Virulence can be described as the harm caused by a pathogen onto its host following an infectious event. It’s a relative term, and could measure anything from specific symptoms a pathogen causes, to overall host fitness. In short, virulence measures the severity of disease a pathogen causes.

Let’s think back to the start of the pandemic, in late 2019. Our first introduction to the virus was HIGHLY virulent and caused an array of severe symptoms in their hosts; often resulting in long term detrimental health effects, frequently to the point of death. We had seen outbreaks of coronaviruses in the past, however none were as virulent as we were witnessing with SARS-CoV-2.

This led to scientists speculating about the source of COVID’s virulence. Although we are still learning about the virus, many different virulence factors about SARS-CoV-2 have been proposed, including: Structures of spike proteins that help the virus bind to host immune cells, unique FURIN cleavage sites, mechanisms that allow the virus to manipulate host immune cells, so-on and so-forth. 

There have been many variants of SARS-CoV-2 that have emerged since the outbreak began in late 2019. Starting with alpha, onto the dominant strain as of writing this post; omicron. Each one seemingly different than the next. The 5 main pandemic strains of concern are as follows:

Based on the characteristics of the above variants, can we say that the virulence of SARS-CoV-2 has changed overtime? I would say yes. We can definitely see a pattern of virulent factors developing in the virus overtime. However, in a clinical sense, one could argue that the virus is evolving to become LESS virulent. Clinicians could tell you how they are seeing less severe COVID cases during omicron, fewer patients dying of the disease than at previous points in the pandemic. Concurrently, we also see the virus become MORE transmissible over time, with human-to-human spread increasing due to the variant. 

Could this be the evolutionary strategy taking place? As time goes on, we are seeing COVID-19 transform into a community disease; meaning, it is present in the population for the long-term. Could an evolution towards low virulence, high transmissibility be the best strategy for the virus itself to achieve the highest fitness? Get the host sick enough that they are shedding the virus, but not sick to the point that they are incapacitated/dead? 

It’s now been over a year since Omiron was first identified, and it is STILL the dominant strain of SARS-CoV-2 in our population. Perhaps the virus is getting closer to finding its “happy medium”. After all, as we’ve learned in class, the dominant hypothesis is that intermediate virulence will always be preferred in the virulence/transmission trade-off… I guess only time will tell.

Let's review how the US fared in each of these categories.

Monitoring

According to the CDC, epidemiologists monitored the pandemic in various ways, including: Incidences of new case reporting's, prevalence of cases based on location, number of cases resulting in hospitalizations, and lastly, deaths. 
Looking back, a few issues were presented here. Firstly, although a public test for COVID-19 was created on January 28th of 2020, there were restrictions on who could receive them. It wasn't until a few months later that these restrictions were relaxed. Even then, the government couldn't supply the amount of tests that were needed.

Although access to testing got better over time, throughout the duration of the pandemic, the US never reached the recommended threshold for controlling an outbreak according to the World Health Organization.

Public Education

Since so little was known about the virus, initial education to the public was all over the place. Looking back, the US government really mishandled how they rolled out information to the public. The information we were being presented was all over the place, to the point that even our public health leaders seemed to be confused.

Untrustworthy information from our government, coupled with a large population of under-educated individuals as a result of our under-funded education systems, created, in my opinion, the worst-case scenario of how a population could deal with a pandemic.

Crowd Control

Unfortunately, crowd control did not necessarily occur in the US. Other countries quickly implemented strict lockdowns and travel bans once they got word of the outbreak; we did not. The federal government basically left it up to the states on how they wanted to handle this: What jobs were essential, what public spaces could stay open, how many people could gather at a time. Unfortunately, not much was done regarding this matter, and if it was, much of the public chose not to follow.

Care Facilities Management

Our system simply wasn't ready to handle a pandemic of this magnitude. A public messaging of "flatten the curve" began to spread. Throughout the length of the pandemic, many major hospitals became overwhelmed. ICU's filled up with patients needing ventilators. COVID was a priority, and hospital beds quickly filled; leaving those that needed hospitalization for other reasons out-of-luck. Many COVID patients needed ventilators; there weren't enough. ICU's needed more nurses; there weren't enough. Hospital workers needed proper PPE in order to not get exposed to the virus themselves; there wasn't enough. In the hardest hit metro areas, the US military had to set up emergency triage centers to deal with the overwhelming number of cases. One can only assume that the lack of proper care facilities in the US contributed to our high pandemic death toll.


    Although our public health/medical systems were not ready to handle the outbreak of the SARS-CoV-2 virus, our scientific communities were about to do something astounding; rapidly create mRNA vaccine for COVID-19; that has proven to be safe and effective years after it’s release. Roughly a year into the pandemic, the FDA was able to grant emergency access to mRNA vaccines being made available to the most at-risk public. Unlike a traditional vaccine that uses whole weakened/dead viruses to trigger our adaptive immune response, an mRNA vaccine only administers genetic material; the code for the surface binding proteins your immune system will need to detect the virus. Other types of vaccine were also developed, including protein-subunit  vaccines (which administer only the protein subunits), and viral vector (which uses another virus modified as a viral vector).

Also, there are now treatments available to the public for the treatment of COVID-19. These include antiviral drugs that prevent the virus from multiplying after infection.  Veklury is administered in hospital settings. Paxlovid and Lagevrio can be taken at home. Convalescent Plasma Therapy (blood transfusion from recovered individuals) is also an approved and effective treatment for COVID-19 per the CDC.

At first, it seemed as though the government was banking on this pandemic being a 2-week stint. Instead, deaths ramped up and our economy began showing signs of downturn. Quickly, it became apparent that our government needed to step in and intervene, and deal with the new hardships Americans were facing during this unprecedented pandemic.

In March of 2020, roughly 4 months into the pandemic, Congress came up with their plan. It would come in 3 parts:

Although that all looks great on paper, the reality was more complicated.

Some of the things in these government acts were great. Science NEEDED funding to study the virus and come up with a vaccine; one year later the American public were able to choose from multiple safe, free, and effective vaccines for COVID-19. Rental protections helped paycheck-to-paycheck prevented families from being evicted when faced with pandemic job insecurities. Food-stamp benefits were increased for low-income families; many of whom rely on public schools to provide their children with meals for the day (which were now shut down). 

Some things didn’t go as planned. Using the concept of universal basic income, stimulus checks for the American people were proposed to stimulate the economy. However, recurring payments turned into one… What was supposed to be a $2000 check became less… You only received them if you yourself had filed taxes in the previous year… In the end, the program became a drop in the bucket. Barely any money made it to the hands of the American people, and instead an increased amount of taxpayer money was given to corporations (shocker). 

Unfortunately, many Americans felt like their leadership failed them when it came to stopping the spread of the pandemic. Our own President at the time chose to downplay the severity of the pandemic. While our congress was putting together the initial covid relief packages, our President was nowhere to be found. Instead, he was busy going around the country, pushing his narrative of 2020 election fraud. Public health officials were unclear when giving information to the public, leading many to distrust anything they were saying; and instead turned to (unreliable) sources of their choosing. 

In the end, as of writing this post, 1,129,573 Americans have died from the virus. Was this death count inevitable? Or could stronger leadership in the early days of the outbreak have prevented such national tragedy? It’s up for discussion.