Why Are Novel Viruses a Big Deal?

New Viruses Are an Old Story

Viruses have shaped human history since before we knew what they were. And it’s not just the same old foes. Novel, or new, viruses emerge quite often. Since the year 2000, we’ve seen coronavirus outbreaks, deadlier strains of the flu, mosquito-borne Zika, and more. Even viruses that are familiar today were once novel. Like measles, which first appeared around the 9th century.

Each novel virus is different from all the known viruses that infect people. Some novel viruses cause small local outbreaks. Others grow into region-wide epidemics or even global pandemics.

We can’t know when or where a novel virus will emerge, but history tells us it will happen. And novel viruses are everyone’s problem. Individuals, public health officials, healthcare workers, and scientists all face challenges as we work to keep new viruses under control.

Where do novel viruses come from? To find out, visit When Viruses Jump Hosts.

Novel Viruses Are a Big Deal From Many Perspectives

People Are Not Immune

If a novel virus spreads well between people, nearly everyone exposed could get sick. We saw this in 2020 when SARS-CoV-2 emerged, spread, and grew into a pandemic. One reason the virus spread so quickly was that no one had immunity yet. Immunity means your body resists infection. You get immunity either from a vaccine or from having had the virus before. When a novel virus first appears, there is no vaccine and hardly anyone has been infected. That means the only ways to slow its spread are public health measures like hand washing, wearing masks, and physical distancing.

Immunity is specific. Your body remembers a virus it has had before and stops it quickly. But your body can’t remember something it’s never been exposed to. So prior infection with one virus doesn’t keep you from being infected by a novel one. For example, having a cold won’t protect you from getting the flu (or vice versa). Even though some cold and flu symptoms are the same, they’re caused by two very different viruses.

Public Health Workers Must Catch Up With Early, Undetected Spread

Before public health officials can stop an outbreak, they must first recognize that one is happening. It’s not as simple as it sounds. Novel viruses tend to share symptoms with familiar ones. It can take many cases for an outbreak to be detected against the background noise of “normal” illnesses.

The first clue is usually when doctors notice and report unusual patterns to public health officials. For example, they may see patients whose symptoms look like a known illness, but it’s the wrong time of year. Or a patient’s symptoms may change or get worse with time. Enough unusual cases suggest something is going on. Like in 2003, when health officials started getting reports of “atypical severe pneumonia” in China. These turned out to be some of the first cases of the novel coronavirus SARS.

At the start of a new outbreak, public health experts need to answer some key questions. Where and how did the outbreak begin? What is the cause? How does the virus spread? The answers can help focus efforts to stop the virus.

Once we spot a new outbreak, the next steps are to find the cause and learn how it spreads. Viruses spread differently, so it takes different public health measures to control them. Most early control measures focus on efforts that work well for almost every virus, like hand washing, contact tracing, and confining people who are sick.

As we learn more about the novel virus, experts can recommend control measures that are more specific. Like wearing masks for a virus that spreads through droplets we breathe out. Or safer sex for one that spreads through sexual contact. Clear and consistent guidance is important so people know how to protect themselves.

The faster we learn about a virus, the sooner we can stop it. Until an outbreak is recognized and the cause found, a novel virus can spread silently. If silent spread goes on for too long, or if the outbreak reaches an urban center, the virus is much harder to control. This happened in 2014, when Ebola spread unrecognized for months in West Africa. Before we knew it, the virus reached large cities and grew into an epidemic. It’s likely Zika spread for about a year before it was detected. And H1N1 (the virus that caused the 2009 swine flu pandemic) was so fast it spread around the globe within nine weeks.

Healthcare Systems Are Flooded With Patients

When a novel virus spreads fast and undetected, large numbers of people can get sick with little warning. If the illness is bad enough, many infected people go to clinics and hospitals.

This surge of patients can overwhelm healthcare systems. During the swine flu pandemic, US hospitals saw visits to emergency rooms go up by about 18 percent. At some hospitals, it went up even more.

Balancing resources is an important job for healthcare systems in normal times. But it’s even more important when there’s a sudden increase in patients. Hospitals need to manage the number of beds, supplies and equipment for treating patients, staffing, and more. This gets harder when healthcare systems are already stretched to their limits.

Emergency rooms, often crowded during normal times, are stressed even more by a novel virus.

Resources are still needed for regular healthcare too. After all, other illnesses don’t stop just because there’s a new virus around. Hospitals and clinics must maintain other types of care while working to prevent the spread of the virus within their walls.

To prepare for outbreaks, most hospitals have at least one full-time emergency manager and a pandemic preparedness committee. These experts plan for as many scenarios as they can, but every outbreak brings many unknowns. Depending on the virus, caregivers may need different equipment to prevent its spread and to treat patients. Hospitals and public health systems can do a lot to prepare. But it isn’t possible to stockpile enough equipment and medication for every possible scenario.

