Studies assess responses, reactions to vaccines; long-term effects of COVID-19 infection

Pregnant women developed immunogenicity from the mRNA vaccines, according to a study published by JAMA on May 13. It included a convenience sample of 30 pregnant, 16 lactating, and 57 neither pregnant nor lactating women who were vaccinated. They all had binding, neutralizing, and functional non-neutralizing antibody responses as well as CD4 and CD8 T-cell responses; binding and neutralizing antibodies were also observed in infant cord blood and breast milk. After the second vaccine dose, fever was reported in four pregnant women (14%), seven lactating women (44%), and 27 nonpregnant women (52%).

Some people have delayed localized cutaneous reactions to the Moderna vaccine, according to a retrospective case series study published by JAMA Dermatology on May 12. It included 16 patients (median age, 38 years; 81% women) who had reactions at or near the injection site that were described as pruritic, painful, and edematous pink plaques. The reactions developed a median of seven days after vaccination (range, 2 to 12 days). All but one of the patients had the reaction to the first vaccine dose, and 11 of them had a similar reaction to the second dose. One skin biopsy was performed and showed mild, predominantly perivascular mixed infiltrate with lymphocytes and eosinophils, consistent with a dermal hypersensitivity reaction. The study authors concluded that the patients had delayed hypersensitivity reactions. “These reactions may occur sooner after the second dose, but they are self-limited and not associated with serious vaccine adverse effects. In contrast to immediate hypersensitivity reactions (eg, anaphylaxis, urticaria), these delayed reactions (dubbed ‘COVID arm’) are not a contraindication to subsequent vaccination,” they wrote.

Ongoing physical disability was common among patients who had been mechanically ventilated in an ICU for COVID-19, according to a Dutch study published by Critical Care Medicine on May 10. A total of 46 patients underwent a comprehensive physical assessment, pulmonary function testing, and chest CT three months after discharge. Six-minute-walk distance was below 80% of predicted in 48% of patients, and these patients with impaired physical performance had more muscle weakness, lower lung diffusing capacity, and higher intermuscular adipose tissue area than the others. The study authors concluded that physical sequelae were common in patients who had severe COVID-19 and appear to be multifactorial, involving both the lungs and skeletal muscle architecture.

A post-COVID-19 clinic reported on the clinical characteristics of its first 100 patients in a study published by Mayo Clinic Proceedings on May 11. Three quarters of the patients had not been hospitalized for COVID-19, and they presented a mean of 93 days after infection (mean age, 45 years; 68% women; mean BMI, 30.2 kg/m²). Presenting symptoms included fatigue (80%), respiratory symptoms (59%), and neurologic symptoms (59%), followed by subjective cognitive impairment, sleep disturbance, and mental health symptoms; 23% had pre-existing respiratory conditions and 34% had pre-existing mental health conditions. Most lab and imaging studies were normal or nondiagnostic, the authors said. About a third of patients reported difficulties performing basic activities of daily living, and only about a third had fully returned to work. The study authors highlighted how these patients' characteristics differed significantly from those associated with severe COVID-19 and recommended that testing be used judiciously in this population, given the rarity of significant findings.

Most dialysis patients who had COVID-19 maintained antibodies to SARS-CoV-2 at least six months after infection, according to a study published by Annals of Internal Medicine on May 18. It used plasma from 2,215 dialysis patients who had evidence of COVID-19 infection as of July 2020; 93% had an assay-detectable response (IgG index value ≥1). Sixty percent had a high response in July (IgG ≥10) and 76% of those responses remained high in December. The adjusted median response declined gradually, and this trend did not vary by age group, sex, race/ethnicity, or diabetes status. “A slow and continual decline in median antibody levels over time was seen, but no indication that subgroups with impaired immunity had a shorter-lived humoral response was found,” the study authors concluded.