Trending Topics: COVID-19 and Mpox Vaccine Updates and Doubling Syphilis Detection

Trending Topics From Infection Control Today

August 2024 COVID-19 Vaccine Approvals

The FDA announced on August 22, 2024, that it had approved and granted Emergency Use Authorization (EUA) for updated mRNA COVID-19 vaccines for the 2024-2025 season. These vaccines, from ModernaTX Inc. and Pfizer Inc, target the Omicron variant KP.2 strain, providing enhanced protection against severe illness, hospitalization, and death. The updated vaccines were formulated to address the most currently circulating variants.

Additionally, on August 30, 2024, the FDA granted an EUA for Novavax's updated COVID-19 vaccine, targeting the Omicron JN.1 strain. The vaccine is authorized for individuals aged 12 and older and aims to offer better protection against serious COVID-19 complications.

Peter Marks, MD, PhD, director of the FDA’s Center for Biologics Evaluation and Research, emphasized the importance of vaccination: “Vaccination continues to be the cornerstone of COVID-19 prevention. These updated vaccines meet the agency’s rigorous, scientific standards for safety, effectiveness, and manufacturing quality. Given waning immunity of the population from previous exposure to the virus and from prior vaccination, we strongly encourage those who are eligible to consider receiving an updated COVID-19 vaccine to provide better protection against currently circulating variants.

The CDC recommends COVID-19 vaccination for everyone aged 6 months and older.

Mpox Vaccine Update

On August 29, 2024, the FDA approved a new indication for ACAM2000, a vaccine initially designed for smallpox, now also authorized for preventing mpox in high-risk individuals. ACAM2000 is a live replicating vaccinia virus vaccine, and each recipient must receive an FDA-approved Medication Guide outlining potential risks and benefits.

Emergency Use Authorization Update: Pemgarda

On August 26, 2024, the FDA revised the EUA for Pemgarda (pemivibart), limiting its use based on the prevalence of COVID-19 variants resistant to the treatment. The EUA allows Pemgarda for pre-exposure prevention of COVID-19, contingent upon national variant frequencies.

These recent FDA updates highlight ongoing efforts to manage COVID-19 and mpox through targeted vaccinations and treatments.

Emergency Department Screening Significantly Increases Syphilis Detection

A National Institutes of Health (NIH)-supported study has found that offering optional syphilis tests to patients in a large emergency department (ED) more than doubled the detection of syphilis cases. Conducted in Chicago and involving nearly 300,000 ED encounters, the study showed that most people diagnosed with syphilis had no symptoms, highlighting the limitations of symptom-based testing alone. These findings were published in Open Forum Infectious Diseases on September 10, 2024.

The CDC reports a significant rise in syphilis cases, with an 80% increase in adult syphilis and a 183% rise in congenital syphilis between 2018 and 2022. Detecting asymptomatic cases through broader screening strategies is crucial, especially for populations with limited access to healthcare, such as pregnant women.

In the study, syphilis screening was offered to individuals between 18 and 64 years old, excluding those with a documented HIV diagnosis or those who had been tested for syphilis in the previous year. From June 2017 to May 2021, syphilis testing increased from 3.6% of ED encounters to 24.4% after the intervention. The number of presumed active syphilis cases increased from 161 to 624 during this period, with many cases diagnosed in asymptomatic individuals.

The screening also benefited pregnant individuals, where testing rose from 5.9% to 49.9%, and confirmed syphilis diagnoses increased from 2 to 15 cases. “With the recent dramatic rise in syphilis and congenital syphilis, there is an urgent need to identify strategies to increase screening and early diagnosis among priority populations, especially those with limited access to care, including limited or no prenatal care," the authors wrote. "This study demonstrates that the introduction of opt-out syphilis screening in the ED can have profound effects on screening and diagnosis rates among racial and ethnic minorities, those holding public insurance, women, and most strikingly, pregnant women."

This study, led by the University of Chicago’s Sections of Emergency Medicine and Infectious Diseases and Global Health, demonstrates that ED-based syphilis screening can help bridge gaps in diagnosis and treatment, particularly in high-risk populations and those with limited health care access.