A new study published in Human Reproduction shows no evidence that COVID-19 vaccination in either male or female partners is linked to early or late miscarriages and that maternal vaccination shortly before conception has no impact on early (less than 8 weeks) miscarriage rates.

The study was based on outcomes seen in the Boston University School of Public Health’s Pregnancy Study Online (PRESTO), an ongoing study that follows participants from preconception through 6 months after delivery. The present study included 1,815 women from the United States and Canada who were followed from December 2020 through November 2022. The women were ages 21 to 45 years and were trying to conceive without the use of fertility treatment at enrollment.

Questionnaires were administered at enrollment and every 8 weeks thereafter and asked about general health, gestational health, COVID-19 infections, and COVID-19 vaccinations. Of all participants, 75% had received at least one dose of a COVID-19 vaccine by the time of conception.

Vaccinated women had slightly lower miscarriage rates

Overall, 446 (24.6%) participants experienced a miscarriage. The risk of miscarriage was 26.6% among unvaccinated women, 23.9% among women who had received more than one dose before conception, 24.5% among those who completed a full primary sequence before conception, and 22.1% among those who completed the sequence at or less than 3 months before conception.

No effect was seen on male vaccination status and miscarriage rates. The study adds to a growing body of literature showing no evidence that COVID-19 vaccines reduce fertility or increase miscarriage risk.

Our data indicated a slightly lower risk of miscarriage among vaccinated individuals.

"The rate of miscarriage among vaccinated individuals was not only comparable with that of PRESTO participants who conceived before the pandemic, but our data indicated a slightly lower risk of miscarriage among vaccinated individuals compared to unvaccinated individuals,” said lead author Jennifer Yland, an epidemiology PhD student at Boston University, in a press release.

Highly pathogenic avian flu outbreak struck poultry and commercial flocks in three more states, as the number of affected birds since the events began in early 2022 topped the 60 million mark, the US Department of Agriculture (USDA) Animal and Plant Health Inspection Service (APHIS) said its latest updates.

In Alabama, the virus was detected at a gamebird producer in Chilton County that has 296,500 birds, marking the first outbreak at a commercial farm in the state.

Elsewhere, the virus struck two backyard flocks in Alaska’s Matanuska Susitna County and a poultry farm in Washington’s Kittitas County.

The outbreaks are part of a rise in virus activity that began in early October and have pushed the number of affected birds to a record 60.03 million poultry or other commercial birds across 47 states since the Eurasian H5N1 clade first turned up in US poultry in early 2022.

• South Korea is reporting a sharp rise in malaria cases this year, the highest since 2011, according to the Korea Herald, which cites data from the Korea Disease Control and Prevention Agency. Of 719 cases reported as the middle of October, 657 were locally acquired.
• The Coalition for Epidemic Preparedness Innovations (CEPI) and Moderna have formed a strategic partnership to leverage Moderna’s mRNA vaccine platform to speed the development of vaccines against future viral disease threats. The effort, designed to boost global pandemic preparedness, is part of CEPI’s “100 Days Mission”, which has a goal of shrinking the vaccine development timeline to 100 days. In a statement, Moderna said the first part of the project will involve testing of a new artificial intelligence-generated designs and mRNA technology against a range viral families that pose the greatest health threats.
• The World Health Organization today recognized three countries in its South East Asia region for eliminating or interrupting disease transmission. They include Bangladesh for eliminating visceral leishmaniasis, Maldives for interrupting leprosy transmission, and South Korea for eliminating rubella.

From 46% to 61% of adults receiving mpox vaccination at two US public health clinics reported a decrease in sexual behaviors tied to viral transmission, including one-time encounters, sex partners, dating app– or sex venue–based sex, and group sex, according to a study published late last week in Sexually Transmitted Diseases.

The study, led by Centers for Disease Control and Prevention (CDC) researchers, involved 711 adults seeking mpox vaccination at two clinics in Washington, DC, who completed questionnaires from August to October 2022.

Median participant age was 32 years, 52.0% were White, 20.5% were Black, 14.6% were Hispanic, 7.9% were Asian, 2.0% were multiracial, 0.3% were American Indian/Alaska Native, and 9% had HIV. Most participants were men who have sex with men (MSM) (61.0%), 27.0% were women, and 3.8% were men who have sex with only women.

During the 2022 multicountry mpox outbreak, more than 30,000 mpox cases were reported, mainly among MSM. "Decreases in U.S. mpox cases were likely accelerated by a combination of vaccination and modifications to sexual behaviors associated with mpox virus transmission," the researchers wrote.

Greater share of Black, HIV-positive reported less risky sex

Many participants reported fewer one-time sexual encounters (60.8%), sex partners (54.3%), less dating app– or sex venue–facilitated sex (53.4%), and less group sex (45.6%). A total of 39% to 54% reported no change in these behaviors, and 0.4% reported an increase.

While reported cases of mpox continue to be low, individuals may return to behaviors and practices that they engaged in prior to the outbreak. In turn, behavior mitigation strategies may only be implemented as temporary protective measures, underscoring the importance of mpox vaccination for continued protection.

A greater proportion of Black participants reported decreases in all four behaviors since learning about mpox (61% to 76%), compared with White participants (41% to 54%). Also, a higher percentage of participants with HIV than those without HIV said they were engaging less in these activities (72% to 82% vs 43% to 59%).

"While reported cases of mpox continue to be low, individuals may return to behaviors and practices that they engaged in prior to the outbreak," the authors wrote. "In turn, behavior mitigation strategies may only be implemented as temporary protective measures, underscoring the importance of mpox vaccination for continued protection."

A new study in the Annals of Internal Medicine of US veterans prescribed nirmatrelvir–ritonavir (Paxlovid) during COVID-19 infections shows no difference in long-COVID rates among groups who took the antivirals and those who did not.

The study was based on 191,057 veterans with a first positive SARS-CoV-2 test result during January through July 2022. Among that group, 9,593 nonhospitalized patients were treated with Paxlovid, and outcomes were compared among their matched untreated cohorts for 31 post-COVID conditions (PCCs).

Follow-up lasted through January 2023 to allow for 6-month outcomes after treatment, the authors said.

Among participants prescribed the antiviral, 86% were men, median age was 66, and 17.5% were unvaccinated.

Our results suggest that considerations about PCCs may not be an important factor in COVID-19 treatment decisions.

There were no differences observed between participants treated with Paxlovid and their matched untreated comparators. The only benefit seen was a lowered combined risk for venous thromboembolism and pulmonary embolism (subhazard ratio, 0.65 [95% confidence interval [CI], 0.44 to 0.97]; cumulative incidence difference, −0.29 percentage points [95% CI, −0.52 to −0.05 percentage points]) in patients who took Paxlovid.

"Our results suggest that considerations about PCCs may not be an important factor in COVID-19 treatment decisions," the authors concluded.