The European Centre for Disease Prevention and Control (ECDC) and the European Medicines Agency (EMA) today issued a joint statement that agrees with a recent World Health Organization (WHO) recommendation that COVID-19 vaccines be switched for the fall to a monovalent (single-strain) vaccine that contains an XBB lineage strain.

The groups said though current vaccines are effective at preventing hospitalization, severe disease, and death, protection wanes over time as new SARS-CoV-2 variants emerge. They added that XBB strains are dominant in Europe and other parts of the world and that monovalent vaccines are a reasonable choice for providing protection against current and emerging strains.

Also, the ECDC and EMA recommended simplified recommendations for immunization campaigns in the fall, including a single dose for people older than 5 years, that revaccinations stick with a 3-month minimum interval, and that people with weakened immune systems may need extra doses based on national recommendations.

In the United States, the Food and Drug Administration (FDA) vaccine advisory group will discuss COVID vaccine strategy at a meeting on June 15.

Menstrual cycles may lengthen by up to 1 day following COVID-19 vaccination, but the effect is temporary and vaccination makes little difference in cycle regularity, bleed length, heaviness of bleed, or menstrual pain, according to a study yesterday in Vaccine.

Since COVID-19 vaccines were first introduced for emergency use in North America in early 2021, women have shared anecdotal accounts on social media that their menstrual cycles changed following vaccination.

This prospective cohort study was based on the cycles of 1,137 participants who enrolled in Pregnancy Study Online (PRESTO), a preconception cohort study of couples trying to conceive, during January 2021 to August 2022. The women were not using fertility treatments, were ages 21 to 45, and lived in the United States or Canada.

The participants completed surveys at baseline and every 8 weeks for up to 12 months. They answered questions on vaccination and menstrual cycle characteristics, including cycle regularity, cycle length, bleed length, heaviness of bleed, and menstrual pain.

At the beginning of the study, no participants had been vaccinated against COVID-19. Participants either completed 6 follow-up questionnaires (13.8%), conceived before 12 months (64.6%), initiated fertility treatment (11.1%), stopped trying to conceive (2.0%), or were lost to follow-up or withdrew from the study (8.5%).

Short-term changes in menstrual cycle characteristics likely do not translate into meaningful differences in fertility.

A total of 437 participants (38.4%) received at least one COVID-19 vaccine dose during the study.

The only statistically significant finding was an average 1.1-day-longer menstrual cycles after receiving the first dose of COVID-19 vaccine (95% confidence interval [CI], 0.4 to 1.9) and an average 1.3-day-longer cycles after receiving the second dose (95% CI, 0.2 to 2.5). There were no changes to bleeding or pain, and by cycle two following vaccination the participants reported a return to their baseline.

"Taken together, these results indicate that short-term changes in menstrual cycle characteristics likely do not translate into meaningful differences in fertility," the authors concluded.

COVID-19 took a small but significant toll on children's health in India, with a higher newborn death rate, less consumption of solid or semisolid foods, and lower rates of physical growth, suggests a study published yesterday in JAMA Network Open.

Researchers from Korea University and Harvard University estimated the status of 26 health indicators among 125,812 children pre-pandemic (June 17, 2019, to February 29, 2020) and after it began (March 1, 2020, to May 20, 2021).

The researchers used data from the National Family Health Survey in India, a country with the world's second most COVID-19 infections and third most deaths as of January 2023.

Greatest decline in vaccination rates

After the pandemic began, there was a slight but significant increase in the newborn death rate (0.49 percentage points), a decline in feeding and nutrition (eg, 4.22-percentage-point reduction in solid or semisolid food intake), and an increase in physical growth (eg, 1.87-percentage-point increase in underweight).

The greatest decline was seen in vaccination rates, with 7.74- and 6.51-percentage-point reductions in receipt of the first dose of the diphtheria, pertussis, and tetanus (DPT) and polio vaccines, respectively. Other indicators, many related to health services, either stayed the same or improved slightly. Rates of diarrhea and respiratory infection improved, which the study authors said those findings could be due to the promotion of interpersonal hygiene to quell viral transmission.

"Mixed results from this analysis suggested that adverse consequences of COVID-19 and national lockdown were countered, to some extent, by emergency relief programs," the study authors wrote.

Adverse consequences of COVID-19 and national lockdown were countered, to some extent, by emergency relief programs.

For instance, the Indian government launched a program in 2020 to provide 5 kilograms (kg; about 11 pounds) of grains and 1 kg (2.2 pounds) of legumes monthly to about two thirds of the population. "This initiative may explain the relatively constant or minimally worsened patterns in child nutrition status before and after the outbreak," the researchers wrote. "It also underscored the need to sustain relief programs in nonpandemic times to promote children's health."

A new report from the Public Health Agency of Canada shows an increase in certain healthcare-associated infections (HAIs)—including antimicrobial-resistant (AMR) ones—in Canadian acute care hospitals.

Data collected from 88 Canadian sentinel acute care hospitals from January 2017 through December 2021 show that rates of methicillin-resistant Staphylococcus aureus (MRSA) bloodstream infections (BSIs) rose by 35%, climbing from 0.84 to 1.13 infections per 10,000 patient-days. The increase was driven primarily by community-associated (CA) cases, which climbed by 80% over the study period while healthcare-associated cases remained stable.

The study authors suggest the increase in CA-MRSA BSIs may be linked to a growing CA-MRSA reservoir in Canada, and that strategies that target the reduction and prevention of MRSA, such as screening and eradication of MRSA carriage, may reduce the overall burden of MRSA BSIs.

Vancomycin-resistant Enterococcus (VRE) BSIs increased by 43% (from 0.23 to 0.33 infections per 10,000 patient-days). The vast majority of VRE BSIs (89.9%) were healthcare-associated. Carbapenemase-producing Enterobacterales (CPE) infections remained low but rose from 0.03 to 0.06 infections per 10,000 patient-days from 2017 to 2018 (a 166% increase).

Drop in C difficile rates

The one HAI that saw a decline over the study period was Clostridioides difficile infection (CDI). Overall CDI rates fell by 11%, dropping from 5.68 to 5.05 infections per 10,000 patient-days—a decline the authors note is in line with global trends.

A total of 31 Candida auris isolates were identified in Canada from 2011 to 2021. More than one-third (38.7%) were considered multidrug-resistant.

"Consistent and standardized surveillance of epidemiologic and laboratory HAI data are essential to providing hospital practitioners with benchmark rates and informing infection prevention and control and antimicrobial stewardship policies to help reduce the burden of HAI and the impact of AMR in Canadian acute care hospitals," the authors wrote.

Consistent and standardized surveillance of epidemiologic and laboratory HAI data are essential.

Global flu activity continues to decline, driven by falling transmission in Northern Hemisphere countries, but some Southern Hemisphere countries such as Australia and Chile are reporting rises, the World Health Organization (WHO) said in its latest update, which covers roughly the first half of May.

Australia's flu levels rose in most states, according to the WHO. National data suggest the season started early and that cases have more than doubled over the past 5 weeks, with children ages 10 and under infected at higher rates than other groups, Australia's ABC News reported.

Elsewhere in the Southern Hemisphere, markers suggest that South Africa's flu season has started, and severe acute respiratory infections are on the rise in New Zealand. In Chile, flu positivity and cases are above average for this time of year.

At national flu labs, 71.06% of respiratory samples that were positive for flu were influenza A, and, of subtyped influenza A samples, nearly 69% were the 2009 H1N1 strain. Of subtyped influenza B viruses, all belonged to the Victoria lineage.