As the COVID-19 pandemic continues into its second winter, more and more vaccinated people have contracted the virus.
According to the Kern County Public Health Services Department, 4,236 of these so-called breakthrough cases have occurred since Jan. 21, roughly 6.8 percent of the total.
Yet doctors say the percentage of vaccinated individuals testing positive for coronavirus remains relatively low, and is a sign that the vaccines are holding up well. What’s more, the symptoms displayed by the relatively few vaccinated people who become sick have been milder than in the unvaccinated, and nearly all vaccinated who end up in intensive care units have significant comorbidities.
“It’s like with seat belts,” said Dr. Ghassan Jamaleddine, chief medical officer at Adventist Health Kern County. “It doesn’t mean that accidents aren’t going to happen, or that it’s going to prevent all injuries, but they will definitely prevent injury and death. There is no vaccine that is 100 percent. We know that, but it’s quite effective. It’s still very, very effective.”
Over the past two weeks, roughly 6.8 vaccinated people per 100,000 residents have tested positive for COVID-19 every day. That compares with 28.5 unvaccinated people per 100,000 residents who have tested positive over the same time period.
Health experts continue to push for vaccinations because they have proved very effective at keeping people out of hospitals. As the weather turns colder and flu season threatens to bring about a secondary surge in patients, vaccines are seen as critical to keeping the hospitals from being overwhelmed.
There have only been 185 post-vaccine hospitalizations in Kern County since Jan. 21, compared with 2,718 unvaccinated hospitalizations, evidence of the vaccines’ efficacy at preventing severe illness.
“For any virus, you’re going to get breakthrough cases, whether it’s the flu or COVID or anything like that. The bigger issue is what happens with these breakthrough cases,” said Dr. Hemmal Kothary, chief medical officer for Mercy Hospital Southwest. “What we’ve found is in the majority of these breakthrough cases, people get sick, they get better and they’re fine. The key is they stay out of the hospital. That’s what the vaccine does. It’s designed to keep them out of the hospital and keep them from passing away.”
Typically, infections occur when the COVID-19 virus populates the nasal passage and replicates faster than antibodies can be produced. Vaccines were very effective at stopping the original version of the virus, but the delta variant replicates faster than the original, and can lead to a greater number of breakthrough cases.
The relatively low vaccination rate in Kern County could contribute to a heightened number of breakthrough cases as it gives the virus more opportunity to infect vaccinated hosts. Those over the age of 65 or individuals who have compromised immune systems are more susceptible to breakthrough cases as well, since they may not produce as many antibodies as the young.
Still, the vaccines have proved robust against fighting off the delta variant, especially when compared to previous vaccines.
“In the past, the FDA would regularly approve vaccines if they were able to demonstrate 50 percent or more efficacy against the target pathogen,” said Dr. Glenn Goldis, chief medical officer at Kern Medical. “The fact that we have vaccines today that are 90 to 95 percent effective speaks to the amazing technology behind the mRNA vaccine.”
The doctors say severe illness in vaccinated individuals almost always involves one or more significant comorbidities, like a chronic kidney disease or organ transplant.
As health experts look to the future, they see vaccines as critical to preventing a fourth wave. In areas of the state with high vaccination rates, infections have remained low, and so have breakthrough cases.
“As a county, we are doing really bad in the vaccination rates compared to the whole state,” said Dr. Hany Aziz, a pulmonary and critical care doctor at Adventist Health. “When you call your colleagues in L.A. or in Orange County and they have a few patients, and here, half of the ICU is filled, that’s when we say we have to do better here getting the vaccine in the arms of the people here.”