Underlying Conditions and the Higher Risk for Severe COVID-19

Opinion | When It Comes to Covid-19, Most of Us Have Risk Exactly Backward (Published 2020)

We aren’t very good at discussing trade-offs, but we need to make some during this pandemic.

You've Got COVID! Minimize Your Symptoms and Reduce Your Long COVID Risk

Essential guidance for managing acute COVID-19 to minimize symptoms and reduce Long COVID risk. Learn what to do when you test positive.

COVID-19 Vaccine Effectiveness and Safety for the 2026-2027 Respiratory Season

Importance SARS-CoV-2 remains a substantial cause of respiratory illness, morbidity, and mortality. Evidence to date has demonstrated that COVID-19 vaccines reduce the risk of severe disease, including hospitalization and death. Objective This systematic review identifies and summarizes newly published studies reporting on the effectiveness and safety of COVID-19 vaccines and COVID-19 epidemiology in the US. Evidence Review Cochrane Central Register of Controlled Trials, PubMed/MEDLINE, Embase, and Scopus were searched from August 1, 2025, through June 29, 2026. Studies were eligible if they reported on the effectiveness, efficacy, or safety of a US-licensed COVID-19 vaccine or SARS-CoV-2 epidemiology in the US. Findings From 11 829 identified references, 155 publications were eligible (15 randomized clinical trials, 84 observational studies with a comparator group, 38 product safety studies without a comparator group [single group], and 18 descriptive studies of disease burden). Consistent with prior evidence, studies reported that updated COVID-19 vaccines were associated with a reduction in the risk of hospitalization among both older adults (≥65 years; vaccine effectiveness [VE], 53.0%; 95% CI, 37.0%-65.0%; 2025-2026 season) and adults (18-64 years; VE, 54.0%; 95% CI, 1.0%-78.0%; 2024-2025 season). Maternal vaccination was associated with reduced risk of COVID-19–associated emergency department/urgent care encounters among individuals vaccinated (VE, 58.0%; 95% CI, 24.0%-77.0%) and with fewer COVID-19–related hospital contacts in the first 2 months of life among infants born subsequently (VE range, 50.0%-54.0%), regardless of trimester of vaccination. Vaccination was also associated with a significant reduction in COVID-19–related pediatric emergency department visits (9 months to 4 years; VE, 76.0%; 95% CI, 58.0%-87.0%). Vaccination was associated with a reduced risk of critical COVID-19 illness (intensive care unit admission or death) in immunocompromised adults (VE range, 32.0%-53.0%, depending on condition and other factors). Health care personnel who received 3 to 5 vaccine doses were less likely to develop laboratory-confirmed COVID-19 illness (VE, 41.0%; 95% CI, 34.0%-47.0%) and postacute COVID-19 symptoms (VE, 57.0%; 95% CI, 46.0%-66.0%) compared with those who received only 2 doses. Across adverse events of special interest (eg, stroke, thrombosis, myocarditis), safety profiles were consistent with those of previous reviews. No identified studies conducted under the updated guidance on extended dosing intervals for the primary series reported an increased risk of myocarditis or pericarditis. No new safety signals were reported in the recently published studies eligible for this updated review of US-licensed COVID-19 vaccines. Conclusions and Relevance COVID-19 vaccines were consistently associated with a reduction in the risk of hospitalization and other outcomes, including among individuals at high risk of severe COVID-19, such as infants, and those who were pregnant. No new safety concerns were identified.

Evidence mounts that Long Covid is damaging the hearts of those affected

There are also increasing signs that the condition can disrupt the autonomic nervous system

Vascular and inflammatory diseases after COVID-19 infection and vaccination in children and young people in England: a retrospective, population-based cohort study using linked electronic health records

Children and young people have higher risks of rare vascular and inflammatory diseases up to 12 months after a first COVID-19 diagnosis and higher risk of rare myocarditis or pericarditis up to 4 weeks after a first BNT162b2 vaccine, although the risk following vaccination is substantially lower than the risk following infection. These findings are of great importance for national policy makers and caregivers considering vaccination consent for children, and support the public health strategy of COVID-19 vaccination in children and young people to mitigate the more frequent and persistent risks associated with SARS-CoV-2 infection.

Vascular and inflammatory diseases after COVID-19 infection and vaccination in children and young people in England: a retrospective, population-based cohort study using linked electronic health records

Children and young people have higher risks of rare vascular and inflammatory diseases up to 12 months after a first COVID-19 diagnosis and higher risk of rare myocarditis or pericarditis up to 4 weeks after a first BNT162b2 vaccine, although the risk following vaccination is substantially lower than the risk following infection. These findings are of great importance for national policy makers and caregivers considering vaccination consent for children, and support the public health strategy of COVID-19 vaccination in children and young people to mitigate the more frequent and persistent risks associated with SARS-CoV-2 infection.

COVID-19 Vaccine Effectiveness and Safety for the 2026-2027 Respiratory Season

This Special Communication aims to identify and summarize the most recently published evidence evaluating the effectiveness and safety of US-licensed COVID-19 vaccines and report on the epidemiology of SARS-CoV-2 in the US.

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The Sick Times - Chronicling the Long COVID crisis

Chronicling the Long COVID crisis

Researchers link Long COVID to another virus | NHK WORLD-JAPAN News

Researchers in Japan have released findings showing that COVID-19 after effects, including fatigue, occur when a coronavirus infection activates another virus already inside the body.

Meta to roll back Covid-19 misinformation measures

Meta is revising its policies to take a regional approach towards countries that still have public health emergency declarations.

The unprecedented and deadly cruise ship hantavirus outbreak, explained

This is not COVID," and other reasons why risk to the public is currently low.

Severity of COVID-19 at elevated exposure to perfluorinated alkylates

Background The course of coronavirus disease 2019 (COVID-19) seems to be aggravated by air pollution, and some industrial chemicals, such as the perfluorinated alkylate substances (PFASs), are immunotoxic and may contribute to an association with disease severity. Methods From Danish biobanks, we obtained plasma samples from 323 subjects aged 30–70 years with known SARS-CoV-2 infection. The PFAS concentrations measured at the background exposures included five PFASs known to be immunotoxic. Register data was obtained to classify disease status, other health information, and demographic variables. We used ordered logistic regression analyses to determine associations between PFAS concentrations and disease outcome. Results Plasma-PFAS concentrations were higher in males, in subjects with Western European background, and tended to increase with age, but were not associated with the presence of chronic disease. Of the study population, 108 (33%) had not been hospitalized, and of those hospitalized, 53 (16%) had been in intensive care or were deceased. Among the five PFASs considered, perfluorobutanoic acid (PFBA) showed an unadjusted odds ratio (OR) of 2.19 (95% confidence interval, CI, 1.39–3.46) for increasing severities of the disease. Among those hospitalized, the fully adjusted OR for getting into intensive care or expiring was 5.18 (1.29, 20.72) when based on plasma samples obtained at the time of diagnosis or up to one week before. Conclusions Measures of individual exposures to immunotoxic PFASs included short-chain PFBA known to accumulate in the lungs. Elevated plasma-PFBA concentrations were associated with an increased risk of a more severe course of COVID-19. Given the low background exposure levels in this study, the role of exposure to PFASs in COVID-19 needs to be ascertained in populations with elevated exposures.

Long COVID may affect up to 5% of healthcare workers in hospitals, new data suggest

Newborns immunized against RSV also had a 36% lower risk of infection with a life-threatening illness called invasive pneumococcal disease.