A new virus born from an animal to human crossover. A worldwide spread that prompted the World Health Organization to declare a pandemic. Thousands of people from countries all over the world, from North and South America, Europe, and across Asia, infected by this novel respiratory virus. Then eight months, the pandemic was concluded, and signs of the virus fast fading from public memory. By the end, the total count was over 8000 infected and 774 dead. This was the 2003 SARS epidemic, often referred to as the first pandemic of the 21st century. We have now just passed the one year anniversary of the COVID pandemic and it couldn’t have been a more different experience than the 2003 SARS outbreak. What made the two viral outbreaks so different? And can this information help protect us from future outbreaks?
In 2002, the first case of atypical pneumonia was reported in the Guangdong province of southern China. It is thought that the virus likely was transferred from horseshoe bats, which were commonly sold in Chinese wet markets in 2002, although confirmation of exactly what type of animal hasn’t ever been made. And very similarly to COVID, by early March 2003, the World Health Organization issued a global alert for a severe form of pneumonia of unknown origin spreading around the areas of China, Vietnam, and Hong Kong. By the end of the month, the Center for Disease Control was utilizing and enacting pandemic planning policies.
Like COVID, severe acute respiratory syndrome or SARS is a type of coronavirus. SARS usually begins with a fever and grows into mild to severe respiratory symptoms, with most patients developing pneumonia. 10-20% of patients also develop diarrhea. And again, similar to COVID, SARS was primarily spread by close person-to-person contact, usually through respiratory droplets like coughs or sneezes. It can also spread through a person touching a contaminated surface or object and then touching his or her mouth, nose, or eyes. Compared to COVID, SARS was much more lethal, killing 1 in 10 infected.
SARS shocked the world as it spread swiftly from continent to continent, leaving a devastating wake on local and regional economies. From February to June of 2003, Guangdong recorded 1511 cases and 57 deaths. By the end of June, mainland China had a total of 5329 cases with 336 reported deaths. In that same period, Hong Kong saw a total of 1750 cases and during the same period, 286 people died of the virus. In Canada, there were a total of 251 infected with 44 deaths. Vietnam saw 63 cases with six deaths. And in the U.S., there were a total of eight confirmed cases, and no deaths.
After a year of COVID, these numbers may seem small in comparison but in 2003, countries across the globe were enacting travel restrictions and hospitals were quickly acting to try and contain the spread of this virus. And they succeeded. By July of 2003, the virus was contained and no new cases were reported. This success was achieved by prompt isolation of patients, strict enforcement of quarantine of all contacts, and in some areas, community-level quarantine, and careful surveillance of recognized cases.
So after this kind of eerily similar experience, why weren’t we better prepared for COVID-19’s arrival? It seemed like SARS very much acted as an early blueprint in how to handle a global pandemic, and even more specifically, a coronavirus pandemic. With this kind of knowledge and real life experience behind us, how did COVID-19 spread so far and so fast?
The reasons behind COVID-19’s spread is actually several pronged. The first is the transmissibility of COVID-19. While SARS was much more lethal, COVID was much more easily transmissible. COVID-19’s epidemiology seems to have a structure that allows for higher infectiousness. R0 is a central concept in infectious disease epidemiology, indicating the risk of an infectious agent with respect to its epidemic potential. A study published in February 2020 found the average R0 of COVID-19 to be higher than that of SARS. This was evidenced from the first documented case of COVID-19 in Dec of 2019 to the 80,000 reported cases by the end of February 2020, despite massive containment efforts. This showcased a much more rapid progression of infections than what was reported for SARS between November 2002 and March 2003, before any forms of containment were even instituted. The easy transmissibility was also heightened by the difference in infectious period between the two viruses. Isolation and quarantining policies were highly effective for SARS because peak viral shedding occurred after the patients were already quite ill. But with COVID, transmission of the virus was possible even during early phases of the illness, before any symptoms arose within the infected. This meant by the time severely ill patients were isolated, it would have been too late. And this kind of easy transmissibility is reflected in the numbers. According to Johns Hopkins University, COVID-19 was able to infect over 140 million people, killing a staggering 3 million. Contact tracing and quarantining become much more difficult to implement when even the infected aren’t aware they are infected.
Another reason for the rapid and wide spread of COVID-19 over SARS was because of the weaker viral persistency SARS had over COVID-19. According to researchers from the University of Milan, after eight hours, no viable virus remains can be found on surfaces like copper or cardboard. And while COVID-19 also dissipated from copper and cardboard after 24 hours, on other objects, the viral remains lasted for days. COVID-19 could be detected up to five days on glass and nine days on plastic. This meant there was a longer window of opportunity for transmission for COVID-19 from someone touching an infected item and then touching their eyes, nose, or mouth.
And finally, another reason for the global outbreak is the happenstance of location and timing. China’s population density has tripled since 2003 and outward travel has doubled in the past decade. Wuhan is also the largest city in central China, with 11 million people residing within its borders. The city is a major transport hub, home to the largest train station, biggest airport, and largest deep-water port in central China. About 30,000 passengers fly from Wuhan daily to destinations throughout the world. The timing also couldn’t have been worse. The virus coincided around the same time as Chinese New Year, a holiday that means massive travel (both domestic and international) for millions of Chinese, which helped spread the virus to multiple provinces across China, not to mention to multiple countries across the globe as well.
