"Severe" is the highest level and calls for unvaccinated people to stay home unless they need to leave for an essential reason such as going to the grocery store.
According to the threat level system, "severe" is enacted when there is a severe and uncontrolled level of COVID-19, outbreaks are present and worsening and testing and contact tracing capacity is strained or exceeded.
Some hospital emergency rooms are indeed operating at full capacity amid the surgent and rampant spread of the highly transmissible delta variant.
Houston Methodist said its ER volume is a combination of severely ill patients flooding their ER amid a surge of COVID-19 cases.
"We are seeing an increase in COVID numbers, probably more so than we have this whole entire pandemic," said ER nurse manager Danielle Butler-Winey. "It is unvaccinated people coming in with COVID."
These are the four levels of the COVID-19 threat system for Harris County:
- Level 1 - Severe (red) Stay Home
- Level 2 - Significant (orange) Minimize All Contacts
- Level 3 - Moderate (yellow) Stay Vigilant
- Level 4 - Minimal (green) Resume Normal Contacts
Hidalgo was joined by Houston Mayor Sylvester Turner and local health experts, including Dr. David Persse, Chief Medical Officer for the City of Houston.
Persse pulled no punches Wednesday during another press conference about the severity of the disease and the need to get vaccinated.
"We're seeing a huge increase in the viral activity in the community to the point where if you're currently unvaccinated, you need to consider that you represent a potential danger to yourself and others, and most particularly your own family, because we have found that those who get infected are most often infected by another family member," Persse said.
Time is of the essence for another reason, experts say.
Dr. Anthony Fauci, the nation's leading infectious disease expert, has warned that if more Americans don't get vaccinated, there is "ample chance" of another coronavirus variant emerging, one that could be more aggressive and more pervasive than the delta variant.
"If another one comes along that has an equally high capability of transmitting but also is much more severe, then we really could be in trouble," Fauci said.
On Wednesday, Texas health officials said the increasing rates of new COVID-19 cases, hospitalizations and deaths in Texas are showing steeper jumps than past surges.
In a video conference, Chris Van Deusen, the Texas Department of State Health Services spokesman, said the rolling seven-day average of new COVID-19 cases has soared by 92% from last week, while hospitalizations rose by 49% and fatalities grew by 15%.
The increase was blamed on the highly contagious delta variant, which can even be spread by those fully vaccinated against the coronavirus, said Dr. Jennifer Shuford, the state epidemiologist.
The U.S. Centers for Disease Control and Prevention estimates that more than 80% of all new COVID-19 cases involve the delta variant. "And our preliminary data suggests that over 75% of COVID-19 cases in Texas are now due to the delta variant," Shuford said.
She added that the rise in new cases "is similar to what we've seen in previous waves and might even be steeper. And that really shows how contagious the delta variant is. It's spreading much more rapidly among unvaccinated people than the viruses that we saw last year."
In the face of such grim statistics, Van Deusen said the rolling seven-day average of vaccinations has also climbed about 75% in the past month, from about 44,000 a day on July 4 to about 75,000 per day as of Tuesday.
"It really seems that people are getting the message that this is a serious situation. If they have been putting off getting vaccinated, now's the time to stop. Don't put it off any longer," he said.
However, CDC data show just 44% of the state's population was fully vaccinated, meaning both doses of the Pfizer and Moderna vaccines or the single dose of the Johnson & Johnson vaccine.
"It's simple. Over 2.5 billion people on the planet have been vaccinated. If there was a problem with the vaccine, we would know it by now. So for those folks who say, 'Wow, I'm not so sure. I'm a little afraid. I don't know what you're afraid of," Persse said Wednesday. "We are detecting problems, the rare problems to the point, if a problem occurs, one in a million times, we know about it. That's the level of scrutiny that this vaccine has gone under. Far more scrutiny than any vaccine in history. It is a safe vaccine, it is an effective vaccine. And we need people to get vaccinated because our momentum is going in the wrong direction."
"Breakthrough cases" among those who have been fully vaccinated are inevitable, especially among those without strong immune responses, Shuford said. "We know that no vaccine is perfect. They never will be."
But those vaccinated people who do get sick with COVID-19 are likely to have a shorter, milder illness. "And fully vaccinated people are very well protected from severe illness and death from COVID-19, even from the delta variant," Shuford said.
She also emphasized the importance of following recently updated CDC guidelines on masking and social distancing in indoor public settings, especially children aged 2-12 who are not yet eligible to receive the vaccine.
The Associated Press contributed to this report.