By Jude Holmes
The first cases of COVID-19 in humans were recorded in the city of Wuhan in December 2019. By the end of January, the World Health Organisation (WHO) had issued a Public Health Emergency of International Concern, a warning for all countries to prepare for the spread of the virus. On the 11th of March, this warning was increased to a declaration of a global pandemic. Governments across the world scrambled into action; delivering lockdown mandates for residents, raising funds to build hospital facilities and supply PPE, as well as assembling leading scientists in the search for a cure.
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In March, the papers were filled with promises of a world record breaking vaccine within 12 months. However, vaccines for contemporary diseases such as Mumps and Ebola took four to five years between initial viral testing and licensing for commercial use. At the time of writing, approximately 32 million cases of Covid-19 have been recorded in humans worldwide. Although the spread has slowed with lockdown measures, the easing of those measures has caused a predictable second wave of cases and this number will continue to rise until we find a vaccine. Without worldwide prevention, the consensus is that we cannot return to our old way of life. So how long will humanity be stuck on hold?
Options On The Table
Different types of vaccines are being tested by research departments across the world. Some use a “whole virus” vaccine approach, using a dead or weakened strain of the virus to promote an immunity response from our cells. This reduces the need for time and money spent creating a new compound, however, there is increased risk of the patient receiving symptoms of illness. Other vaccine types try to target proteins that are useful to the virus, in this case the virus attaches itself to the “spike protein”, if we could change the shape of the protein, then the virus cannot “dock” as easily onto our cells and cannot spread through the body. However, if the virus cannot use the protein, neither can our body which can lead to unwanted side-effects. A third option is to reuse the antibodies tested in the SARS outbreaks, as these have already undergone testing in humans and SARS and COVID are related viruses. However, they are distinct viruses and testing must show a good rate of virus neutralisation. Finally, the vaccine could contain DNA or RNA structures which, when injected into the body, start to make the proteins that fight infection, currently a technique only applied in veterinary medicine.
Passing The Test
There are multiple stages of testing for vaccines. Preclinical testing is the first stage where a vaccine is first tested on cells within a laboratory for promising results. Animal testing is then done to test for an immune response. Phase 1 Safety Trials then begin on a small number of humans, testing for safety, dosage and immune system response. Phase 2 is an expanded trial on hundreds of people, often branching into children and adults to mark any differences in vaccine presentation which could lead to a dosage change for these groups. Phase 3 Efficacy Trials see thousands of people vaccinated and monitored compared to a placebo. The FDA is looking for a protection rate of at least 50% to confirm effectiveness. At each stage, testing is continued for immune responses and side-effects are monitored, as rarer problems might be flagged at this stage. To make things quicker, multiple stages may have overlaps, such as rolling out the vaccine to more test subjects in Phase 3 before receiving the final analysis of Phase 2 data. The final stage is approval and usually requires a multinational review of trial results by defined regulators. The drug can then be licensed for use, where it will still be monitored as the general population begins to access the vaccine. During a crisis such as this, emergency use authorisation can be obtained to begin the mass distribution of a drug.
However, China and Russia have approved vaccines without verifying the Phase 3 trials. This risky strategy might pay off in terms of the general population, however the potential for severe or even life-threatening side-effects could result in an overall worse outcome.
This process might seem overly cautious, but it is based on our history of vaccine research. Early SARS vaccine hopefuls only showed unwanted immune responses in certain mammals, not flagged in the tests on mice. Our history with this kind of discovery has given us the reasoning behind the slow process of the vaccine development, there is a balance between the urgency for a solution and ensuring safety by meeting requirements. The “measure twice cut once” approach is discussed in detail in this Nature article. But what about the trials started 42 days into research? Well it turns out that the vaccine compound was developed in the 90s, has been tested on humans in multiple vaccine hunts and so far hasn’t been useful in any of them, it just hasn’t caused any harm.
Is Any Price Too High?
Do we need a vaccine? In the UK, the rate of infection is high, coronavirus spreads easily, and the headache of track and trace is leaving much to be desired. Despite all this, however, the fatality rate is comparatively low. This means a high amount of the population would have to be vaccinated at the same time to effectively stop the spread to the vulnerable groups. This can be somewhat of a logistical nightmare, especially when we don’t want people heading in droves anywhere, even if it is for a vaccination appointment. However, we also don’t have data on the long-term effects of Covid-19 and with reports of some healthy people becoming unwell for months with fatigue, herd immunity might be riskier than it first seems. The balance for now will be containing the virus in the boundaries of what our medical care can support, giving us more time to understand the data and hopefully find a vaccine. For a full timeline of current vaccines and their progress, you can check out a comprehensive tracker by the New York Times here.
Jude Holmes is a staff writer at The International. Find her here on LinkedIn.