SARS ended up being contained before a vaccine was created. Although that doesn’t mean SARS vaccines weren’t created. Following the pandemic several different SARS vaccine trials were started but none went beyond clinical testing. But with how widespread COVID-19 had become, it became immediately clear the only way out of this new pandemic would be with a vaccine. And just as timing had played against us in the early days of COVID-19, this time in regards to the vaccine, it played in our favor.
Nearly twenty years has passed since SARS and medical technology has advanced by leaps and bounds since then. Back in 2004, the National Institute of Allergy and Infectious Diseases (NIAID) had begun work on a SARS vaccine that utilized a small ring of SARS DNA, a radical new vaccine methodology compared to the traditional vaccine which used a weakened or inactivated form of the whole virus. The then NIAID Director, Dr. Anthony Fauci was excited about the innovative prospects such a vaccine could offer. But mRNA and DNA vaccines seventeen years ago still faced quite a few obstacles. Early mRNA were hard to store and didn’t always produce the right type of immunity. DNA vaccines were more stable but weren’t efficient at getting into the cell’s nucleus, resulting in insufficient immunity. It was only by 2019 that academic labs and biotechnology companies had overcome the obstacle of vaccine stability and getting the genetic instructions where they needed to go and had dozens of promising mRNA and DNA vaccines for infectious diseases such as cancer, in phase 1 or phase 2 human clinical trials.
By the time COVID-19 struck, mRNA vaccines in particular were ready to be put to a real world test. Because mRNA vaccines only use a bit of genetic code from the pathogen, they are much faster to make. Once scientists get the genetic sequencing of a new pathogen, they can design a DNA or mRNA vaccine in days, identify a lead candidate for clinical trials within weeks and have millions of doses manufactured within months. Which is exactly what happened with the COVID-19 vaccine.
Many people misunderstood the quickness of the vaccine’s arrival and the mission name, ‘Operation Warp Speed’, given by the Departments of Health and Human Services and Defense to mean that corners had been cut. But in reality, mRNA vaccines have been the subject of careful study for over thirty years. It just so happened that when COVID-19 struck, time was on our side and the culmination of all those decades of research and testing was ready to be deployed.
The most important next step now is to ensure that as many people as possible can get vaccinated. Unlike SARS, COVID-19 has run wild long enough that variants have cropped up all across the globe, some more virulent and deadly than the original strain. Currently, the B.1.1.7 strain that was first discovered in the UK is now the most common strain in the U.S. A UK study found that B117 COVID-19 has a 64% higher risk for death for people older than thirty. Those diagnosed with this particular strain also have higher viral loads and are much more transmissible.
These variants can pose a danger to the effectiveness of the vaccine. In fact, they’re already posing a danger. The South African variant, B.1.351, is particularly virulent and much more easily transmissible. And recently, studies have been showing that this variant can “break through” the Pfizer and Moderna vaccine to some extent.
Countries all across the globe need to enact swift and comprehensive vaccine rollouts. In the U.S., nearly a quarter of the population has been fully vaccinated. In Britain, they’ve given the first shot to nearly half of its residents. In Israel over 80% of their population 70 and older had received both shots. But in some developed countries, they are lagging. Australia and South Korea have vaccinated less than 3% of their populations. Japan and New Zealand have vaccinated less than 1%. It’s surprisingly the countries who had an early grip on curbing the spread of the virus that are now dragging their feet with vaccinations. But with the Tokyo Olympics coming up and the rest of the world reopening, it’s important that all countries quickly vaccinate not just for the health of their citizens but for the health and safety of everybody.
So now, after the world has experienced both the SARS epidemic and the COVID-19 pandemic, do we now know enough to prevent against all future pandemics?
Researchers probably can’t guarantee against all but they do think they can possibly guarantee against one type of pandemic: the zoonotic pandemics. 75% of newly emerging diseases currently affecting humans are zoonotic, meaning they originated in animals, like SARS and COVID-19 did. Also how MERS emerged from camels.
We need to implement policies and systems to provide early warnings when a possible zoonotic infection is on the rise. Studies have shown that preventing disease spillover from wildlife costs 100 times less than trying to respond to such a disease once it has spread. And all of us who have experienced the last twelve months of this pandemic can attest to the economic devastation COVID-19 has brought across the world. Surveillance and early warning systems coupled with pandemic prevention planning can help deter any future zoonotic outbreaks, saving countless lives and livelihoods. And in an interconnected world that only grows tighter and closer with every passing year, information on any swiftly moving zoonotic virus needs to be shared and closely monitored by the global community. SARS and COVID-19 both reached both far and wide, and countries only benefited once they started working together to stop the spread. Prevention must also be worked on with the same allied mentality.
COVID-19 has taken over a year of our lives with most of us probably losing a total of two while we combat this pervasive virus. But we can learn from this experience and ensure that neither we nor future generations have to endure a similar hardship again. With medical science roaring forward in huge leaps and bounds, we can take even greater preventative measures to protect ourselves from experiencing another zoonotic pandemic ever again.