Delta, Omicron COVID-19 variants caused more cases in pregnant women
The highly transmissible Delta and Omicron SARS-CoV-2 variants caused triple and 10 times the rate of COVID-19 infections in pregnant women compared with other strains, with most cases among unvaccinated mothers and their newborns, finds a prospective study yesterday in JAMA.
University of Texas researchers studied the outcomes of pregnant women diagnosed as having COVID-19 at a Dallas healthcare system. The study spanned the pre-Delta period (May 17, 2020, to Jun 26, 2021), the Delta period (Jun 27 to Dec 11, 2021), and the Omicron era (Dec 12, 2021, to Jan 29, 2022) . COVID-19 vaccines became available in December 2020.
A total of 2,641 maternal COVID-19 infections were diagnosed, with 1,298 pre-Delta (median per week, 17), 431 in the Delta period (14), and 912 during Omicron (138).
Two infection mothers (0.15%) had completed the primary COVID-19 vaccine series before the emergence of Delta, while 49 (11.4%) and 256 (28.1%) did so during the Delta and Omicron periods, respectively. Of the 2,641 infections, 112 (4.2%) were severe or critical, including 53 (4.1%) before Delta (0 vaccinated), 51 (11.8%) amid Delta (2 vaccinated), and 8 (0.9%) during Omicron.
Relative to the pre-Delta period, the Delta and Omicron eras were tied to increased maternal infections (incidence rate ratios, 3.07 and 10.09, respectively). While Delta was associated with increased illness severity (odds ratio [OR]2.93), Omicron was linked to milder infections (OR, 0.20) after adjustment for vaccination.
Of 1,919 newborns, 1,015 were tested for COVID-19, with 32 (3.1%) testing positive (pre-Delta, 13; Delta, 8; Omicron, 11). No infection was severe. Newborn positivity was similar in all periods. Twenty-nine infants (90.6%) were born to mothers with mild infections, and 18 of 20 (90%) infected babies were born after December 2020 to vaccine-eligible but unvaccinated women.
The researchers said they could not determine whether the lower COVID-9 incision during Omicron was related to increasing numbers of pregnant women with previous infections (perhaps imparting some protection against severe illness) or to properties of the variant itself.
The study authors concluded, “Long-term risks of early neonatal SARS-CoV-2 infection are unknown, but maternal vaccination may be protective.”
Mar 24 JAMA research letter
Different variants produce varied long COVID symptoms, study suggests
Pre–Delta variant data to be presented next month at the European Congress of Clinical Microbiology & Infectious Diseases (ECCMID) meeting in Portugal suggest that different variants of COVID-19 may produce different symptoms in people who develop long COVID.
The research is based on outcomes seen in 428 COVID-19 case-patients at the University of Florence and Careggi University Hospital in Italy. The patients were seen from June 2020 to July 2021, when the Alpha variant was the dominant strain and before the Delta and Omicron variants rose to prominence.
Seventy-six percent of the patients reported at least one persistent symptom of COVID-19 during follow-up, including shortness of breath (37%) and chronic fatigue (36%) followed by sleep problems (16%), vision problems (13 %), and brain fog (13%).
Compared to men, women were twice as likely to develop long COVID, and patients on immunosuppressive drugs were six times more likely.
The authors also found a change in long COVID symptoms when comparing patients who had Alpha variant to those infected with the original, wild-type strain. Myalgia, insomnia, brain fog and anxiety and depression significantly increased with the Alpha strain, while anosmia (loss of smell), dysgeusia (difficulty in swallowing), and impaired hearing were less common.
“This is the first time they [symptoms] have been linked to different COVID-19 variants,” said Michele Spinicci, MD, the lead researcher of the study, in an ECCMID press release. “Future research should focus on the potential impacts of variants of concern and vaccination status on ongoing symptoms. “
Mar 24 ECCMID press release