Long COVID Risk Varies by Age, Epidemic Period

The prominence and length of long COVID symptoms were varied based on epidemic period and between pediatric and adult patient populations, according to a study in PLOS One.¹ The study findings highlight the persistent need to conduct further monitoring of long-term symptoms while developing population-wide strategies for addressing specific age groups and COVID-19 variants.

“While it was initially believed that COVID-19 was mainly associated with acute symptoms, it is not uncommon for infected patients to report prolonged illness, often described as ‘long COVID,’” according to the University of Illinois Chicago.² “The CDC reported that even in young adults, without underlying medical conditions, recovery from COVID-19 can take a long time, with approximately 1 in 5 patients reporting not having returned to their usual state of health by 14 to 21 days.”

A recent landmark study from Japan reveals that the landscape of long COVID, clinically referred to as post-\acute sequelae of SARS-CoV-2, is significantly shaped by 2 primary factors: the age of the patient and the specific epidemic period in which they were infected.¹

For pharmacists on the front lines of patient care, understanding these shifting risk profiles is essential for effective symptom screening and medication management.^2,3

READ MORE: Same-Day COVID-19, Influenza Vaccination Does Not Increase Adverse Events

What the Data Says About Long COVID Risk

The retrospective cohort study tracked over 2600 individuals in Hiroshima between 2020 and 2024. Despite the risk of persistent symptoms generally declining since the Omicron variant became predominant, a significant subset of the population continues to face long-term health challenges.¹

The height of long COVID risk occurred during the Delta variant's dominance in late 2021, a period the CDC Museum timeline notes was characterized by a massive third wave of infections. During this era, nearly 47% of adults reported persistent symptoms 6 months after their acute illness, compared with only about 21% of those infected during the more recent 2024 Omicron period.^1,4

This evolution aligns with data from the WHO, which continuously monitors variants of concern and variants of interest like JN.1 to assess their potential for causing new waves.⁵

Age remains a critical predictor of recovery speed and symptom persistence. The Japan study highlights a stark contrast between age groups, showing that children, particularly those 12 years old or younger, recover much more rapidly than adults.¹

The prevalence of long COVID in children also remained at about one-quarter to one-third the rate of adults across all epidemic periods. Although pharmacists should remain vigilant for “brain fog” or coughs among pediatric patients’ long COVID symptoms, data suggests that, for those whose symptoms persist beyond 2 years, the impact on daily activities is significantly lower than in the adult population.

For adults, the outlook for significantly long-term symptoms is more sobering. The study found that symptoms persisting beyond the 2-year mark showed very little further resolution thereafter. Approximately 20% of adults infected before the Omicron era and 10% of those infected during later Omicron periods still reported symptoms at the 24-month milestone.¹

The Pharmacist’s Toolbelt for Addressing Long COVID

These findings underscore the importance of pharmacists identifying patients who may be experiencing a plateau in their recovery. Common symptoms such as fatigue, shortness of breath, and cognitive impairment can drastically reduce a patient's quality of life and complicate the management of other chronic conditions.^1-3

Pharmacists are uniquely positioned as the most accessible health care professionals to assist what researchers consider a “long-haul” population. By utilizing screening questionnaires as recommended, pharmacists can help identify patients whose symptoms have persisted past the standard 4-week acute phase or the 12-week threshold for long COVID.^2,3

Beyond identification, pharmacists play a vital role in medication optimization. This includes reviewing for adverse drug effects that might mimic long COVID symptoms, managing polypharmacy, and discouraging the use of unproven or potentially harmful supplements until more robust clinical data is available.

The role of vaccination also remains a central theme in long COVID management. Despite the Japan study focusing primarily on variant-specific trajectories, other research highlights that maintaining vaccine confidence is essential.³

Some anecdotal evidence suggests that vaccination can even lead to the improvement or resolution of certain lingering symptoms, such as gastrointestinal issues or the aforementioned brain fog. As the pandemic continues to evolve with new sublineages like KP.3.1.1, pharmacists must stay informed on the latest clinical guidelines and epidemiology to provide evidence-based care and empathy to a patient population that often feels dismissed by the broader medical community.^2,3,5

“This study demonstrated that the prevalence and duration of long COVID symptoms varied by epidemic period and between adults and children, with the highest risk observed during the Delta period and lower prevalence during the Omicron periods,” concluded the authors of the current study.¹ “Taken together, these findings underscore the importance of continued long-term monitoring and the development of clinical and public health strategies that address the distinct risks associated with different variants and age groups.”

READ MORE: COVID-19 Resource Center

REFERENCES

1. Sugiyama A, Takafuta T, Abe K, et al. Differences in the long-term course of post-COVID-19 symptoms in adults and children across epidemic periods: A retrospective cohort study in Japan, 2020–2024. PLoS ONE. 2026;21(5):e0348954. doi:10.1371/journal.pone.0348954

2. Lee C. What should I, as a pharmacist, know about long-COVID? University of Illinois Chicago. March 2021. Accessed July 6, 2026. https://dig.pharmacy.uic.edu/faqs/2021-2/march-2021-faqs/what-should-i-as-a-pharmacist-know-about-long-covid/

3. Gosser R, Anderson S, Blaszczyk A, et al. In it for the long haul: post-acute sequelae of severe acute respiratory syndrome coronavirus 2. J Pharm Pract. 2023 Oct;36(5):1048-1051. doi: 10.1177/08971900221088799.

4. CDC museum COVID-19 timeline. CDC. July 8, 2024. Accessed July 6, 2026. https://www.cdc.gov/museum/timeline/covid19.html

5. WHO COVID-19 dashboard. World Health Organization. 2024. Accessed July 6, 2026. https://data.who.int/dashboards/covid19/variants