COVID-19: Is a Vaccine Our Only Way To Defeat This Invisible Enemy?
At the start of 2020, countries all over the world went into lockdown in the hope to defeat the ‘invisible enemy’ which has taken millions of lives. COVID-19 is labeled as one of the biggest pandemics the world has seen since the 20th century, perhaps even bigger. Coronavirus disease 2019 is a virus which emerged at the beginning of December 2019 from Wuhan, China. COVID-19 is a strain of respiratory viruses that belong to the Coronavirus family.
Other members of this family include SARs Severe Acute Respiratory Syndrome (SARS) coronavirus and Middle East Respiratory Syndrome (MERS) coronavirus. Unlike SARS and MERS, COVID-19 is highly infectious which means it is more easily spread from person to person. This virus can spread via droplets in the air through coughing, saliva, nasal secretions, and sneezing.
There is a lot of speculation and uncertainty regarding how this virus began to spread. It was initially believed to have come from an illegal seafood market in Wuhan, however, this has recently been disproven. The director of disease control and prevention in China has said that the virus was not detected in the closed seafood market it had suspected come from. So, where did Coronavirus come from? Regardless of whether the virus came from a lab, an illegal bat market, or 5G towers (I don’t believe this BTW), the bigger question is how can we defeat this virus?
Therapeutics: Virus vs Drugs
Vaccines teach the immune cells to recognise specific pathogens so if the individual is faced with this pathogen at a later date their immune system is already familiar with the virus structure. Therefore, the body can make the right antibodies faster. Antibodies bind to the virus and prevent the virus from invading the cell.
There are two types of vaccines, the first type involves using a form of the weakened pathogen, this is known as a live vaccine. The second type of vaccine consists of an inactive pathogen. The latter offers short-term protection where-as the former results in long-term protection i.e. up to 75 years plus in the case of Smallpox, which is also the first disease to ever be eradicated by a vaccine.
Many UK universities i.e. Oxford University, Imperial College London, Cardiff University (proud alumni) to name a few are working on developing a vaccine against COVID-19. On top of this, pharmaceutical companies from all over the world are also investing time, money, and resources to fight this disease that has caused one of the largest global pandemics in history. On January 12th, a laboratory in China sequenced the entire genome of the COVID-19 virus. This was shared with the rest of the world and resulted in a global effort to try and develop a vaccine using this genome sequence.
The process of producing a vaccine involves many steps and the upmost priority is patient safety and ensuring the vaccine is safe in humans with no serious side-effects. For this reason, there are usually several phases involved in vaccine production usually starting with testing the vaccine on animal models first. Altogether, this process can take anywhere from 10–15 years. However, we require a vaccine urgently if we are to defeat COVID-19 and go back to our normal lives.
Several pharmaceutical companies are trying to hurry this process along, the CEO of Pfizer has even claimed that they could have a vaccine readily available by as early as October this year — ‘if all the stars align.’ Perhaps this is possible, perhaps it is wishful thinking.
In China, the first phase 1 trial has already begun back in March for a vector-based vaccine and hundreds of global universities and pharma companies are collaborating together to propel the development of the COVID-19 vaccine along. It would certainly be one of the greatest scientific achievements in history if a vaccine could be developed in less than a year.
As well as vaccines, research laboratories are focusing their efforts on developing anti-viral drugs against COVID-19. Some scientists are currently using drugs already in the market and tweaking them to see if they would also work for COVID-19. For example, Remdesivir originally developed for Ebola is being extensively studied for COVID-19, results have shown symptoms were cut down to 10 days or less (Wang et al. 2020).
Other studies have looked at HIV drugs i.e. Lopinavir which is known to inhibit the activity of protease enzymes in animal studies. It has also been proven to be effective for SARs and MERs. However, in a recent trial by Cao et al. 2020, Lopinavir seemed to produce disappointing results for COVID-19 as it did not improve recovery. Let’s take a quick look at some recent studies and their findings.
In a recent study published in April, scientists tested the effectiveness of Chloroquine in treating COVID-19. Huang et al. treated 10 patients with moderate to severe COVID-19 symptoms and gave the patients 500mg of Chloroquine two times a day for 10 days in total. The scientists used Real-Time Polymerase Chain Reaction (RT-PCR), to test the presence of the virus.
The results showed that one individual had no virus detected after just 2 days. This is promising results for the effect of Chloroquine as a treatment for COVID-19. However, it must be addressed that a limitation to this study is the sample size is very small so it may not be reflective of the whole population. A larger randomized trial is necessary to evaluate the effects of Chloroquine on the Coronavirus.
A controlled open-label trial by Cao et al. studied the effect of Lopinavir or Ritonavir in a 1:1 ratio 2x a day for 2 weeks. Altogether 199 hospitalized patients with severe COVID-19 symptoms took part in the study; 99 patients were given Lopinavir or Ritonavir and 100 patients received standard hospital care.
The results were disappointing as neither of these antiviral drugs showed any benefit compared to standard care. In order to take this study further and improve this study, a large sample size could be used including COVID-19 patients with moderate symptoms.
Remdesivir, as previously mentioned, was developed for Ebola and has gained a lot of excitement with hundreds of studies looking into how effective this drug is for treating COVID-19. A double-blind placebo trial last month by the US National Institute of Allergy and Infection studied Remdesivir in 1063 patients. Severe COVID-19 patients were given either Remdesivir or the placebo for 10 days (200mg the first day, 100mg the following 9 days). The scientists measured the efficacy of the drug based on how many days less the patients taking Remdesivir stayed in the hospital compared to patients given a placebo.
Results for this trial were promising and showed that Remdesivir was efficacious, overall a reduction of symptoms was witnessed and the recovery time was shortened from 15 days to 11. Despite this result, it is also important to note 20% of patients experienced serious adverse effects, and further to this, the method of testing whether the virus was still present was not looked at i.e. using RT-PCR as done by Huang et al.
Another randomized placebo trial by Wang et al. also looked at the efficacy of Remdesivir and found conflicting results to the US trial above. The research involved 237 patients across 10 hospitals, the patients were assigned either Remdesivir or placebo for 10 days.
The results showed that there was no statistically significant difference between Remdesivir or the placebo. However, as this was a much smaller sample size compared to the US trial, these results might not be indicative of Remdesivir’s true efficacy and the researchers also admitted a larger study was required to evaluate Remdesivir’s use as an anti-viral drug for COVID-19.
Finally, I wanted to address the question in the title of this article — is a vaccine our only way to defeat the virus? As you can tell from the anti-viral drug studies there have been promising results published in the last few months showing that there is potential for using drugs already in the market to treat COVID-19. Effective drugs would help people manage their symptoms better, spend less time in the hospital, and possibly reduce mortality. However, it is also important to note that although both repurposed and novel drugs show exciting results, drugs would not stop the virus coming back again.
In order to defeat the virus globally, and avoid second or even third waves of this virus, the best way to defeat the virus long-term is to gain immunity and that can only be done with a vaccine. To conclude, collective approaches to help reduce the spread of the virus is vital, but an effective vaccine would ensure that the worst pandemic in the last century could finally come to end with little to no chance of returning, much like Smallpox.