On a day when California found itself with the lowest number of coronavirus cases in the continental United States, San Diego County received a little extra good news Wednesday: Local vaccine offerings have increased significantly this week and the number of fully vaccinated people still becoming infected has been small.
Dr. Eric McDonald, medical director of the county’s epidemiology department, said during a weekly coronavirus briefing that as of Tuesday, 203 local residents of the 846,886 who have been fully immunized have tested positive for COV2 infection.
That denominator only includes those who are at least two weeks after their last dose.
“We haven’t had people hospitalized, no people died. In fact, the majority – 57 percent – have had no symptoms at all, ”said McDonald. “These are people who have been fully vaccinated and tested for other reasons, such as being in health care.”
That is an infection rate after vaccination of about 0.024 percent in San Diego County.
However, real world studies have estimated that coronavirus vaccines are about 90 percent effective at generating a strong enough immune system response to fight infections. That means 10 percent of those now fully vaccinated – about 84,000 people in San Diego County – could become infected if exposed to the virus. About 1.7 percent of the tests came back positive in the past two weeks, suggesting that significantly more than 203 people were likely infected after being fully vaccinated. That’s good news, because their illness was not severe enough to require medical attention.
Although San Diego’s number is small, it is nonetheless about three times the national rate, McDonald said. According to a report published Friday by the U.S. Centers for Disease Control and Prevention, there are 5,816 confirmed COV2 infections among the 75 million Americans fully vaccinated so far at a rate of about 0.008 percent. .
The public health world calls these people – those who still get sick after full vaccination – “breakthrough cases” because their immune systems did not generate a sufficient response to keep the target pathogen at bay.
McDonald was not concerned that the small breakout rate observed so far in San Diego County is greater than the national rate. He attributed the difference to the fact that local jurisdictions receive data faster, so San Diego’s counts are just more current.
No one, he said, should be surprised that some people still get infected after inoculation. While recent efficacy studies have shown that the Moderna and Pfizer vaccines are 90 percent effective two weeks after a second dose, 10 percent remain without full protection.
“We expect to see those numbers, they are very, very low and highlight how well, frankly, the vaccine works,” McDonald said.
While San Diego County appears to have seen a total lack of serious illness in breakthrough local cases, it hasn’t been the case nationwide. The CDC report found that 396 or 7 percent of breakthrough cases were hospitalized and 74 or 12 percent of victims died, although some of those outcomes were for reasons not directly related to the disease.
The county also announced on Wednesday that the state has allocated 294,440 vaccine doses to suppliers across the region this week, a number nearly 100,000 more than made available last week and the highest number in one week since March 1. It was not clear if this week’s allotment is a one-week record since the vaccination began in mid-December.
Nathan Fletcher, chairman of the County Board of Supervisors, said this week’s allotment may or may not be the start of a trend.
“We don’t know yet what next week will look like, but this is encouraging,” said Fletcher.
The pace of the local pandemic continued its flat trajectory in Wednesday’s report with 263 new cases and 187 COVID-related hospitalizations reported Tuesday.
Often criticized recently for its relatively strict, level-based stance on reopening, California was at the bottom of the case rate list when the CDC updated the national numbers Wednesday, averaging 40.3 cases per 100,000 residents in the past seven days. Michigan tops the list at 483 per 100,000 with Florida at 201 and Texas at 65.9.