Faced with a resurgence of COVID-positive patients — and a stubborn aversion to vaccines among many Miami-Dade residents and even its own employees — Jackson Health System, the county’s public hospital, issued a single-minded message on Tuesday: Get vaccinated.

On Tuesday, 143 COVID-positive patients were admitted to Jackson Health, a 117 percent increase from the 66 patients admitted just two weeks ago.

According to Dr. Lilian Abbo, an infectious disease specialist at Jackson Health, 91% of COVID-positive patients are not vaccinated. She claims that in intensive care units, 95 percent of patients who are critically ill with the disease have not received a shot.

Abbo attributed the increase in new infections and hospitalizations to behavioral changes — “people behaving as if the pandemic is over,” she said. She also mentioned that the delta variant, a highly transmissible mutation of the virus that causes COVID-19, as well as so-called breakthrough cases among vaccinated people, are contributing to the rise.

According to the Centers for Disease Control and Prevention, the delta variant has become the dominant strain in the United States, accounting for 83 percent of all new infections in the two weeks ending July 17, the agency said Tuesday. During the same time period, the delta variant accounted for roughly 80% of all new infections in the Southeast, which includes Florida.

Jackson Health is not sequencing viruses to identify the strain causing the increase in COVID patient admissions, but Migoya believes “the delta variant has a lot to do with this.”

According to Abbo, the delta variant is not only more transmissible, but it also has a shorter incubation period and a higher viral load, which means that those who are infected shed more of the virus that causes COVID-19 and risk infecting others — whether they are vaccinated or not. Though Jackson Health officials are concerned about the sudden increase in cases and hospitalizations, Migoya says the current wave is “nowhere close” to the flood of COVID-positive patients that nearly overwhelmed the county’s public hospital last summer.

But, in order to avoid a repeat, Jackson Health has suspended visits at most of its facilities beginning Wednesday and has reinstated preventive measures such as social distancing and universal masking in all non-clinical areas.

The most effective tool for halting the surge, according to Migoya, is one that many in Miami-Dade and even within Jackson Health have refused to use — one of three vaccines approved by the Food and Drug Administration for emergency use, which have become widely available since the first shots were approved in December

According to the Florida health department’s weekly COVID report, more than 1.8 million Miami-Dade residents — or roughly 75% of eligible individuals — had received at least one dose of the vaccine as of July 15. While one-quarter of eligible residents may not appear to be a large number of unvaccinated people, Migoya emphasized that this equates to approximately 500,000 people.

The vaccination rate among Jackson Health’s nearly 13,000 employees is lower than that of Miami-Dade. Migoya stated that approximately 58 percent of Jackson Health employees have been vaccinated, a figure he admitted was “low.”

Migoya attributed the low rate to persistent vaccine rumors and misinformation.

According to Migoya, the current surge has persuaded some hesitant employees to take the job. Jackson Health administrators are working to get even more employees vaccinated by sending the same message to the community: the longer and more severe COVID surges become, the more people remain unvaccinated.

Abbo went on to say that even as breakthrough infections gain attention, vaccines continue to provide effective protection against severe disease and death. Doctors and nurses can tell the difference between today’s patients and those from a year ago.

In addition, unlike last year’s pandemic surge, when the majority of severely ill patients were older and had underlying health conditions, the most recent increase in hospitalizations includes many healthy patients in their 30s, 40s, and 50s.

Migoya explained that some of the newer COVID therapies developed since the pandemic began, such as monoclonal antibodies, are not appropriate for young and healthy patients because they are reserved for high-risk patients who are obese, pregnant, or have chronic kidney disease, diabetes, or other medical conditions.

That leaves prevention as the best medicine, and the most effective and safe way to stop COVID, according to him, is with a vaccine.