Breakthrough cases are 0.2% of fully vaccinated

Unvaccinated residents were 89.4% of Tuolumne County’s new COVID-19 cases, 86.8% of hospitalizations and 100% of deaths from May 24 through Wednesday, while only 0.2% of fully vaccinated residents have tested positive over the same period.

The percentages come from an analysis of data on cases provided each day by the county Public Health Department, as well as vaccination data reported by the U.S. Centers for Disease Control and Prevention.

“The numbers speak for themselves in that it really is a reduction in disease,” Dr. Eric Sergienko, the county’s interim health officer.

There were 449 cases in the county from May 24 through Wednesday, not including inmate cases at Sierra Conservation Center state prison near Jamestown. Of those, 401 were unvaccinated people and 48 were vaccinated.

A total of 38 hospitalizations were reported by the county over the same period, with 33 being people who were unvaccinated and five being people who were fully vaccinated. The unvaccinated total included one person who had to be hospitalized twice.

Two deaths occurred during that period, a man in his 80s and another in his 70s, both of whom were unvaccinated and died after being hospitalized for the coronavirus. There were also four late-reported deaths that occurred earlier in April and May, all of whom were unvaccinated.

May 24 is significant, because that’s the date when the county began reporting the vaccination status of new cases. The first known breakthrough case of a fully vaccinated county resident testing positive was on June 17.

The percentages fall closely in line with earlier projections that the available vaccines are as much as 88% effective at preventing infection against the highly contagious delta variant, now the dominant strain throughout California and the United States.

In addition, the local data also lines up with studies that have shown the vaccine to be about 99% effective at preventing hospitalization and death. The five fully vaccinated residents who have been hospitalized were 0.02% of the total who have gotten the shot.

Sergienko said public health

“Had we seen more vaccine uptake in the earlier part of vaccine availability, we would not be seeing as extensive of an outbreak as we are now. If you have less than half of the population fully vaccinated, you’re going to have more transmission.”

— Dr. Eric Sergienko, Tuolumne County interim health officer

experts said from the beginning that the vaccine would not be 100% effective, though they have proven to be more so than they initially hoped and better than the typical 50% effectiveness of vaccines for other diseases.

The reason why more vaccinated people have been testing positive in recent weeks is due to how prevalent the disease has become within the community, Sergienko said.

“Had we seen more vaccine uptake in the earlier part of vaccine availability, we would not be seeing as extensive of an outbreak as we are now,” he said. “If you have less than half of the population fully vaccinated, you’re going to have more transmission.”

Data reported by the CDC showed there were 23,674 residents in the county, roughly 43.5% of the total population, who were fully vaccinated as of Wednesday.

Experts say the target is to get at least 70% of the total population vaccinated, with the U.S. as a whole currently at 49.9% and California at 53.3%.

As a result of lagging vaccination rates and surging case numbers, governments and private employers have begun implementing more policies that require people to be vaccinated or wear a mask and get tested if they’re not.

The state Department of Public Health announced two new statewide mandates on Thursday, one of which requires all health care workers to be fully vaccinated or receive their second dose by Sept. 30.

About 90% of doctors that work for Adventist Health Sonora are fully vaccinated, according to Jaquelyn Lugg, spokeswoman for the hospital. She said they were in the process of verifying the vaccination status of all other employees.

“We strongly recommend all staff be vaccinated as soon as possible,” she said on Wednesday before the new state health order that gives health care workers no other choice but to be vaccinated by the end of September.

The second state health order on Thursday directs all hospitals, skilled nursing facilities and intermediate care facilities to verify that all visitors are fully vaccinated, or have tested negative 72 hours before indoor visits.

Adventist Health Sonora announced earlier this week that most patients would no longer be able to have visitors at all, with the exception of pediatric, maternity care and endof-life care patients each allowed one at a time as scheduled by hospital staff.

All visitors must be at least 18 years or older, wear masks at all times, and be screened for COVID-19 symptoms.

Both hospital staff and county officials have pleaded for more residents to get vaccinated, which they say are a provably safe and effective way of ending the pandemic that began in the U.S. early last year.

The county Board of Supervisors is also soon expected to consider requiring the roughly 670 county employees to show proof they are vaccinated, or get tested weekly and wear a mask while at work.