How close are we to herd immunity? The data is clear enough

More than half of Texans have either recovered from the coronavirus or have been fully vaccinated as of Monday, according to state data.

When 75% or so of us have immunity, we will have reached what is sometimes called “herd immunity,” when the virus can hardly spread even in the absence of safety precautions like physical distancing and masks.

Herd immunity is a “calculated number based on the infectivity of a virus,” explained Baylor College of Medicine President Dr. Paul Klotman.

For example, herd immunity for the highly contagious measles virus is 95%. For regular COVID-19, it’s closer to 65%.

The more infectious variants make true herd immunity for this pandemic about 75%, Klotman said.

“I think we’re getting close,” he added, pointing to local data.

More than half a million people in the nine-county Greater Houston area have contracted COVID-19 officially, as of Monday.

The true number is closer to 2.4 million, based on numerous “prevalence” studies, including a CDC study, showing that for every positive COVID-19, there are several others uncounted.

About 1.5 million people in the region have been fully vaccinated. Together, that’s about 3.8 million people out of the 7.2 million who live in Greater Houston, or about 52%.

“They’ll be some overlap” in the numbers, Klotman said.

The data is approximate, but it also mirrors state data.

Out of 29 million Texas, nearly six million have been fully vaccinated as of Monday and about 11 million have contracted the virus (officially, 2.5 million have tested positive).

That’s nearly 17 million Texans with immunity or about 57%. When we get to about 22 million recovered or vaccinated, we will have reached “herd immunity.”

The number of Texans vaccinated every week is increasing rapidly, and Dr. Klotman said we are on track to reach that high level of immunity by late June.

“We’re getting there,” Dr. Klotman said. “About two months.”

When asked on Fox News Sunday if he thought Texas had reached herd immunity, Gov. Greg Abbott said:

“When you look at the senior population, for example, more than 70% of our seniors have received a vaccine shot. More than 50% of those who are 50-65 have received a vaccine shot.”

“I don’t know what herd immunity is,” the governor added. “but when you add that to the people who have acquired immunity it looks like you could be very close to herd immunity.”