Virus World

COVID-19 vaccine effectiveness declined to 66% among a cohort of health care workers after delta became the predominant SARS-CoV-2 variant, according to a report in MMWR. However, a second report in the journal showed that unvaccinated people in Los Angeles County were around five times more likely to be infected and approximately 29 times more likely to be hospitalized with COVID-19 than vaccinated people.  “Vaccines are not bug zappers, and the efficacy that really matters is not against any infection but against severe infection,” Amesh A. Adalja, MD, a senior scholar at the Johns Hopkins Center for Health Security, told Healio. “By that standard,” Adalja said, “the vaccines are performing extremely well, even in the face of the delta variant. Chasing mild and/or clinically insignificant cases that occur after vaccination is of marginal value.” In the first study, Ashley Fowlkes, ScD, an epidemiologist on the CDC COVID-19 Response Team, and colleagues tested health care personnel, first responders and other essential workers from eight locations in six U.S. states weekly for COVID-19 from Dec. 14, through April 21.  Of a total of 4,217 participants, 3,483 (83%) were fully vaccinated. Of those who were vaccinated, 2,278 (65%) received the Pfizer-BioNTech vaccine, 1,138 (33%) received the Moderna vaccine and 67 (2%) received the Johnson & Johnson shot.

According to Fowlkes and colleagues, the adjusted vaccine effectiveness against COVID-19 dropped to from 91% (95% CI, 81%-96%) during the months before the delta variant predominated to 66% (95% CI, 26%-84%) during the period of delta predominance. “This trend should be interpreted with caution because [vaccine effectiveness] might also be declining as time since vaccination increases and because of poor precision in estimates due to limited number of weeks of observation and few infections among participants,” the authors wrote. In the second study, Jennifer B. Griffin, PhD, supervising epidemiologist at the Los Angeles County Department of Public Health, and colleagues assessed rates of infection and hospitalization among people aged 16 years or older from May 1 through July 25 and found that, during the study period, COVID-19 cases caused by the delta variant increased from 8.6% to 91.2% in fully vaccinated individuals, from 0% to 88.1% in partially vaccinated people, and from 8.2% to 87.1% in those who were not vaccinated. Among 43,127 cases of SARS-CoV-2 infection, 10,895 (25.3%) occurred in fully vaccinated people, 1,431 (3.3%) in partially vaccinated people and 30,801 (71.4%) in unvaccinated participants.

“On July 25, the SARS-CoV-2 infection rate among unvaccinated persons was 4.9 times and the hospitalization rate was 29.2 times the rates among fully vaccinated persons,” they reported. Among those who were fully vaccinated, 3.2% were hospitalized, 0.5% were admitted to the ICU and 0.2% required mechanical ventilation, according to the researchers. Among those who were partially vaccinated, 6.2% were hospitalized, 1% were admitted to the ICU, and 0.3% needed ventilation. Among unvaccinated individuals, 7.6% required hospitalization, 1.5% were admitted to the ICU, and 0.5% required ventilation. “The findings in this report are similar to those from recent studies indicating that COVID-19 vaccination protects against severe COVID-19 in areas with increasing prevalence of the SARS-CoV-2 delta variant,” Griffin and colleagues wrote. “Efforts to increase COVID-19 vaccination coverage, in coordination with other prevention strategies, are critical to preventing COVID-19-related hospitalizations and deaths.”

Study Cited Published in MMWR (Aug. 27, 2021):

 http://dx.doi.org/10.15585/mmwr.mm7034e4 

Because of the fast-spreading Delta variant, health officials are renewing calls for people to wear face masks — even if they're fully vaccinated against COVID-19. Last week we told you that if anything looked likely to roll back our newfound pandemic freedoms, it was the Delta variant. Sure enough, it is. On Monday, the Los Angeles County Department of Public Health advised all residents to wear masks while they’re in public indoor spaces — even if they’re fully vaccinated against COVID-19.  It may seem like a mixed message. After all, the county reminded people that “fully vaccinated people appear to be well protected from infections with Delta variants.” And as far as scientists can tell, that appears to be true. But no vaccine is perfect. The county has confirmed at least 10 coronavirus infections involving the Delta variant among people who were fully vaccinated. None required hospital care, most likely thanks to the immune-system boost they got from the vaccine.

The Delta variant, which was first identified in India, has also been found in three county residents who were partially vaccinated and 110 who were unvaccinated. These are the people health officials are most worried about. Scientists estimate that Delta is 60% more transmissible than the Alpha variant from the United Kingdom, which in turn is 50% more transmissible than the original coronavirus strain. That means Delta spreads more than twice as readily as the version of the virus that sparked the global pandemic. Among coronavirus samples sequenced in the U.S. in the two-week period that ended June 5 (the most recent reporting period available), 10% were Delta, according to the Centers for Disease Control and Prevention. In the prior two weeks, this variant accounted for just 2.9% of samples sequenced.  In addition, by June 5, Delta made up nearly 35% of samples analyzed in Iowa, Kansas, Missouri and Nebraska, and 25% of those in Colorado, Utah, Montana, Wyoming and the Dakotas. In California, Delta accounts for 14.5% of coronavirus samples that have been sequenced so far in June, making it the third-most common variant in the state. With that in mind, asking everyone to wear masks in supermarkets, movie theaters, offices, retail stores and other indoor venues sounds like a way to be safe instead of sorry.

