Pfizer-BioNTech COVID-19 Vaccine May Reduce Risk of Long COVID in Older Adults

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Adults aged 50 years and older who received BNT162b2 bivalent COVID-19 vaccine (Comirnaty; Pfizer-BioNTech) had approximately half the odds of developing long COVID than unvaccinated adults, according to new data presented at IDWeek 2024, held October 16-19, in Los Angeles, CA.

Findings from a prospective study of older adults who tested positive for SARS-CoV-2 infection and reported 1 or more acute symptoms of COVID-19 showed that those vaccinated with BNT162b2 were less likely than unvaccinated participants to report ≥2 long COVID symptoms (27% vs 44.4%; adjusted OR 0.50, 95% CI 0.28-0.88) and ≥3 symptoms (16.5% vs 34.9%; adjusted OR 0.43, 95% CI 0.24-0.79) between 4 weeks and 6 months after infection.

“Long COVID includes new or persisting symptoms, signs, and health conditions impacting ≥1 organ/system following the acute phase of COVID-19. The clinical presentation of long COVID varies across patients and estimates of burden depend on the definition used,” investigators wrote in the study abstract.

They continued: “Randomized controlled trials and real-world evidence studies have shown the safety, efficacy and effectiveness of BNT162b2 in preventing the risk of infection and severe outcomes. Evidence on the real-world effectiveness of the BNT162b2 COVID-19 Vaccine against long COVID symptoms remains scarce.”

Researchers recruited US adults aged 50 years or older who tested positive for SARS-CoV-2 infection via RT-PCR or rapid antigen at CVS Health and reported ≥1 acute symptom of COVID-19 between March 2 and May 18, 2023. Participants self-reported the presence or absence of each of 30 long COVID symptoms at 4 weeks, 3 months, and 6 months after SARS-CoV-2 testing via an online questionnaire, according to the abstract.

The CDC’s definition of long COVID (ie, new-onset or symptoms persisting ≥4 weeks after acute infection) was operationalized as the presence of ≥2 or ≥3 new or persistent symptoms consistent with long COVID during the study period. Investigators computed the OR of long COVID for vaccinated versus unvaccinated adults using mixed-effects logistic models. The models were adjusted for multiple covariates, including sociodemographic characteristics (eg, age, sex, race/ethnicity, social vulnerability index), variables for time, and the number of acute symptoms on testing day.

A total of 277 adults (mean age, 62.3 years; 65.7% women; 69.3% White) were recruited and included in the study, of whom 172 (62%) self-reported receipt of BNT162b2 bivalent and 105 (38%) were not vaccinated, according to the results. All participants reported being symptomatic during the entire study follow-up (ie, ≥1 long COVID symptom through month 6) and 38.3% of the cohort had a comorbid condition. Among adults who received BNT162b2, the mean time since the last dose was 168 days.

Researchers also reported that the prevalence of ≥2 and ≥3 long COVID symptoms at month 6 following the positive test was 33.1% and 23%, respectively, among the total cohort. Absolute vaccine effectiveness ranged between 50%-57% across the 2 long COVID definitions.

“Despite high levels of immunity, especially among older adults, the post-pandemic burden of long COVID remains high, but is significantly lower for those vaccinated,” investigators stated.

The research team emphasized that these results may not be generalizable to prior or future SARS-CoV-2 variants, time periods, and populations excluded from the study, such as asymptomatic adults aged less than 50 years. Also, because all data collected were self-reported, the results may be subject to “missingness, errors, recall bias, social desirability bias and selection bias associated with survey drop-off,” they wrote.

Reference: Di Fusco M, Rudolph A, Lupton LL, et al. Effectiveness of BNT162b2 COVID-19 vaccination against long COVID among older adults: A nationwide study. Presented at: IDWeek 2024; October 16-19, 2024; Los Angeles, CA, Poster P-2060.