Florida boasts millions of international tourists and six cruise ship ports, including Port Canaveral. All those human movements and interactions increase opportunities for the virus to spread, infectious disease experts say.

With any novel coronavirus vaccine more than a year away, new cases and fears could mount, especially in Florida, where tourism, travel and age prime the Sunshine State for potential pandemics.


Florida boasts millions of international tourists and six cruise ship ports, including Port Canaveral. All those human movements and interactions increase opportunities for the virus to spread, infectious disease experts say. Add to that an aging population.


"I think the most worrisome part is the elderly population in Florida," said Dr. Yang Yang, an associate professor at University of Florida's department of biostatistics. Because of tourism, "We probably will see more imported cases," he predicted, which could increase the risk to the elderly.


One in 5 Floridians, and 1 in 4 Brevardians are over age 65, U.S. Census Bureau data shows. Do you know how many are 80 plus? I thought that was the big risk age?


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Yang and other health researchers say the new virus' spread in Florida will depend on daily choices: where we travel, whether and how we wash our hands, ride public transportation and interact with the healthcare system — all variables difficult to predict. Further complicating predictions is the coronavirus' lengthy incubation period.


COVID-19 stands for coronavirus disease 2019, caused by a virus named SARS-CoV-2. SARS is short for severe acute respiratory syndrome. The disease was first detected in December 2019 in Wuhan, Hubei Province, China. As of Friday, the new virus had infected 234 and killed14 people in the United States, all associatedwith a nursing home in Washington state. Globally, the case count tops 100,000, with more than 3,400 deaths.


Symptoms of COVID-19 include fever, cough and breathing trouble. Most people suffer mild symptoms. But some, usually those with other underlying medical complications, develop more severe symptoms, such as pneumonia, which can be fatal.


Experts warn that because so many people appear to be asymptomatic and therefore not included in the infection counts, the death rate is likely lower than reported. But so much still remains unknown.


On Thursday, Gov. Ron DeSantis announced Florida's fifth case of COVID-19, a Santa Rosa County man over age 70 who'd recently traveled internationally and who has a severe underlying health condition.


Earlier this week, Barry Inman, an epidemiologist with the Florida Department of Health in Brevard, said the fast spread of the new disease, coupled with a "very mobile" population that travels internationally, makes local cases inevitable. He said the state Department of Health monitored 25 people in Brevard who within the past two weeks had traveled to countries affected by the virus. Most flew in from China, but none were sick, Inman said.


"They stay at home, they don't go to work, they don't go to school," Inman said of those monitored by the health department.


Inman likened the county's preparation for the new virus to that of swine flu, suggesting its spread could prove similar in nature and the number infected. That virus first hit the United States in 2009, infecting thousands in Florida that year, including 5 people in Brevard, according to state epidemiology reports.


"It’s similar to that, and we didn’t have a vaccine for about six to seven months into that," Inman said from the county's Emergency Operations Center.


But Yang says this virus could be worse than swine flu.


"I'm not that optimistic, because this virus is different," Yang warned. "It has a longer incubation period. The incubation period of this virus can be as long as 20 or 21 days."


People in Washington state were also optimistic early on, Yang added.


As of Friday, Washington state had 74 confirmed cases and 13 deaths, according to John Hopkins University COVID-19 global tracking site.


Uncertain if warmer weather will help


Florida's rising heat and humidity tempers other viruses, like those that cause the flu, which become less prevalent in warm, humid months. In warmer climates, people also tend to spend less time indoors, where viruses spread more easily.


Read more: FSU exploring distance learning options in event of coronavirus-related shutdown of campus


But because the coronavirus is so new, scientists aren't sure how it will respond as Florida temperatures warm.


A ray of hope for Florida shines from the nations with warmer climates that had imported novel coronavirus cases, such as Thailand, Vietnam and Singapore. Thus far, they have been spared large COVID-19 outbreaks, Yang said, but he also said there are no scientific studies to prove warmer temperatures temper the new virus.


"It's really difficult to stop it at an early stage, because that requires a very active screening process," Yang said of of why China failed to contain the new virus.


Wuhan, China, the epicenter of the new coronavirus outbreak, is a large hub connecting all regions of China via rail and a major international airport. Availability of connecting flights, the timing of the outbreak during the Chinese (Lunar) New Year, and Wuhan's massive rail hub allowed the virus to spread throughout China, and eventually, the globe, scientists say.


Why does a vaccine take so long?


Dozens of studies are underway of drugs to stop the disease. But despite a fast-track approach for a vaccine, federal health officials have said any shots available to the general public are at least 18 months away, with uncertain prospects for success.


The road to US Food and Drug Administration approval of a vaccine is a long, arduous, expensive one, fraught with high risk and potentially low reward, infectious disease experts say. But three dozen drug companies are racing to create an effective antiviral against the novel coronavirus.


The most promising, experts say, is remdesivir, an antiviral developed by the pharmaceutical company Gilead. Nebraska Medical Center in Omaha is embarking on the first randomized, controlled clinical trial in the United States to evaluate the safety and efficacy of remdesivir in hospitalized adults diagnosed with COVID-19, patients from the Diamond Princess cruise ship who were quarantined at the Nebraska facility.


On Wednesday, one patient left the National Quarantine Unit on the UNMC/Nebraska Medical Center campus, and another was cleared to go, leaving only eight remaining of the original 15 Americans from the Diamond Princess cruise ship who were quarantined there.


Seven of those are in the National Quarantine Unit, and one was being treated in the Nebraska Biocontainment Unit.


The remdesivir trials will be conducted in up to 50 sites globally, including clinics in Texas, Maryland and Washington state. Trials of the drug are underway in China as well.


The drug was previously tested in humans with Ebola virus and showed promise in animal models for treating severe acute respiratory syndrome (SARS) and Middle East respiratory syndrome (MERS), according to the National Institutes of Health. Both of those are caused by other coronaviruses.


Read more: Florida ports brace for possible coronavirus disruption of business


"Although remdesivir has been administered to some patients with COVID-19, we do not have solid data to indicate it can improve clinical outcomes,"NIAID Director and U.S. Coronavirus Task Force member Dr. Anthony Fauci, recently said. "A randomized, placebo-controlled trial is the gold standard for determining if an experimental treatment can benefit patients."


People with confirmed infection but mild, cold-like symptoms or no apparent symptoms won't be included in the NIH study.


On Thursday, the U.S. Senate authorized $8.3 billion to test, treat, contain and develop a vaccine for the disease.


As science searches for a vaccine, the public needs to balance caution and calmness, Yang says.


"We still need to wait to see how this will evolve, and then take immediate actions based on what we experience," Yang said. "Personal hygiene is always a good precaution."


This story originally published to floridatoday.com, and was shared to other Florida newspapers in the new Gannett Media network.