FEW CASES FOUND AMONG VACCINATED
County also sees significant increase in supply of doses
On a day when California found itself with the lowest coronavirus case rates in the continental United States, San Diego County received a little extra good news Wednesday: The local vaccine supply increased significantly this week, and the number of fully vaccinated people who are still becoming infected has been small.
Dr. Eric McDonald, medical director of the county epidemiology department, said during a weekly coronavirus briefing that, as of Tuesday, 203 local residents among the 846,886 who are fully immunized have tested positive for COV2 infection.
That denominator includes only those who are at least two weeks beyond their final dose.
“We’ve had zero people who have been hospitalized, zero people who have died. In fact, the majority — 57 percent — have had no symptoms at all,” McDonald said. “These are people who were fully vaccinated and were tested for other reasons, because they were in health care, for example.”
That’s a post-vaccination infection rate of about .024 percent in San Diego County.
However, real-world studies have estimated that coronavirus vaccines are about 90 percent effective at generating a strongenough immune system response to fight off infection. That means that 10 percent of those who are now fully vaccinated — about 84,000 people in San Diego County — could become infected if they were exposed to the virus. About 1.7 percent of tests have been coming back positive in the last two weeks, suggesting that there are likely significantly more than 203 people who have been infected after becoming fully vaccinated. That’s good news because their illness was not severe enough to seek medical attention.
While San Diego’s number is small, it is nonetheless about three times greater than the national rate, McDonald said. According to a report published Friday by the U.S. Centers for Disease Control and Prevention, there have been 5,816 confirmed COV2 infections among the 75 million Americans so far fully vaccinated for a rate of about .008 percent
The public health world calls these folks — those who still get sick after full vaccination — “breakthrough” cases because their immune systems did not generate a significant enough response to keep the target pathogen at bay.
McDonald was unconcerned that the tiny breakthrough rate detected so far in San Diego County is greater than the national rate. He put the difference down to the fact that local jurisdictions get data more quickly, so San Diego’s counts are simply more up-to-date.
No one, he said, should be surprised that some people still become infected after inoculation. While recent efficacy studies found that the Moderna and Pfizer vaccines are 90 percent effective two weeks after a second dose, that leaves 10 percent without full protection.
“We expect to see those numbers, they are very, very low and emphasize how good, frankly, the vaccine works,” McDonald said.
While the county seems to have escaped severe illnesses among local breakthrough cases, that has not been the case nationwide. The CDC report found that 396 or 7 percent of breakthrough cases were hospitalized and 74 or 12 percent of those died, though some of those were for reasons not thought to be directly related to the disease.
The county also announced Wednesday that the state has allocated 294,440 vaccine doses to providers across the region this week, a number that is nearly 100,000 more than were made available last week and the most given in a single week since March 1. It was not clear whether this week’s allocation is a single-week record since vaccination started in mid-December.
Nathan Fletcher, chair of the county Board of Supervisors, said this week’s allocation may or may not be the start of a trend.
“We don’t yet know what next week will look like, but this is encouraging,” Fletcher said.
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.