Respiratory Diseases Roundup

Vaccine Hesitancy, Rising Avian Influenza Cases, Reducing the Risk of Multisystem Inflammatory Syndrome in Children, and More

Miranda Manier, BA

RSV Vaccine Hesitancy and Low Vaccine Uptake1

Vaccination rates for influenza, COVID-19, and respiratory syncytial virus (RSV) remain low, particularly among high-risk groups. The CDC’s 2024 data reveals that 35% of US adults have received their influenza vaccine, and 18% have received the latest COVID-19 booster shot, below the target goal of 70% vaccination coverage. RSV vaccines, which were introduced in 2023, have shown promise, particularly for older adults and infants, but uptake has been slow. In a 2023 study, only 27% of eligible adults ages 65 and older had received the RSV vaccine.

Experts attribute vaccine hesitancy to misinformation and political debates surrounding health measures. Vaccine-related misinformation, especially on social media platforms, continues to influence individuals' willingness to get vaccinated, despite evidence of the safety and efficacy of these vaccines. The WHO has warned that vaccine hesitancy is one of the top 10 global health threats, as it could undermine efforts to combat respiratory diseases like RSV, influenza, and COVID-19.

The CDC and the American Academy of Pediatrics (AAP) emphasize that vaccines for RSV, influenza, and COVID-19 are crucial in preventing severe disease, hospitalizations, and deaths, especially among vulnerable populations like adults ages 65 and older, children, and immunocompromised individuals.

FDA Grants Emergency Use Authorization for Pemivibart Monoclonal Antibody for COVID-192

The FDA has granted emergency use authorization (EUA) for pemivibart, a monoclonal antibody treatment for individuals with weakened immune systems. Pemivibart has shown 81% efficacy in preventing symptomatic COVID-19 in clinical trials, offering a treatment option for individuals who may not respond well to vaccines, such as cancer patients, organ transplant recipients, and those with other immunocompromised conditions.

Pemivibart was tested against adintrevimab, another monoclonal antibody, with both treatments showing similar efficacy in reducing the risk of severe illness. The trials, which involved 3,500 participants from various high-risk groups, revealed a 36% reduction in the rate of hospitalization or death due to COVID-19 in the pemivibart group compared to placebo. Experts stress that further studies are needed to evaluate the long-term safety, durability, and effectiveness of pemivibart across a broader population, particularly in patients with long-term COVID-19 effects or those at the highest risk for complications.

Researchers are also continuing to monitor the effectiveness of monoclonal antibodies as new variants of SARS-CoV-2 emerge. Studies suggest that pemivibart is effective against multiple variants, including omicron and its subvariants, making it a key option for treating patients with breakthrough infections, especially when combined with other therapies like antivirals.

Early Detection of Avian Influenza Through Wastewater Monitoring3

Two recent cases of avian influenza in young people have raised concerns about the H5N1 virus. A teenager in British Columbia, Canada, is in critical condition after being diagnosed with the virus, marking the country's first locally acquired case. The teen, whose age and sex have not been disclosed, initially presented with fever, coughing, and conjunctivitis. The symptoms later progressed to acute respiratory distress, despite the absence of underlying health conditions. This case follows a milder infection in a child from California, who tested positive for avian influenza, though neither child had known exposure to infected animals.

While both cases have not shown evidence of person-to-person transmission, the discovery of a genetic mutation in the virus suggests it may be adapting to humans. In addition, the virus has continued to spill over into various mammal species, including dairy cows, which could complicate tracing the source of infection. Despite most avian influenza cases being mild, experts warn that the severity of infections in younger populations, such as the Canadian teen, could indicate a higher risk of severe disease.

In response to the growing concern over avian influenza, wastewater monitoring has emerged as a key tool for early detection. A recent study highlighted how wastewater samples from Texas detected H5N1 genetic material more than a month before confirmed outbreaks were reported in livestock. Researchers emphasize that this method offers an effective way to track the virus's spread in both animals and humans, potentially enabling quicker interventions to limit further transmission.

Study: Pfizer-BioNTech COVID-19 Vaccine Reduces MIS-C Risk in Children4

A recent study investigating the relationship between COVID-19 vaccination and the risk of developing multisystem inflammatory syndrome in children (MIS-C) highlights the protective effects of the Pfizer-BioNTech vaccine. MIS-C is a rare but serious condition that can occur after SARS-CoV-2 infection in children under 21. The study compared the incidence of MIS-C between vaccinated and unvaccinated children aged 5–17 years.

In the 12–17 year-old age group, the study found that there were 66 new cases of MIS-C among 872,936 unvaccinated children, while only seven cases were reported among the 2,117,575 vaccinated children. In the 5–11 year-old group, 51 cases occurred in 2,113,725 unvaccinated children, compared to nine cases among 1,221,293 vaccinated children.

The results of the study showed that unvaccinated children were at a significantly higher risk of developing MIS-C compared to vaccinated children. The incident rate ratio (IRR) for the 12–17 year-old group was 22.9 (95% CI: 10.5–49.8, P < .0001), indicating a much higher risk in unvaccinated children. In the 5–11 year-old group, the IRR was 3.3 (95% CI: 1.6–6.7, P = .0004), again showing a considerably higher risk among the unvaccinated.

References

  1. Lenthang M. Vaccination rates for flu and COVID are low this season, CDC says. NBC News. November 21, 2024. Accessed December 2, 2024. https://www.nbcnews.com/health/health-news/vaccination-rates-flu-covid-low-cdc-rcna181217
  2. Schmidt P, Li Y, Popejoy M. Immunobridging for Pemivibart, a monoclonal antibody for prevention of COVID-19. N Engl J Med. 2024;391:1860-1862. doi:10.1056/NEJMc2404555
  3. Young LJ. New bird flu cases in young people are raising concerns about mutating virus. Scientific American. November 21, 2024. Accessed December 2, 2024. https://www.scientificamerican.com/article/bird-flu-has-infected-two-young-people-heres-why-experts-are-concerned/
  4. Le Marchand C, Singson JR, Clark A, et al. Multisystem inflammatory syndrome in children (MIS-C) cases by vaccination status in California. Vaccine. 2024;42(51):7267-7274. doi:10.1016/j.vaccine.2024.126499