from the French National Agency for the Safety of Medicines and Health Products (ANSM).
The rare condition — more common in men than in women — is characterized by the sudden onset of severe pain in the shoulder, followed by arm paralysis. Its etiopathogenesis is not well understood, but vaccines, in particular the flu vaccine, have been implicated in some cases, the report states.
Six serious cases of the syndrome related to the Comirnaty (Pfizer) vaccine were reported by healthcare professionals and vaccinated individuals or their family and friends since the start of the monitoring program. Four of these cases occurred from September 3 to 16.
All six cases involved patients 19 to 69 years of age — two women and four men — who developed symptoms in the 50 days after vaccination. Half were reported after the first dose and half after the second dose. Four of the patients are currently recovering; the outcomes of the other two are unknown.
In the case of the Spikevax vaccine (Moderna), two cases of Parsonage-Turner syndrome were reported after vaccination (plus one that occurred after 50 days, which is currently being managed). The onset of symptoms in these two men — one in his early 30s and one in his early 60s — occurred less than 18 days after vaccination. One occurred after the first dose and one after the second dose. This timing indicates a possible link between the syndrome and the vaccine. Both men are currently in recovery.
This signal of mRNA vaccines is now “officially recognized,” according to the Pfizer and Moderna reports.
It is also considered a “potential signal” in the Vaxzevria (AstraZeneca) pharmacovigilance report, released October 8, which describes eight cases of Parsonage-Turner syndrome after vaccination.
Safety profile of mRNA COVID vaccines in youth
Between June 15, when children 12 years and older became eligible for vaccination, and August 26, there were 591 reports of potential adverse events — out of 6 million Pfizer doses administered — in 12- to 18-year-old children.
Of the 591 cases, 35.2% were deemed serious. The majority of these were cases of reactogenicity, malaise, or postvaccine discomfort (25%), followed by instances of myocarditis and pericarditis (15.9% and 7.2%, respectively). In eight of 10 cases, one of the first symptom reported was chest pain.
Myocarditis occurred in 39.4% of people after the first injection (mean time to onset, 13 days) and 54.5% after the second (mean time to onset, 4 days). Recorded progress was favorable in nearly nine of 10 cases.
Pericarditis occurred in 53.3% of people after the first injection (mean time to onset, 13 days), and 40.0% after the second (mean time to onset, 4 days).
Three cases of multisystem inflammatory syndrome in children (MISC) were reported after monitoring ended.
For this age group, “all reported events will continue to be monitored, especially serious events and multisystem inflammatory syndrome in children,” report authors conclude.
Data for adverse events after the Moderna vaccine remain limited, but the report stipulates that “the adverse events reported in 12- to 18-year-olds who received an injection do not display any particular pattern, compared with those reported in older subjects, with the exception of a roughly 100-fold lower incidence of reported adverse effects in the 12- to 17-year age group.”
No safety warnings for pregnant women
The pharmacovigilance report — which covered the period from December 27, 2020 to September 9, 2021 — “raises no safety warnings for pregnant or nursing women with any of the COVID-19 vaccines.” In addition, two recent studies — one published in JAMA and one in the New England Journal of Medicine — have shown no link between spontaneous miscarriage and mRNA vaccines.
“Moreover, it should be stressed that current data from the international literature consistently show that maternal SARS COV-2 infection increases the risk for fetal, maternal, and neonatal complications, and that this risk may increase with the arrival of the Alpha and Delta variants,” they write. “It is therefore important to reiterate the current recommendations to vaccinate all pregnant women, regardless of the stage of pregnancy.”
Some adverse effects, such as thromboembolic effects, in utero death, HELLP (hemolysis, elevated liver enzymes, and low platelets) syndrome, and uterine contractions, will continue to be monitored.
Questions regarding menstrual disorders
As for gynecological disorders reported after vaccination, questions still remain. “In most of the reported cases, it is difficult to accurately determine whether the vaccine played a role in the occurrence of menstrual/genital bleeding,” the authors of the pharmacovigilance monitoring report state.
“Nonetheless, these cases warrant attention,” they add, and further discussions with the French National Association of Obstetricians and Gynecologists and the French Society of Endocrinology are needed in regard to these potential safety signals.
A version of this article first appeared on Medscape.com.