COVID-19* / epidemiology

Background: Changes in the vaccine advisory process in the United States have disrupted immunization guidance, which reinforces the need for independent evidence review to inform decisions regarding immunization for respiratory viruses during the 2025-2026 season.

Methods: We conducted a systematic review of U.S.-licensed immunizations against coronavirus disease 2019 (Covid-19), respiratory syncytial virus (RSV), and influenza. We searched databases on PubMed/MEDLINE, Embase, and Web of Science for updates of the most recent review by the Advisory Committee on Immunization Practices (ACIP) Evidence-to-Recommendations for each disease, which was performed during the 2023-2024 period. Outcomes included vaccine efficacy and effectiveness against hospitalization, other clinical end points, and safety.

Results: Of 17,263 identified references, 511 studies met the inclusion criteria. Covid-19 mRNA vaccines against the XBB.1.5 subvariant had pooled vaccine effectiveness against hospitalization of 46% (95% confidence interval [CI], 34 to 55; from cohort studies) and 50% (95% CI, 43 to 57; from case-control studies) among adults and 37% (95% CI, 29 to 44) among immunocompromised adults. In a case-control study, vaccines against the KP.2 subvariant showed an effectiveness of 68% (95% CI, 42 to 82). Maternal RSV vaccination (for infant protection), nirsevimab for infants, and RSV vaccines in adults who were 60 years of age or older showed vaccine effectiveness of 68% or more against hospitalization. Influenza vaccination had a pooled vaccine effectiveness of 48% (95% CI, 39 to 55) in adults between the ages of 18 and 64 years and 67% (95% CI, 58 to 75) in children against hospitalization. Safety profiles were consistent with previous evaluations. The diagnosis of myocarditis associated with Covid-19 vaccines occurred at rates of 1.3 to 3.1 per 100,000 doses in male adolescents, with lower risk associated with longer dosing intervals. The RSVpreF vaccine was associated with 18.2 excess cases of Guillain-Barré syndrome per million doses in older adults; a significant association with preterm birth was not observed when the vaccine was administered at 32 to 36 weeks' gestation.

Conclusions: Ongoing peer-reviewed evidence supports the safety and effectiveness of immunizations against Covid-19, RSV, and influenza during the 2025-2026 season. (Funded by the Center for Infectious Disease Research and Policy and the Alumbra Innovations Foundation.).

Author/s:

Michael S. Abers, Jake Scott, Harleen K. Marwah, Nicole C. McCann, Eric A. Meyerowitz, Aaron Richterman, Derek F. Fleming, Caitlin M. Dugdale

The 2024 National Academies of Sciences, Engineering, and Medicine Long COVID Definition: What Clinicians Need to Know

Megan George — Wed, 06 Aug 2025 22:16:16 +0000

Date Added:

August 6, 2025

Journal/Publication:

Journal of General Internal Medicine

Publication Date:

March 10, 2025

URL:

The 2024 National Academies of Sciences, Engineering, and Medicine Long COVID Definition: What Clinicians Need to Know

Type:

Public Health Announcements

Format:

Article

DOI (1):

10.1007/s11606-025-09415-8

Keywords

COVID-19

Long COVID

post-acute sequelae of COVID-19

PMID (1):

40063321

MeSH

COVID-19* / epidemiology

COVID-19* / complications

COVID-19* / diagnosis

COVID-19* / therapy

chronic disease

Humans

National Academies of Science

Engineering

and Medicine

U.S.

Health and Medicine Division*

post-acute COVID-19 syndrome

SARS-CoV-2

United States/epidemiology

A definition of long-COVID from the National Academy of Medicine. James W. Mold, MD, MPH

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Millions of Americans affected by Long COVID (LC) report difficulty accessing care and support. One barrier is obtaining a diagnosis. In response, US federal agencies commissioned a National Academies of Sciences, Engineering, and Medicine (NASEM) committee to re-examine the existing federal definitions for LC. The Committee concluded that LC is "an infection-associated chronic condition (IACC) occurring after SARS-CoV-2 infection that is present for at least 3 months as a continuous, relapsing and remitting, or progressive disease state that can present as singular or multiple symptoms and/or diagnosable conditions." The full report was released in June 2024. We briefly highlight features and aspects of the definition that may help clinicians identify those who remain undiagnosed and improve care for all LC patients.

Author/s:

Lily Chu, Karyn Bishof, Abigail A Dumes, E Wesley Ely, Paule V Joseph, Andrea B Troxel

Nirmatrelvir or Molnupiravir Use and Severe Outcomes From Omicron Infections

Rowan Hutchins — Wed, 04 Oct 2023 05:00:00 +0000

Date Added:

October 4, 2023

Journal/Publication:

JAMA Network Open

Publisher:

AMA

Publication Date:

September 21, 2023

Issue:

Volume:

URL:

Nirmatrelvir or Molnupiravir Use and Severe Outcomes From Omicron Infections

Type:

Clinical Research Results

Format:

Article

DOI (1):

10.1001/jamanetworkopen.2023.35077

Keywords

PMID (1):

37733342

MeSH

COVID-19* / epidemiology

COVID-19 Vaccines

COVID-19 Drug Treatment

High risk outpatients with COVID (omicron type) appear to benefit from either molnupiravir or nirmatrelvir. James W. Mold, MD, MPH

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Question: What outcomes are associated with ritonavir-boosted nirmatrelvir or molnupiravir use for outpatient treatment of SARS-CoV-2 Omicron subvariants, particularly BQ.1.1 and XBB.1.5, in high-risk individuals?

