How long must we wait for a COVID-19 vaccine?

As part of our special coverage on the COVID-19 outbreak in the Northeast, we are publishing this article by Dr. Yutthana Pongsom, a physician who is familiar with emerging infectious diseases. He looks at the timeline for the development of a vaccine against COVID-19.

By Yutthana Pongsom

When I was studying to become a doctor, one of the ways of getting some extra income as a student was to be a guinea pig for new vaccines. I once agreed to get a hepatitis vaccine in its trial stages tested out on me. After it was injected into me, I had to submit to regular blood tests to monitor my immune system. My fellow vaccine testers and I would compare results with each other, to see whose immune cell count was the highest.

The trial that I participated in was the second stage of a clinical trial to test the effectiveness and side effects of a vaccine on a small sample of people. It wasn’t until five to six years afterwards that the vaccine was finally ready for the general public, and is still in use today.

Vaccines are one of the most important tools we have in the fight against viruses. As the COVID-19 pandemic continues, the main hope for decisively checking its advance now lies with the development of a vaccine. We have already seen how effective a vaccine can be from the way that the 2009 H1N1 virus outbreak was contained by an effective vaccine.

Over the past weeks, the UK authorities put out a call for volunteers to help test a COVID-19 vaccine. Although they received over 10,000 responses, only 24 volunteers were selected for the trials. These volunteers will receive 4,000 pounds each, or roughly 161,000 baht [as per the exchange rate at the time of writing] in compensation.

The vaccine development is still in its very earliest stages because they must start by deliberately infecting the test subjects with a milder strain of coronavirus. This method is used to closely observe and understand the effects of the vaccine on the human immune system in order to design a vaccine in following stages.

Make no mistake. It’s going to take a while for the vaccine creators to digest the findings from the volunteers. It appears that the Israel Institute for Biological Research (IIBR) had pulled ahead of the UK in announcing significant progress in developing a COVID-19 vaccine. Yet further animal and human testing is still required, which makes it many months before the general public could access a viable vaccine.

So far, the vaccine creation effort that appears to be making the most progress is that of the National Institute of Health in the US. They are currently testing their vaccine prototypes on 45 volunteers in partnership with the biotech company Moderna Therapeutics.

The volunteers will receive a total of two vaccine injections in their arms over the course of 28 days. Meanwhile, researchers will be keeping a close eye on what transpires in their bodies. They will be especially vigilant for what happens when the volunteers experience fever, aches, or any kind of allergic reactions. This data-gathering stage lasts six weeks.

This is considered a “stage 1 clinical trial” where the basic safety and correct dosage of the vaccine is gauged. If the immune systems of the volunteers are unable to successfully develop immunity with the aid of the vaccine during this round, the trial will have to start again with a revised dose or frequency.

The development of a new vaccine can be split into two phases; the pre-clinical trial stage and the clinical trial stage. Each of these two phases contain many different stages and milestones that have to be met before proceeding further.

The clinical trials that involve human testing can be divided into three stages.

In stage 1, the goal is to gauge the safety of the vaccine, to test its ability to stimulate the immune system, and to determine the correct dosage. This usually requires a sample size of 20 to 80 test subjects.

In stage 2, several hundred more subjects than used in stage 1 are used for testing the vaccine This is because some of the test population will serve as a control, or people who receive no vaccination, in order to objectively compare against the results of stage 1 testing.

Stage 3 is where testing at a scale of tens of thousands of people is required. This can be likened to field testing where the vaccine’s safety and its ability to upgrade the immune system is observed.

Every single stage requires meticulous standardized monitoring.

The World Health Organization (WHO) is also providing close support to various organizations that make vaccines to ensure that when a viable vaccine is available it can be readily produced all over the world.

When a pandemic occurs, the WHO gives virus strains to its production partners so that they may produce the vaccine. The producers are then licensed to make the vaccine on condition that they dedicate seven to percent of their production capacity for the WHO’s stock of vaccines. The WHO uses this stockpile to distribute vaccines to countries which are incapable of producing their own vaccines.

Only when a prototype vaccine has passed the tests for safety, efficacy, and quality assurance can it then go on to the clinical trial stage. It takes about three months after receiving the target virus strain to prepare the vaccine for human testing. A three-stage clinical trials process then commences, and takes about another three months. That’s at least six months until a viable vaccine that can be administered to the general population.

The pharmaceutical factories which are to produce these vaccines must also be ready for production. This could involve some significant changes to their production set-up. It could take up to a whole year for each of these factories to reach full production capacity for a completely new vaccine, in order to meet the demand of billions.

Having said that, the above timelines are based on the collective experience in creating a vaccine for the 2009 H1N1 virus, which occurred quite some time ago. Taking into account the capabilities of the companies involved in developing the vaccines for the H1N1 2009 virus, together with the technology available today, it may take less than 18 months to produce a COVID-19 vaccine for the public

Even though it is estimated that we will be able to produce the vaccine faster than the rate of contagion, we must still guard against infection while we wait for the vaccine. The best way to do this is to maintain social distancing and forego all non-essential travel.

If we were to compare this pandemic to a war, it would be as if we were under siege. We are showing our fortitude by staying indoors to avoid danger, while we wait for relief to arrive. If we sally out before the vaccine is here to relieve the siege, we risk defeat at the hands of the virus. Because if we become infected, it will already be too late for the vaccine to help us.

This article was first published in Thai on March 31, 2020. Translated and edited by The Isaan Record.

Scroll Up