BCG Vaccine May Protect Against Long COVID Symptoms

TOPLINE:

Administering the Bacillus Calmette-Guérin (BCG) vaccine during the active phase of COVID-19 may help protect against the development of long COVID.

METHODOLOGY:

A phase 3 clinical trial initiated in early 2020 investigated the effect of the BCG vaccine injected during active infection on COVID-19 progression in adults with mild or moderate COVID-19. The current study summarizes the 6- and 12-month follow-up data with a focus on long-COVID symptoms.
Patients who tested positive for severe acute respiratory syndrome coronavirus 2 were randomly assigned to receive either 0.1 mL of intradermal BCG (n = 191) or 0.9% saline placebo (n = 202) within 14 days of symptom onset and were followed up at 7, 14, 21, and 45 days and at 6 and 12 months postinjection.
Overall, 157 BCG (median age, 40 years; 54.1% women) and 142 placebo (median age, 41 years; 65.5% women) recipients completed the 6-month follow-up, and 97 BCG (median age, 37 years; 49.5% women) and 95 placebo (median age, 40 years; 67.4% women) recipients completed the 12-month follow-up.
The researchers primarily assessed the effect of the BCG vaccine on the development of the symptoms of long COVID at 6 and 12 months.

TAKEAWAY:

Hearing problems were less frequent among BCG recipients at 6 months compared with those who received placebo (odds ratio [OR], 0.26; 95% CI, 0.045-1.0; P = .044).
At 12 months, participants who received the BCG vaccine exhibited fewer issues with sleeping (P = .027), concentration (P = .009), memory (P = .009), and vision (P = .022) along with a lower long-COVID score (one-sided Wilcoxon test, P = .002) than those who received placebo.
At 6 months, BCG demonstrated a sex-specific paradoxical effect on hair loss, decreasing it in men (P = .031), while causing a slight, though statistically nonsignificant, increase in women.
Male sex was the strongest predictive factor for long COVID, cognitive dysfunction, and cardiopulmonary scores at both follow-up assessments.

IN PRACTICE:

“[The study] findings suggest that BCG immunotherapy for an existing ailment may be superior to prophylaxis in healthy individuals,” the authors wrote.

SOURCE:

The study was led by Mehrsa Jalalizadeh and Keini Buosi, UroScience, State University of Campinas, Unicamp, São Paulo, Brazil. It was published online on November 19, 2024, in the Journal of Internal Medicine.

LIMITATIONS:

Previous mycobacterial exposure was not tested among the study participants. A notable loss to follow-up, particularly at 12 months, may have introduced bias into the results.

DISCLOSURES:

The study was supported by the Coordination for the Improvement of Higher Education Personnel, Federal Government of Brazil, the General Coordination of the National Immunization Program, Ministry of Health (Brazil), and the National Council for Scientific and Technological Development-Research Productivity. The authors declared no conflicts of interest.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.