Findings: In a cohort study of 68 867 patients who received a diagnosis of COVID-19 at Cleveland Clinic from April 1, 2022, to February 20, 2023, and who were at high risk of progressing to severe COVID-19, both nirmatrelvir and molnupiravir use were significantly associated with reductions in hospitalization and death. The association was observed across subgroups defined by age, race and ethnicity, date of diagnosis, vaccination status, previous infection status, and coexisting conditions.

Meaning: These findings suggest that both nirmatrelvir and molnupiravir can be used to treat nonhospitalized patients who are at high risk of progressing to severe COVID-19.

Author/s:

Lin, Dan-Yu, Huang, Shuaiqi, Abi Fadel, Francois

Outpatient Treatment for COVID-19

Rowan Hutchins — Wed, 27 Sep 2023 05:00:00 +0000

Date Added:

September 27, 2023

Journal/Publication:

JAMA

Publisher:

AMA

Publication Date:

August 16, 2023

URL:

Outpatient Treatment for COVID-19

Type:

Patient Education Materials

DOI (1):

10.1001/jama.2023.16666

Keywords

COVID-19

outpatient

PMID (1):

37585210

MeSH

COVID-19* / epidemiology

outpatients

Ritonavir

Information for patients about outpatient treatment options for COVID-19. James W. Mold, MD, MPH

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Outpatient Treatment for COVID-19

Author/s:

Raglow, Zoe, Malani, Preeti N., Petty, Lindsey A.

Evaluation of Waning of SARS-CoV-2 Vaccine–Induced Immunity

Rowan Hutchins — Tue, 06 Jun 2023 05:00:00 +0000

Date Added:

June 6, 2023

Journal/Publication:

JAMA Netw Open

Publisher:

American Medical Association

Publication Date:

May 3, 2023

Issue:

Volume:

URL:

Evaluation of Waning of SARS-CoV-2 Vaccine–Induced Immunity

Type:

Meta-analyses, Reviews, and Guidelines

Format:

Article

DOI (1):

10.1001/jamanetworkopen.2023.10650

Keywords

COVID-19

COVID-19 vaccine

'Vaccination

PMID (1):

37133863

MeSH

SARS-CoV-2

COVID-19 Vaccines

COVID-19* / prevention & control

COVID-19* / epidemiology

It looks like the COVID vaccines protect about as long as flu vaccines, 6 months for primary immunization, 9 months for the booster. Sounds like we will be getting one each year. James W. Mold, MD, MPH

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Importance Estimates of the rate of waning of vaccine effectiveness (VE) against COVID-19 are key to assess population levels of protection and future needs for booster doses to face the resurgence of epidemic waves.

Objective To quantify the progressive waning of VE associated with the Delta and Omicron variants of SARS-CoV-2 by number of received doses.

Data Sources PubMed and Web of Science were searched from the databases’ inception to October 19, 2022, as well as reference lists of eligible articles. Preprints were included.

Study Selection Selected studies for this systematic review and meta-analysis were original articles reporting estimates of VE over time against laboratory-confirmed SARS-CoV-2 infection and symptomatic disease.

Data Extraction and Synthesis Estimates of VE at different time points from vaccination were retrieved from original studies. A secondary data analysis was performed to project VE at any time from last dose administration, improving the comparability across different studies and between the 2 considered variants. Pooled estimates were obtained from random-effects meta-analysis.

Main Outcomes and Measures Outcomes were VE against laboratory-confirmed Omicron or Delta infection and symptomatic disease and half-life and waning rate associated with vaccine-induced protection.

Results A total of 799 original articles and 149 reviews published in peer-reviewed journals and 35 preprints were identified. Of these, 40 studies were included in the analysis. Pooled estimates of VE of a primary vaccination cycle against laboratory-confirmed Omicron infection and symptomatic disease were both lower than 20% at 6 months from last dose administration. Booster doses restored VE to levels comparable to those acquired soon after the administration of the primary cycle. However, 9 months after booster administration, VE against Omicron was lower than 30% against laboratory-confirmed infection and symptomatic disease. The half-life of VE against symptomatic infection was estimated to be 87 days (95% CI, 67-129 days) for Omicron compared with 316 days (95% CI, 240-470 days) for Delta. Similar waning rates of VE were found for different age segments of the population.

Conclusions and Relevance These findings suggest that the effectiveness of COVID-19 vaccines against laboratory-confirmed Omicron or Delta infection and symptomatic disease rapidly wanes over time after the primary vaccination cycle and booster dose. These results can inform the design of appropriate targets and timing for future vaccination programs.

Author/s:

Menegale, Francesco, Manica, Mattia, Zardini, Agnese, Guzzetta, Giorgio, Marziano, Valentina, d'Andrea, Valeria, Trentini, Filippo, Ajelli, Marco, Poletti, Piero, Merler, Stefano