With 1.4 million confirmed infections about 0.4% of the United States has had a known infection. But we know testing is inadequate given that there is such a high positive test rate (14% of all tests so far are positive). So we know the real rate of infection is higher than that.
The group that did the Santa Clara antibody test have run another test on 5,600 baseball employees and this time found only 0.7% carry the antibodies. The researchers were surprised.
About the only message we can really draw from this is the US is a long way from Herd Immunity, and as the US reopens there are twenty to fifty times as many people who could still catch this.
LA Times: Fewer than 1% of MLB employees test positive for COVID-19 antibodies
Of the 5,603 major league employees who submitted to what researchers called the largest national antibody study to date, only 60 tested positive, researchers said Sunday.
The researchers announced an estimated positive rate of 0.72% after adjusting the results for what they said were false positives and false negatives.
Still, the minute percentage of positive tests provided a data point as scientists determine how wide the coronavirus has spread within the United States. Bhattacharya said he expected a larger positive rate.
“The epidemic has not gotten very far,” he said. “We have quite a way to go.”
There are many caveats. This test is still not random, nor as Steve Sailer notes, does it appear to be published (can anyone find it?). The adjustments are still large. The Santa Clara test found 1.5% of those who answered an advertisement carried antibodies to Covid-19 in that high risk county. The authors corrected for postcodes but not age, and estimated that was really 3 -4%. Here, perhaps responding to the criticisms of their first study, they adjusted the 1.1% result down to compensate for the false positive rate.
Most of the antibody studies struggle with randomizing their data, and selection bias. They often draw on higher risk groups like pregnant women, homeless people, or attract in the high risk people in high risk areas. This study had more white men aged under 65.
Ultimately antibody tests may not be much use as long as the infection rate is so low it in the same range as the false positives (around 0.5%). It’s some use to public health officials, but not to the people who got tested. Around half the positive tests may be false — which is not much help to employers or employees looking to get people back to work. They only have a 50:50 chance the test is right.
But the message is that even if as many as 2% of the US population had been exposed to Coronavirus, 98% haven’t been.
The lack of any closed borders or mass mask wearing has cost the US dearly.
Things worth knowing about Coronavirus:
- Quarantines work: 12 days after lockdowns, quarantines and isolation, Coronavirus slows. This is text book microbiology.
- The stroke virus? Covid causes hundreds of microclots throughout the lungs (and everywhere else)
- Coronavirus causes clotting: hold the ventilators, stop blood clots instead
- Coronavirus can affect brains, may increase stroke risk.
- Solve Vitamin D deficiency first to help beat Coronavirus.
- New York is “like mass casualty event”: coronavirus and other deaths are up three-fold
- Coronavirus may be man made. Why did the CCP destroy the evidence?
- Looks like we can extinguish Coronavirus: Australia and NZ tracking to zero.
- Large coronavirus random tests in Austria show only 1% infected
- Read Crush the Curve — save the economy