Over the weekend, the World Health Organization (WHO) confirmed it began a Jynneos vaccination campaign in the Democratic Republic of the Congo (DRC) in an effort to stem an ongoing mpox outbreak.

The DRC has reported more than 30,000 suspected and laboratory-confirmed mpox cases this year, including 990 deaths. The outbreak has spread to 15 other African nations.

A total of 265,000 doses of Jynneos, donated by the European Union, were distributed in the DRC. According to the WHO, the vaccination campaign will be rolled out in 11 of the most affected health zones in Equateur, North Kivu, Sankuru, South Kivu, Sud-Ubangi, and Tshopo provinces.

Our top priority is to secure safe and effective vaccines for children in the next phase of vaccination

"Africa CDC remains committed to working closely with the DRC to ensure vaccines reach those who need them the most, while also working to strengthen health systems to prevent future outbreaks. Our top priority is to secure safe and effective vaccines for children in the next phase of vaccination," the Africa Centres for Disease Control and Prevention (Africa CDC) said in a press release announcing the start of the vaccine campaign. 

North Kivu province is first target 

Health workers in North Kivi province are among the first to receive the vaccines. North Kivi has been a hotspot for the current outbreak: 34% of the reported confirmed cases are individuals living in camps for internally displaced people, and approximately 75% of mpox cases in the province are among children 0 to 17, according to the latest situation report on the outbreak. 

Case investigations have shown mpox transmission in North Kivu is exclusively human-to-human, with about a third (34%) of the cases reporting sexual contact as the mode of transmission. Among those cases, over half are reported to occur in sex workers (52%).

Results from an online survey in Denmark describe fatigue and post-exertional malaise as prominent features 2 to 18 months after COVID-19 infections for both mild and severe cases. The study appeared today JAMA Network Open. 

The study was based on responses from 50,115 individuals (median age 57), of whom 25,249 (50.4%) were test positive and 24,866 (49.6%) were test negative at the time of study enrollment. The participants completed repeated, self-reported online questionnaires that collected information on fatigue.

"The index test date for the majority of test-positive and test-negative participants took place during the Omicron-dominant period," the authors said. 

When compared to COVID test-negative participants, test-positive participants had a significant 3% increase in scores for fatigue compared with test-negative participants (score ratio [SR] 1.0; 95% confidence interval [CI], 1.03 to 1.04). The test-positive participants also had higher odds of self-reported postexertional malaise (odds ratio, 2.04; 95% CI, 1.81 to 2.30).

Hospitalization linked to more fatigue 

Participants who were hospitalized with COVID-19 had increased fatigue scores by 23% (SR, 1.23; 95% CI, 1.20 to 1.26) compared with test-negative participants. 

Of the possible predisposing factors explored, acute SARS-CoV-2 hospitalization had the greatest impact on fatigue scores

"Of the possible predisposing factors explored, acute SARS-CoV-2 hospitalization had the greatest impact on fatigue scores," the authors concluded. Contrary to other findings, the authors said their study did not show a link between preexisting psychiatric conditions and long COVID fatigue.

"We observed a greater risk of PCC [post–COVID-19 condition] fatigue symptoms among individuals who tested positive during the Alpha wave, when most were not yet vaccinated," the authors concluded. "Persons who had received no or only 1 vaccine dose before testing had higher SRs across several follow-up points, compared with persons who had received 2 or 3 doses."

The effectiveness of the long-acting monoclonal antibody nirsevimab (Beyfortus) against primary care visits for lower respiratory tract infections (LRTIs) caused by the respiratory syncytial virus (RSV) was 76% in 160 infants younger than 10 months old from November 2023 to February 2024, researchers in Murcia and Valencia, Spain, reported late last week in Pediatrics.

In September 2023, the Spanish national immunization program targeted three groups at high risk for severe RSV based on their birth date and underlying conditions: those born during the vaccination campaign (seasonal group), those younger than 6 months at the start of the campaign (catch-up group), and those aged 6 to 24 months with high-risk conditions at the campaign start.

RSV is the main cause of LRTIs in children younger than 5 years, the authors noted. 

Role of catch-up vaccination

Investigators with the MEDiterranean Infectious diseases PRIMary care (MEDIPRIM) network of primary care centers used a test-negative study design to estimate the effectiveness of nirsevimab against medically attended RSV-LRTIs among all infants born after April 1, 2023. In total, 141 babies (88%) received the drug, 29 of them at birth and 112 through the catch-up program.

This study underscores the effectiveness of nirsevimab in preventing medically attended LRTI in infants in outpatient settings and emphasizes the importance of a catch-up immunization program to reduce the disease burden in primary care.

Forty-four infants overall (27.5%) tested positive for RSV, and 116 served as controls. Three-quarters (75%) of infected infants had been vaccinated against RSV, as were 93% of controls. Seven children were hospitalized, three of whom were 3 months or older. Of those children, three tested positive for RSV and were younger than 3 months old; two of the three had been vaccinated, as was one control. 

The estimated effectiveness of the RSV vaccine was 75.8% (95% credible interval [CI], 40.4% to 92.7%) overall and 80.2% (95% CI, 44.3% to 95.4%) in infants in the catch-up group.

"This study underscores the effectiveness of nirsevimab in preventing medically attended LRTI in infants in outpatient settings and emphasizes the importance of a catch-up immunization program to reduce the disease burden in primary care," the researchers wrote.