keeping its structural components mostly intact.

    Once inactivated, it will not cause infection.

  • Majorly weaken the virus (to create an attenuated virus).

    The virus will still be alive, but not strong enough to cause an infection.

    Measles and flu vaccines are created this way.

  • Pulling out specific parts of the virus’ genetic code.

    Your body will still recognise parts of the viral genetic code and mount a response.

    Apparently, several Covid-19 vaccines are being created with this method.

Then what happens?

Then you have to do the most important part: the clinical trials.

This part usually takes the longest to complete.

You have to use healthy, normal people who volunteer first.

They will test that the vaccine is safe and will not produce any major side effects.

You are looking for an antibody response once the vaccine injected.

This is a phase 1 clinical trial.

Then you do another round of clinical trials in more and different types of people, like the old, the young, men and women. This is phase 2.

Then you give it to even more people, numbering in the thousands.

This time, you give it to those who are at real risk for infection, such as healthcare workers. This is phase 3.

You compare them with another group who have been given a placebo to see who gets infected and who doesn’t.

Here, you again look for antibody response and safety issues.

This phase takes the longest time.

If that is all successful, then can the vaccine be given to all of us?

Once the clinical trials are complete and statistically successful, then you have to go through the regulatory bodies of each country to approve it for widespread use in that country.

The vaccine is then mass manufactured and given to as many people as possible who need it.

There is still post-monitoring surveillance to look out for possible side effects that may have been missed in the trials.

So where are we on the Covid-19 vaccines? We hear so many things, like there is a Russian vaccine, etc.

As of the time of writing, there are 37 Covid-19 vaccines in different stages of development. Most of them are still in phase 1.

There are also 91 more vaccines in the pre-clinical stage, which are still being tested out in animals.

Is that ethical? Testing vaccines on animals?

That is what many people are arguing about.

But it is how pre-clinical studies are conducted, and not just for vaccines – all drugs go through animals first.

If we don’t test in animals first, then it would be quite dangerous when we test it out on humans.

Would you rather minimise the risk for humans at the expense of animals, or save the animals and create greater risk for the human volunteers?

In fact, if the risk is too great, no one might want to volunteer for these clinical trials, and we might end up with no drugs to heal and save lives, including those of your loved ones.

For me, it is a no brainer. As long as the animals are well taken care of and given the same care and diligence human volunteers get, then we should proceed.

How would a Covid-19 vaccine be considered effective?

The US Food and Drug Administration (FDA) said that a Covid-19 vaccine would have to protect at least half of those vaccinated in order to be considered effective and approved by them.

Moreover, it has to be relatively safe.

So, is the Russian vaccine effective?

The Russian scientists who developed the vaccine have had their phase 1 and 2 clinical trial results published in The Lancet, a very famous and well-respected medical journal.

There was indeed strong antibody response and no alarming safety issues in the volunteers.

They concluded that further investigation, such as a phase 3 trial, is warranted.

No one is really against the Russian vaccine.

Scientists are merely asking for it to be tested in the proper phases as would be required of any other drug or vaccine.

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.

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