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BOSTON -- Stopping respiratory illnesses before they start through new delivery systems and by such mundane work as analyzing a city's wastewater were among the early highlights at this year's meeting.

Intranasal Vaccine Shows Promise

At a press briefing, researchers suggested that those who dislike the idea of having to get poked by needles to prevent infection with SARS-CoV-2 may be able to sniff a vaccine instead.

Johanna Kaufmann, PhD, executive vice president for oncology and immunology at Codagenix, based in Cambridge, Massachusetts, reported that in a phase I study, two doses of a live-attenuated COVID-19 vaccine candidate known as CoviLiv produced a broad humoral and cellular immune response when administered intranasally.

The first-in-human trial was a primary vaccination series study conducted among healthy adults prior to the development of the mRNA vaccines that are now approved for broad public use, Kaufmann noted.

All participants exceeded a twofold increase in spike-specific IgG, with a geometric mean fold rise of 19.5 by day 57. Neutralizing antibodies at this timepoint were induced 2.6-fold with the microneutralization assay and 4.9-fold using the pseudovirus neutralization assays. On day 36 post-vaccination, interferon-gamma response by ELISpot increased 4.5-fold in the two-dose cohort and 2.5-fold in the one-dose cohort.

Kaufmann noted that CoviLiv does not require cold chain storage, making it easier to stockpile in areas that currently lack access to adequate refrigeration for vaccines. Furthermore, intranasal administration provides an alternative to intramuscular vaccines, which experts said could promote greater uptake in areas with lower vaccination rates.

"The study findings provide a glimpse into what could be the next generation of COVID-19 vaccines that provide differentiated protection to more people," she said. "Vaccine administration by nose and easier storage can increase access to vaccinations for underserved areas across the world."

There are currently no intranasal vaccines approved for use against COVID-19.

Wastewater as a Sentinel for Viruses Beyond COVID

Every time you flush the toilet, you are giving scientists clues about what respiratory viruses may be emerging, researchers suggested.

In a Canadian study in the city of Calgary, wastewater-based surveillance was able to accurately predict if the area was primed for outbreaks of seasonal diseases such as influenza A, influenza B, or respiratory syncytial virus (RSV).

"Just one flush can hold a lot of information. Wastewater surveillance equips public health experts, clinicians, policymakers, and the public with community-based, objective data to inform health and safety decisions against the flu and RSV," said Kristine Du, BSc, a lab technician at the Cumming School of Medicine at the University of Calgary. "Knowing what viruses are coming down the pike can help prepare individuals and communities appropriately."

At the press briefing, Du said viral signals in Calgary's wastewater correlated with weekly confirmed clinical cases for all three viruses. Influenza A peaked in Calgary's wastewater in November-December 2022; influenza B in February-April 2023; and RSV in November 2022-February 2023.

The data come from weekly collection of 24-hour composite wastewater samples from three treatment plants in Calgary from March 2022 to April 2023. The wastewater values were compared with clinical data reported by Alberta Health Services and reported as total cases and test positivity rates across Calgary and Alberta.

Moving forward, researchers said that onboarding additional respiratory viruses to wastewater surveillance capabilities will help provide a comprehensive assessment of viral respiratory disease activity.

Avoiding Infant Hospitalizations With the Maternal RSV Vaccine

Vaccinating pregnant women with the newly approved RSV vaccine may reduce hospitalizations and the financial resource burden that occurs when children under the age of 1 year are sickened by the infection, researchers suggested.

"The potential benefits of this vaccine underscore how important immunization is for helping prevent serious disease in infants and offering savings to our health system," said Amy W. Law, PharmD, director of global value and evidence at Pfizer, during the press briefing. "These findings provide evidence for expecting families, facing an exciting and changing time in their lives, with an option to offer protection for their child against severe respiratory illness."

Law reported that the vaccine is the first of its kind to produce antibodies in pregnant women to help prevent RSV infection in infants. Approximately 500,000 to 600,000 U.S. infants experience lower respiratory tract disease caused by RSV each year, and it is a leading cause of infant hospitalization.

The CDC's Advisory Committee on Immunization Practices recommended that pregnant women receive a single dose of Pfizer's prefusion F protein (RSVpreF) vaccine (Abrysvo) at 32 to 36 weeks' gestation to prevent lower respiratory tract RSV infection in infants.

Law said her data are based on a cohort model that depicted clinical outcomes and economic costs of RSV from birth to 1 year of age, lifetime consequences of premature death, and impacts of maternal vaccination among infants. The economic costs are based on cases and corresponding unit costs of direct care, such as hospitalizations, and indirect care, such as time spent caregiving.

The model suggested that a vaccination program for pregnant women with 3.7 million births in the U.S. each year would result in:

• A 50.8% decrease in hospitalizations
• A 31.8% decline in emergency department visits
• A 32.2% decline in outpatient clinic visits
• A decrease of $691.8 million in direct medical costs and $110 million in indirect costs

IDWeek is the joint annual meeting of the Infectious Diseases Society of America, the Society for Healthcare Epidemiology of America, the HIV Medicine Association, the Pediatric Infectious Diseases Society, and the Society of Infectious Diseases Pharmacists.