In the midst of a summer wave of COVID-19 infections across the nation, a timely study has delved into the evolving risk of long Covid and its trajectory over the course of the pandemic.
Research findings indicate that while the likelihood of developing long-term COVID-19 has diminished since the onset of the pandemic, it remains substantial, particularly among individuals who have not received vaccination against the virus.
A recent analysis by the federal Agency for Healthcare Research and Quality, published in June, revealed that approximately 7% of American adults—equivalent to about 18 million people—have experienced long Covid. Harvard economist David Cutler estimated in 2022 that the total cost of long-term COVID-19 to the nation amounted to $3.7 trillion, representing 17% of the country’s pre-Covid gross domestic product.
Published on Wednesday in the New England Journal of Medicine, the new study draws on extensive data mining and advanced machine learning techniques applied to millions of medical records from the Department of Veterans Affairs. It suggests that both the human and financial impacts of long COVID-19 are likely to continue growing.
Researchers from Washington University in St. Louis and the VA Health System conducted a comprehensive study to assess how the risk of lingering symptoms related to long-term COVID-19 has evolved throughout different phases of the pandemic, considering varying COVID-19 variants and vaccination statuses.
The study, which included over 441,000 individuals who contracted COVID-19 between March 2020 and January 2022 and lived at least 30 days after infection, compared their medical records with more than 4.7 million people who visited the VA for reasons unrelated to COVID-19 during the same period.
Initially, during the first year of the pandemic with the ancestral coronavirus strain and limited immunity, approximately 1 in 10 Covid-19 patients developed symptoms consistent with long Covid within a year of their initial infection.
The introduction of vaccines marked a significant shift, halving the risk of long-term COVID-19 during the Delta variant wave in the summer of 2021. However, for those unvaccinated during this period, around 10% continued to experience lingering symptoms post-infection.
With the Omicron variant’s emergence in late 2021, the study found that 3.5% of vaccinated individuals developed long-term COVID-19 after the acute phase, compared to 7.7% of those who remained unvaccinated.
The study’s findings are limited by its predominantly White male VA patient population, which may not fully represent the diversity of the general public. For instance, recent research indicates a potentially higher incidence of long-term COVID-19 among pregnant individuals compared to the broader population.
These insights highlight the complex interplay between Covid-19 variants, vaccination status, and the risk of long-term symptoms, underscoring ongoing challenges and areas for further investigation in managing post-Covid health outcomes.”
The recent study from Washington University and the VA Health System underscores the evolving understanding of long-term COVID risk amidst changing COVID-19 variants and vaccination efforts. However, it leaves some important considerations unexplored.
Notably, the study does not differentiate between individuals who received only their primary series of COVID-19 vaccines and those who also received recommended booster shots to maintain immunity against evolving virus strains. Additionally, it does not delve into the potential impact of natural immunity acquired from prior infections, an area of interest for future research according to Dr. Ziyad Al-Aly, the senior study author.
Dr. Al-Aly estimates that approximately three-quarters of the observed decrease in long Covid risk since the early stages of the pandemic can be attributed to the widespread vaccination efforts. Vaccines play a crucial role in aiding the immune system to suppress viral load and clear the virus more effectively, potentially reducing the persistence of active virus thought to contribute to long Covid symptoms.
Dr. Hector Bonilla from Stanford’s Post-Acute Covid-19 Syndrome Clinic emphasizes the pivotal role of vaccination in mitigating long-term COVID-19, noting a significant decline in new cases of lingering symptoms among vaccinated individuals compared to earlier stages of the pandemic.
However, despite these advancements, the study underscores that around 3 out of 100 vaccinated individuals who contract COVID-19 may still develop long-term COVID-19, highlighting the ongoing substantial risk. This risk, though reduced, remains a significant concern for public health experts like Dr. Daniel Griffin from Columbia University, who stresses the persistent impact of long-term COVID-19 on individuals’ health and well-being.
As the virus continues to evolve, both through vaccination and changes in the virus itself, understanding and addressing the complexities of long Covid remain critical priorities in managing the broader health outcomes of the pandemic.”
“Despite a decrease since the early days of the pandemic, new cases of long Covid continue to emerge, highlighting ongoing challenges in patient care and treatment development.
Dr. Al-Aly emphasizes that this study and others underscore the critical need for increased funding and coordinated care for long Covid patients. He stresses the urgency for further research into effective treatments.
“I don’t believe the US is sufficiently addressing this problem,” Dr. Al-Aly stated. “While there’s a desire to move forward, millions of people are still suffering from long Covid, and unfortunately, more will continue to do so even with declining numbers.”
“There’s currently no comprehensive plan to tackle this issue,” he added firmly, “and that’s unacceptable.”