Respiratory Diseases Roundup

Nirmatrelvir-Ritonavir Lacks Benefit for Patients With Long COVID, CDC Updates Recommendations for “Triple Threat” Vaccines, and More

Anthony Calabro, MA

Nirmatrelvir-Ritonavir Safe, But Does Not Show Benefits for Patients With Long COVID1
In a randomized clinical trial of 155 participants with postacute sequelae of SARS-CoV-2 infection (PASC, also known as “Long COVID”), a 15-day course of nirmatrelvir-ritonavir (NMV/r) was considered safe but ultimately did not improve the symptoms of PASC.

Researchers developed the 15-week blinded, placebo-controlled, randomized clinical trial from November 2022 to September 2023 at Stanford University in Palo Alto, CA. The study participants were adults who were experiencing moderate-to-severe PASC symptoms for at least 3 months (fatigue, brain fog, body aches, cardiovascular symptoms, shortness of breath, or gastrointestinal symptoms). Researchers randomized the study participants 2:1 with either oral nirmatrelvir-ritonavir (300 mg and 100 mg) or with placebo-ritonavir (PBO/r) twice daily for 15 days.

The results of the study showed no statistically significant difference in severity outcome across the six symptoms of PASC at 10 weeks between the NMV/r and PBO/r groups. No statistically significant between-group differences were found at 10 weeks in several different measures, including the Patient Global Impression of Severity or Patient Global Impression of Change scores, summative symptom scores. Additionally, no significant change from baseline to 10 weeks was found in PROMIS fatigue, dyspnea, cognitive function, and physical function measures.

“The results of this randomized clinical trial showed that a 15-day course of NMV/r in a population of patients with PASC was generally safe but did not demonstrate a significant benefit for improving select PASC symptoms in a mostly vaccinated cohort with protracted symptom duration,” the authors concluded. “Further studies are needed to determine the role of antivirals in the treatment of PASC.”

CDC Recommends Updated COVID, Influenza Vaccines for Fall, Winter 20242
The CDC is recommending updated COVID and influenza vaccines ahead of the fall and winter virus season.

“Our top recommendation for protecting yourself and your loved ones from respiratory illness is to get vaccinated,” Mandy Cohen, MD, MPH, director of the CDC, said in a press release. “Make a plan now for you and your family to get both updated influenza and COVID vaccines this fall, ahead of the respiratory virus season.”

For COVID-19, CDC recommends everyone aged 6 months and older receive an updated 2024-2025 COVID-19 vaccine whether they have ever previously been vaccinated with a COVID-19 vaccine or not. This recommendation will take effect as soon as the new vaccines are available.

Similarly, the CDC recommends everyone 6 months of age and older, with rare exceptions, receive an updated 2024-2025 influenza vaccine to reduce the risk of being diagnosed with the infection. The updated 2024-2025 influenza vaccines will all be trivalent and will protect against an H1N1, H3N2, and a B/Victoria lineage virus.

It is safe to receive COVID-19 and influenza vaccines at the same visit, the CDC noted in its press release.

While the CDC recommends influenza vaccination as long as influenza viruses are circulating, September and October remain the best times for most people to get vaccinated.

Nirsevimab Therapy Effective Against RSV-Associated Bronchiolitis Hospitalization3
Researchers who conducted a recent prospective, multicenter, matched case-control study found that nirsevimab therapy was effective in reducing the risk of hospitalized respiratory syncytial virus (RSV)-associated bronchiolitis in infants younger than 12 months of age.

Although nirsevimab is a monoclonal antibody that fights against RSV, the authors noted that its effectiveness against RSV-associated bronchiolitis is unclear. An effective treatment could curb the 3 million yearly hospitalizations due to RSV, which is the leading cause of bronchiolitis.

The study included 1035 patients 12 months of age or younger who were hospitalized due to either RSV-associated bronchiolitis (case patients; n = 690) or for conditions unrelated to RSV infection (matched control patients; n = 345) between October 15 and December 10, 2023.

Researchers calculated the primary outcome—effectiveness of nirsevimab therapy against hospitalization for RSV-associated bronchiolitis—using multivariate conditional logistic-regression models with adjustment for confounders.

The results showed that nirsevimab therapy was effective against hospitalization for RSV-associated bronchiolitis. The overall estimated adjusted effectiveness was 83% (95% confidence interval [CI], 73.4 to 89.2). The effectiveness of nirsevimab therapy against RSV-associated bronchiolitis resulting in critical care was 69.6% (95% CI, 42.9 to 83.8). Its effectiveness against RSV-associated bronchiolitis resulting in ventilatory support was 67.2% (95% CI, 38.6 to 82.5).

“This real–world study evaluating the effectiveness of nirsevimab within 3 months of nationwide implementation indicated that nirsevimab prophylaxis was effective against RSV-associated bronchiolitis leading to hospitalization among infants younger than 12 months of age, including those with severe cases that led to PICU admission and ventilatory support,” the authors concluded.

CDC Updates RSV Vaccination Recommendation for Older Adults4
In June, the CDC updated its recommendation for the use of respiratory syncytial virus (RSV) vaccines in individuals 60 years. The CDC now recommends:

  • Everyone aged 75 years and older should receive the RSV vaccine.
  • Those who are 60 to 74 years with certain chronic medical conditions, such as lung or heart disease, or they live in nursing homes, should receive the RSV vaccine.

According to the CDC, the updated recommendation for those 60 years of age and older was made to simplify RSV vaccine decision-making for clinicians and the public. The recommendations were based on analyses of RSV disease burden among people 60 and older, as well as both RSV vaccine effectiveness and cost-effectiveness studies. These studies included the first real-world data since RSV vaccines were recommended for people aged 60 years and older, the CDC press release noted.

“The CDC has updated its RSV vaccination recommendation for older adults to prioritize those at highest risk for serious illness from RSV,” Dr Cohen, said in a press release. “People 75 or older, or between 60 to 74 with certain chronic health conditions or living in a nursing home should get one dose of the RSV vaccine to provide an extra layer of protection.”

References

  1. Geng LN, Bonilla H, Hedlin H, et al. Nirmatrelvir-ritonavir and symptoms in adults with postacute sequelae of SARS-CoV-2 infection: the STOP-PASC randomized clinical trial. JAMA Intern Med. Published online June 7, 2024. doi:10.1001/jamainternmed.2024.2007
  2. CDC recommends updated 2024-2025 COVID-19 and flu vaccines for fall/winter virus season. News release. CDC Newsroom; June 27, 2024. Accessed August 8, 2024. https://www.cdc.gov/media/releases/2024/s-t0627-vaccine-recommendations.html.
  3. Assad Z, Romain AS, Aupiais C, et al. Nirsevimab and hospitalization for RSV bronchiolitis. N Engl J Med. 2024;391(2):144-154. doi:10.1056/NEJMoa2314885
  4. CDC updates RSV vaccination recommendation for adults. News release. CDC Newsroom; June 26, 2024. Accessed August 8, 2024. https://www.cdc.gov/media/releases/2024/s-0626-vaccination-adults.html