Careful planning and management are necessary, but they aren’t always enough. Early in the COVID-19 pandemic, there was a worldwide shortage of the personal protective equipment that healthcare workers use to protect themselves and their patients from infection. Lack of supplies like gloves, masks, and hand sanitizer put the people who cared for patients at risk for infection. This strained the workforce even more.

Drive-up testing during the COVID-19 pandemic kept people with mild symptoms out of clinics where they could spread the infection.

It takes time and careful study to develop effective vaccines and treatments for novel viruses.

Experts Need Time to Develop Vaccines and Treatments

Our best chance of stopping a new outbreak from growing into an epidemic (or worse) is with a quick response. But this is a huge challenge. Medical interventions—like tests, vaccines, and drugs—take time to develop. They need to be specific to each virus. They need to go through extensive testing to make sure they’re safe and they work.

Sometimes scientists can use what they know about related viruses to get a head start. For example, H1N1 is related to the virus that causes seasonal flu. Scientists could use what they knew about making seasonal flu vaccines to make one specific for H1N1. And during the 2020 COVID-19 pandemic, vaccine developers drew from methods that worked against other viruses.

In the meantime, doctors figure out new ways to care for patients. Their ideas sometimes go on to change medical care. For example, the “artificial lung” wasn’t used outside of surgery until the Polio epidemic in the 1950s. When doctors tried it, the survival rate for patients with breathing problems went from 13 to 69 percent. And because small groups of doctors specialized in treating the sickest patients, it led to the first intensive care units.

What Can We Do to Prepare?

Viral outbreaks are complex events. They’re complex in how they start and how they spread. And they have complex effects, which can be medical, social, psychological, and economic.

By being ready, we can manage some of the effects. While novel viruses are a fact of life, predicting outbreaks and catching them early goes a long way toward stopping them. When we detect a new outbreak, public health measures like surveillance, testing, and isolating cases can buy time while treatments and vaccines are developed. Then, we can use all our tools together for a better outcome.


Falcone, R. E., & Detty, A. (2015). The Next Pandemic: Hospital Management. Emergency Medicine Reports, 36(26).

Faria, N. R., Quick, J., Claro, I. M., Thézé, J., de Jesus, J. G., Giovanetti, M., Kraemer, M., Hill, S. C., Black, A., da Costa, A. C., Franco, L. C., Silva, S. P., Wu, C. H., Raghwani, J., Cauchemez, S., du Plessis, L., Verotti, M. P., de Oliveira, W. K., Carmo, E. H., Coelho, G. E., … Pybus, O. G. (2017). Establishment and cryptic transmission of Zika virus in Brazil and the Americas. Nature, 546(7658), 406–410.

Grubaugh, N. D., Ladner, J. T., Lemey, P., Pybus, O. G., Rambaut, A., Holmes, E. C., & Andersen, K. G. (2019). Tracking virus outbreaks in the twenty-first century. Nature microbiology, 4(1), 10-19.

Heymann, D. L., & Rodier, G. (2004). Global surveillance, national surveillance, and SARS. Emerging infectious diseases, 10(2), 173–175.

Holmes, E. C., Rambaut, A., & Andersen, K. G. (2018). Pandemics: spend on surveillance, not prediction. Nature, 558(7709), 180–182.

Morefield G. L. (2011). A rational, systematic approach for the development of vaccine formulations. The AAPS journal, 13(2), 191–200.

Oppenheim, B., Gallivan, M., Madhav, N. K., Brown, N., Serhiyenko, V., Wolfe, N. D., & Ayscue, P. (2019). Assessing global preparedness for the next pandemic: development and application of an Epidemic Preparedness Index. BMJ global health, 4(1).

Rambaut, A., & Holmes, E. (2009). The early molecular epidemiology of the swine-origin A/H1N1 human influenza pandemic. PLoS currents, 1, RRN1003.

Ranney, M. L., Griffeth, V., & Jha, A. K. (2020). Critical supply shortages—the need for ventilators and personal protective equipment during the Covid-19 pandemic. New England Journal of Medicine, 382(18), e41.

Rubinson, L., Mutter, R., Viboud, C., Hupert, N., Uyeki, T., Creanga, A., Finelli, L., Iwashyna, T. J., Carr, B., Merchant, R., Katikineni, D., Vaughn, F., Clancy, C., & Lurie, N. (2013). Impact of the fall 2009 influenza A(H1N1)pdm09 pandemic on US hospitals. Medical care, 51(3), 259–265.

Woolhouse, M., Scott, F., Hudson, Z., Howey, R., & Chase-Topping, M. (2012). Human viruses: discovery and emergence. Philosophical transactions of the Royal Society of London. Series B, Biological sciences, 367(1604), 2864–2871.

Woolley, K., Smith, R., & Arumugam, S. (2020). Personal Protective Equipment (PPE) Guidelines, adaptations and lessons during the COVID-19 pandemic. Ethics, medicine, and public health, 14, 100546.

World Health Organization. (2014). Ground zero in Guinea: the Ebola outbreak smoulders–undetected–for more than 3 months.

Wunsch, H. (2020). The outbreak that invented intensive care. Nature.