Repeat COVID infections appear to predispose patients to disease, death
Repeat SARS-CoV-2 infections confer significant additional risk of adverse multi-organ medical conditions and poor outcomes such as hospitalization, diabetes, kidney disease, mental illness, death, and diseases affecting the lungs, heart, brain, blood, and musculoskeletal systems, suggests a study published yesterday in Nature Medicine.
Researchers at Washington University and the Veterans Affairs (VA) St. Louis Health Care System used the VA’s national healthcare database to estimate the risk of poor 6-month outcomes among 443,588 veterans who had one COVID-19 infection, 40,947 infected at least twice, and 5,334,729 uninfected controls from Mar 1, 2020, to Apr 6, 2022. Of those with at least two infections, most had two or three, and a few had four.
Compared with patients with no reinfection, repeat infection was tied to more than double the risk of death (hazard ratio [HR], 2.17) and more than three times the risk of hospitalization (HR, 3.32). Such patients were 3.5 times more likely to develop lung disease, 3.0 times more likely to have new-onset heart conditions, and 1.6 times more likely to have neurologic disease.
The greatest risks were in the 30 days after infection but were still evident at 6 months. The cumulative risks of repeat infection rose by the number of infections. “Reducing overall burden of death and disease due to SARS-CoV-2 will require strategies for reinfection prevention,” the authors wrote.
In a Washington University news release, senior author Ziyad Al-Aly, MD, clinical epidemiologist at the university’s medical school, said he has observed in recent months “an air of invincibility among people who have had COVID-19 or their vaccinations and boosters, and especially among people who have had an infection and also received vaccines.”
But the research shows the potential detriment of serial infections, he said: “Without ambiguity, our research showed that getting an infection a second, third or fourth time contributes to additional health risks.… Going into the winter season, people should be aware of the risks and practice vigilance to reduce their risk of infection or reinfection.”
Nov 10 Nat Med study
Nov 10 Washington University news release
High blood pressure linked to greater risk of severe COVID-19
In a study in PLOS One of more than 16,000 infected people in the United Kingdom, high blood pressure was found to be associated with a 22% higher odds of severe COVID-19, though successfully reducing blood pressure through medication was linked with a corresponding reduction in risk.
The study looked at medical records from the UK Biobank, a longitudinal prospective study initiated in 2006 that has recruited more than 500,000 men and women aged from 40 to 69 years. It included 16,134 peopleo who tested positive for COVID-19. Of those, 22% (3,584) developed severe COVID-19, and 40% (6,517) had high blood pressure.
All COVID-19 records from March 2020 through April 2021 were included in the study. The authors defined severe COVID-19 as a case that required hospitalization.
High blood pressure was associated with 22% higher odds of severe COVID-19 (odds ratio [OR], 1.22; 95% confidence interval [CI], 1.12 to 1.33) compared with normal blood pressure.
In those taking blood pressure medication, elevated systolic blood pressure (SBP) showed a dose-response relationship with severe COVID-19 (150 to 159 mm Hg vs 120 to 129 OR, 1.91; 95% CI, 1.44 to 2.53; >180 mm Hg versus 120 to 129 OR, 1.93; 95% CI, 1.06 to 3.51).
Angiotensin-converting enzyme inhibitors or angiotensin-II receptor blockers were not associated with altered risk of severe COVID-19, the authors said.
“Even though the mortality rate due to COVID-19 has been hugely reduced over the last year due to mutation, vaccination and effective treatments, this study highlights the importance of hypertension as a risk factor for COVID-19,” the authors concluded. “Our data suggest that further research is needed into the mechanisms driving hypertension as a risk factor for COVID-19 in case of novel, more severe strains or other viruses in the future.”
Nov 9 PLOS One study
COVID-19 cases rise in Australia, decline in Europe
As Australia approaches its summer season, a new wave of COVID-19 activity is under way, according to official and media reports.
Norelle Sherry, MBBS, with the Doherty Institute, told Australia’s ABC News this week that the wave is driven by multiple Omicron offshoots. BA.5 is still dominant, but scientists are also detecting the BA.5-descendent BQ.1 and the Omicron recombinant virus XBB. “We’re actually in more of a COVID soup—not my original phrase, but I think it’s definitely apt,” she told ABC.
In a related development, a Princess Cruise ship that traveled on a 12-day trip to New Zealand with 4,300 guests and crew on board will disembark in Sydney tomorrow with 800 people positive for COVID-19, the Sydney Morning Herald reported today. New South Wales health officials classified the ship outbreak as high impact, its highest level, meaning the ship isn’t able to maintain its critical services due to staff or resource shortages.
In other global developments, the European Centre for Disease Prevention and Control (ECDC) in its latest weekly update said COVID-19 cases and deaths continue to decline in the region and that hospitalizations are declining or stable. BA.5 is still dominant, and the proportion of BQ.1 is at 18.1%, up from 11.3% the previous week.
The European Medicines Agency (EMA) yesterday announced the approval of Sanofi’s adjuvanted vaccine that includes the spike protein of the Beta variant to be used as a booster for adults previously vaccinated with mRNA or adenovirus vaccines.
Also, China—experiencing a rise in COVID activity—has relaxed some of its measures, according to Reuters. It cut the quarantine period for contacts by 2 days and eased fines for airlines carrying passengers who test positive for COVID.
Nov 9 ABC News story
Nov 11 Sydney Morning Herald story
Nov 10 ECDC update
Nov 10 EMA announcement
Nov 11 Reuters story