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Despite scientists forecasting for years that new viruses will continue to emerge, the world was not prepared for Covid-19. We must not wait to be surprised by the next zoonotic coronavirus, but work to identify the next threat, argues Professor Miguel Quiñones-Mateu.
Humanity has been facing microbial diseases throughout history. We have been, and continue to be, exposed to a multitude of microbes, from bacteria, fungi, and parasites to the sempiternal viruses since day one.
Yet two years ago, when SARS-CoV-2 arrived, the world was not ready for it. We must now stay one step ahead of nature, in preparation for the next coronavirus outbreak.
Many of the microbes are innocuous to humans and, in many cases, we have been able to coexist and evolve with them. Nevertheless, microbes have been responsible for a few notable pandemics during the last few centuries, starting with the Black Death – caused by the bacterium Yersinia pestis – in the mid-1300s, to the influenza virus A/H1N1 virus responsible for the 1918 Spanish flu.
In fact, novel viruses have been responsible for all of the most recent epidemics: the Asian flu (influenza virus A/H2N2 virus, 1957-58), the AIDS epidemic (Human Immunodeficiency Virus, 1981-present), the Swine flu (influenza A/H1N1, 2009-10), the Ebola epidemic (Zaire ebolavirus, 2014-16), and the Zika epidemic (Zika virus, 2015-present).
For years, the scientific community has been forecasting that new viruses will continue to emerge, perhaps more frequently in the near future. Based on recent history, most experts, including New Zealand’s own Dr Robert G. Webster, have predicted that a new influenza virus capable of being transmitted among humans would be responsible for the next viral pandemic.
Fast forward to the end of 2019, not many people could have anticipated that a new coronavirus, and not an influenza virus, would be responsible for one of the major pandemics of the last 100 years.
With more than 255 million confirmed cases and over 5 million deaths worldwide to date, the Covid-19 pandemic has taken the world by storm. SARS-CoV-2 emerged in Wuhan, China in December 2019, most likely transmitted to humans from bats. This is not that dissimilar from previous zoonotic events associated with other coronaviruses.
SARS-CoV and MERS-CoV emerged in 2003 and 2012, respectively, with bats being the original source of the viruses in both cases. Although less pathogenic than its predecessors, SARS-CoV-2 is more easily transmitted than SARS-CoV and MERS-CoV, one of the main reasons for the havoc this virus has caused around the planet.
Imagine having a blank canvas of close to eight billion people to infect, with basically nothing to stop it while still adapting to replicate in the human host. This virus has arrived and will remain with us for the foreseeable future.
While a swift global response has led to the development and deployment of safe and effective SARS-CoV-2 vaccines, as well as a massive effort to develop highly effective anti-SARS-CoV-2 drugs, it is clear this may not be the last coronavirus outbreak we will see this century.
It seems like since the advent of the “original” SARS-CoV in 2003, the world has seen a new coronavirus “jumping” from animals to humans approximately every 10 years.
Climate change, deforestation, more invasive agricultural practices and easy migration will continue to favour these zoonotic events. Therefore, we need to be not only aware, but prepared, for the next viral epidemic.
This time, New Zealand’s privileged geographic location allowed us to observe and learn from the initial effort by researchers, clinicians, and public health officers around the world, and their attempt to contain the initial viral outbreak.
We were able to design and put in place a comprehensive plan to contain this new virus, which was spreading more easily than the last two “new coronaviruses”.
A combination of public health measures, establishment of diagnostic capabilities, as well as basic and translational research programs, together with an exemplary response from the community, allowed the country to control the initial virus outbreak.
However, the current Covid-19 pandemic is the most recent consequence of global amnesia, where similar outbreaks caused by previous coronaviruses gradually ended and were rapidly forgotten by the public.
SARS-CoV-2 arrived almost two years ago and the world was not ready for it. Therefore, we should not be waiting to be surprised by the next zoonotic coronavirus, but rather working on identifying the next threat.
One way to be one step ahead of nature, is to characterise novel coronaviruses from bats and other mammalian species, as well as preempting coronavirus evolution.
Like other coronaviruses, SARS-CoV-2 is able to accumulate mutations. However, the ability to correct mistakes during viral replication limits its antigenic drift, which is considerably lower compared to other RNA viruses, such as Human immunodeficiency Virus (HIV), Hepatitis C virus (HCV), or influenza virus.
On the other hand, coronaviruses have mastered the exchange of genetic material between two related coronaviruses by recombining their genomes during RNA replication.
In fact, it is this ability to “stitch” together pieces of genomes from two or more different viruses that usually lead to the generation of novel viral variants or even new viruses, which may have acquired the ability to replicate in human cells – the perfect storm for a zoonosis event.
Our laboratory at University of Otago is currently working on a multidisciplinary project, in collaboration with several national and international groups, with the goal of identifying new coronavirus spike proteins (responsible to recognise and invade susceptible cells) with potential human tropism that may emerge in the future.
By doing that, we expect to be able to develop a universal vaccine for the current Covid-19 pandemic and, equally important, a jab able to protect us for the unequivocal risk of similar coronavirus outbreaks in the future.
*The author declares that he has no conflict of interest
