PORTLAND, Ore — As the delta variant surges, Oregon's COVID-19 case numbers are rising along with breakthrough cases, which occur when a fully vaccinated person is infected with the virus.
On Friday, the Oregon Health Authority (OHA) held a press conference to discuss the rapid spread of the delta variant. OHA released a report this week that says 19% of the 12,514 cases reported in July were breakthrough cases.
The OHA pointed to the Centers for Disease Control and Prevention's hospitalization surveillance system that tracks severe COVID-19 cases. It looked at 7,000 patients age 65 and older from February through April of 2021.
The study determined the Pfizer and Moderna vaccines were 91-96% effective in reducing the risk of hospitalization. The Johnson & Johnson vaccine was 84-85% effective in reducing the risk of hospitalization.
Dr. Melissa Sutton, OHA's medical director of respiratory viral pathogens, said, "while these data were collected before the delta variant became the dominant variant in Oregon, we are confident that these estimates will remain very high even as the delta variant circulates. We believe this because we have vaccine effectiveness data from several other countries demonstrating very high protection against hospitalization and death from the delta variant."
She also pointed out the 4,196 breakthrough cases reported in Oregon through July are a very small percentage of the 2.3 million fully vaccinated Oregonians.
"The proportion of vaccine breakthrough cases is expected to increase as transmission increases in the community and more people are vaccinated, and does not mean the vaccines are working less effectively," Sutton said.
Dr. Marcel Curlin with Oregon Health and Science University told KGW in an interview that he feels the growing number of breakthrough cases indicate that those who are fully vaccinated should not let their guard down.
"If you got the vaccine, that's really good and its going to be helpful and it's going to increase your safety by a lot," said Curlin. "It's very important to get the vaccination. But you're not bulletproof."
To date, more than 90% of cases that have required hospitalization in Oregon have occurred in unvaccinated people, OHA said. 7% of breakthrough cases required hospitalization, and 1% have died.