HOUSTON, Texas (KTRK) -- Men and women in bright yellow vests have begun going door-to-door at randomly selected Harris County homes.
But don't be alarmed. They are important to the fight against COVID-19.
Harris County Public Health kicked off its month-long survey this week to test blood samples for virus antibodies. The operation is expected to last through Dec. 15.
On Thursday, workers set up base at George Bush Park in west Harris County before crews embarked on nearby neighborhoods.
HCPH wants to sign up 420 households for the voluntary study. Up to four members of each home will be asked for a blood sample at no cost to them.
PREVIOUS STORY: Harris Co. preparing to test random residents for COVID-19 antibodies
Residents can be assured that the workers are taking precautions when visiting homes.
"Our field teams are wearing PPE. They are wearing face masks. And those individuals collecting blood will also be wearing gloves. In addition to that, our field teams will not be entering the households. They will only be completing the survey and the blood draw outside of the participant's home," said Deobrah Bujnowski, the principal investigator at HCPH.
Research done early in the pandemic by the Centers for Disease Control and Prevention showed about 40% of people who had the coronavirus were asymptomatic. According to HCPH, the basis of the study is to understand how vulnerable the community remains to the virus, and how frequently asymptomatic or mild cases occur. The results will also help policy makers in future decision making, which includes things like the county's COVID-19 threat level.
The key takeaway, though, is that if a person had the virus and didn't realize it, that person could have unknowingly spread it.
In terms of whether you should get an antibody test on your own, one UTHealth infectious disease specialist said there's still much uncertainty about COVID-19's long-term effects.
"We're barely starting to learn what antibodies mean, whether they're protective or not," said Dr. Luis Ostrosky of UTHealth. "(The antibody test) is a tool to understand the risk a little bit better and to know what happened to you. But by no means is this a passport to, say, go out and party without a mask."
In short, antibodies are not a "passport" of immunity, Ostrosky summarized, because they don't guarantee immunity to the virus.
As for the survey, HCPH says its outreach teams will be at various county areas from each day from 8 a.m. to 5 p.m. They will be identifiable with yellow vests and workers will be carrying identification cards.
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