“Until we better understand how and to who the Delta variant is spreading, everyone should focus on maximum protection with minimum interruption to routine as all businesses operate without other restrictions, like physical distancing and capacity limits,” L.A. County officials explained in a statement. L.A.’s advice aligns with that of the World Health Organization, which advises people to “wear a mask, especially in crowded, closed and poorly ventilated settings,” even after they’ve been vaccinated. The CDC, on the other hand, still says people who’ve been fully vaccinated don’t need to wear masks or worry about social distancing. It’s unclear if Delta will prompt officials here to reinstate other safety measures for those who are vaccinated. Even if coronavirus spread accelerates, California’s vaccine coverage is high enough to prevent another devastating surge. (Contrast that with South Africa, where less than 1% of the population is vaccinated. The Delta variant is fueling a third wave of infections there that’s on track to top the previous two, prompting President Cyril Ramaphosa to impose a sweeping set of new restrictions that includes a ban on indoor and outdoor gatherings, earlier curfews for nonessential businesses and the suspension of leisure travel in and out of the country’s most populous province.)  But the more a virus spreads, the more chances it has to mutate. And the more it mutates, the more chances it gets to acquire a genetic change that reduces the efficacy of vaccines or medicines. “It’s quite simple: More transmission, more variants. Less transmission, less variants,” WHO Director-General Tedros Adhanom Ghebreyesus said Friday. “That makes it even more urgent that we use all the tools at our disposal to prevent transmission.”

Including masks.

LOS ANGELES  — A man who mocked COVID-19 vaccinations died this week at a Los Angeles-area hospital after contracting the virus. Stephen Harmon was 34. Harmon died on Wednesday at Corona Regional Medical Center, about an hour’s drive east of Los Angeles. Stephen Harmon posted photos of himself in his hospital bed, wrote that he had pneumonia and critically low oxygen levels and was going to be intubated. In a tweet Wednesday, Harmon wrote: “Don’t know when I’ll wake up, please pray,” KCBS-TV reported. Three days before his death, Stephen Harmon tweeted: “If you don’t have faith that God can heal me over your stupid ventilator then keep the Hell out of my ICU room, there’s no room in here for fear or lack of faith!”  Before his hospitalization, Harmon had made fun of vaccination efforts on social media.  “I got 99 problems but a vax ain’t one,” he said in a tweet last month. On July 8, he posted: “Biden’s door to door vaccine ‘surveyors’ really should be called JaCovid Witnesses. #keepmovingdork.” Harmon’s death was “unbelievably demoralizing,” Dr. Oren Friedman, who treats COVID-10 patients at Cedars-Sinai Medical Center in Los Angeles, told KCBS-TV. He said the number of COVID-19 admissions had increased tenfold.  “Virtually every single person that is getting sick enough to be admitted to the hospital has not been vaccinated,” Friedman said.

California has seen escalating numbers of COVID-19 infections, led by the highly transmissible delta variant that has proliferated since the state fully reopened the economy last month. The vast majority of new cases are among unvaccinated people, and health officials have pleaded for people to get the shots. On Friday, the state Department of Public Health reported nearly 8,000 new cases a day earlier and the testing positivity rate over seven days had jumped to more than 5% after dipping below 1% only a few weeks ago. Los Angeles County, which has about a fourth of the state’s population, reported more than 3,000 new cases for the first time since February. There were 655 people with COVID-19 in hospitals, a jump of more than 200 people in a week, according to county figures. Harmon attended Hillsong Church in Los Angeles. Founder Brian Houston called him “one of the most generous people I know.” “As a church, our focus is on the spiritual well-being of the people in each of our local communities. On any medical issue, we strongly encourage those in our church to follow the guidance of their doctors,” Houston said in a statement to KCBS-TV. “While many of our staff, leadership and congregation have already received the COVID-19 vaccine, we recognize this is a personal decision for each individual to make with the counsel of medical professionals.”

The news comes as millions of Americans show no signs they will heed health officials and ring in the New Year safely.  Los Angeles is being severely impacted from a post-Thanksgiving surge in COVID-19 cases, as Americans across the country gather for Christmas despite health warnings.  The city has seen a four-fold increase in cases, with patients dying at the rate of one every ten minutes in Los Angeles County. The news comes as millions of Americans show no signs they will heed health officials and ring in the New Year safely, and the number of coronavirus cases across the U.S. is pushing doctors and nurses to the limit. More than 7 million people cleared the Transportation Security Administration for flights out of U.S. airports in the week before Christmas, CBS News' Michael George reports. The number is less than half the number of travelers from 2019, but still outpaced Thanksgiving travel volume, the previous record-high since the pandemic began. "If what happens over the winter holiday break is at all the same as what happened or even half of what happened over the Thanksgiving holiday, we're in deep trouble," Los Angeles County public health official Dr. Barbara Ferrer warned.

Dr. Stephen Patterson, who works at a hospital in nearby Riverside, said the rise in cases also saw a significant change in patient demographics. "We are still seeing a great number of those individuals that are part of our vulnerable populations — the elderly, those with chronic illnesses," Patterson said. "But, we are also seeing people who are in the 20s and 30s and early 40s." Although new vaccines have shown promise in the fight against the pandemic, Patterson urged Americans to think about their day-to-day actions and their effects. "Think about those decisions that you make — 'Will I take my mask off here, or will I decide that I would like to go out to eat here,' and those kinds of things, which can increase the risk that you yourself could bring that home to your family or that you could bring it home to a loved one," he said.