COVID shots, previous infection may cut risk of spread in prisons

News brief

Recent COVID-19 vaccination and previous infections independently lowered the odds of Omicron variant transmission from infected California prison inmates to their cellmates, but the risk remained high, suggests a study published earlier this week in Nature Medicine.

University of California at San Francisco (UCSF) researchers led the study of 111,687 inmates in 35 prisons populated mostly by men (97%) from Dec 15, 2021, to May 20, 2022. The California Department of Corrections and Rehabilitation supplied the data.

Despite 81% uptake of the primary COVID-19 vaccine series, breakthrough infections were common. The rate of severe disease was low, however; of the 22,334 inmates tested positive, 31 were hospitalized, and none died.

Unvaccinated, infected inmates had an estimated 36% risk of spreading the virus, compared with 28% among infected vaccinees. After adjustment, any vaccination, previous infection alone, and both vaccination and previous infection cut the risk of SARS-CoV-2 transmission by 22%, 23%, and 40%, respectively.

Booster doses and more recent vaccination further lowered infectiousness among vaccinated inmates, with each dose conferring an 11% risk reduction; the risk of transmission rose 6% for every 5 weeks that had elapsed since the last shot.

Vaccinating more inmates, staff

"A lot of the benefits of vaccines to reduce infectiousness were from people who had received boosters and people who had been recently vaccinated," senior author Nathan Lo, MD, PhD, said in a UCSF news release. "Our findings are particularly relevant to improving health for the incarcerated population."  

A lot of the benefits of vaccines to reduce infectiousness were from people who had received boosters and people who had been recently vaccinated.

The researchers urged prisons to keep inmates up to date with boosters, as only 59% of inmates and 41% of staff had done so, and to increase vaccination among staff, as only 73% of them had completed the primary series.

"Within the two months following vaccination, people are the least infectious, which indicates that boosters and large timed vaccination campaigns may have a role to reduce transmission in surges," Lo said. "New ideas are needed, since the risk of infection in this vulnerable population remains so great."

Certain symptoms diminish well-being in long-COVID patients, survey shows

News brief

Among long-COVID patients in Israel, nonspecific emotional and cognitive symptoms such as fatigue, lack of concentration, and sleep disorders lowered subjective well-being (SWB) the most, according to a study published today in Epidemiology & Infection.

As part of an ongoing study, a team led by Bar Ilan University researchers analyzed the results of an online symptom survey sent to 2,295 participants, 576 of whom had tested positive for COVID 3 to 6, 6 to 12, and 12 to 18 months earlier, from July 2021 to April 2022. A total of 92% of participants were vaccinated, and the uninfected patients (75%) were used as controls. Among the previously infected, 68% reported at least one ongoing COVID-19 symptom.

Symptom effects evolved over time

Overall, the SWB scores of previously infected patients reporting no lingering symptoms were comparable to those of the never-infected (74.3 vs 73.7 on a 100-point scale). Symptomatic participants were more likely to be female than male, and vaccinees reported fewer symptoms.

The most common symptoms were fatigue (42%), muscle weakness (26%), muscle pain (23%), confusion/lack of concentration (22%), and sleep disorders (21%).

Nonspecific symptoms had the most negative impact on SWB, with declines of 7.7 percentage points for fatigue, 10.7 percentage points for confusion or lack of concentration, and 11.5 percentage points for sleep disorders. Specific symptoms (eg, muscle pain and weakness) had less pronounced and more transient effects.

Individual symptoms affected SWB differently over time. For example, patients reporting fatigue at 3 to 6 months showed a nonsignificant 8.1 percentage-point decrease in SWB, but those reporting it at 12 to 18 months showed a significant drop of 12.6 percentage points. Such differences, the authors said, could reflect changes in disease severity or adaptation to physical symptoms over time.

"Taking a similar approach for other symptoms and following individuals over time to describe trends in SWB changes attributable to specific symptoms will help understand the post-acute phase of COVID-19 and how it should be defined and better managed," they wrote.

The most common symptoms were fatigue (42%), muscle weakness (26%), muscle pain (23%), confusion/lack of concentration (22%), and sleep disorders (21%).

WHO: Yellow fever cases in Africa decline, but challenges remain

News brief

In an update yesterday on yellow fever in Africa, the World Health Organization (WHO) said 12 countries reported cases in 2022, including 8 that also had transmission in 2021. Since 2021, 203 confirmed and 252 probable cases were reported, 40 of them fatal.

The case-fatality rate among the confirmed cases was high, at 11% and 12% for 2021 and 2022, respectively.

Countries reporting cases for both years were Cameroon, the Central African Republic, Chad, Ivory Coast, the Democratic Republic of the Congo, Ghana, Nigeria, and the Republic of the Congo. For 2022, newly reporting countries were Kenya, Niger, Sierra Leone, and Uganda.

Also, Gabon reported one isolated confirmed cases in 2021, but didn't report any in 2022.

Young kids hit hardest

Overall, about 71% of the confirmed cases were in people younger than 30, with kids age 10 years and younger disproportionately affected. Since Aug 26, there have been only 7 newly confirmed cases, 1 of them fatal.

Ongoing vaccination campaigns that reached more than 4 million people starting in 2021 have boosted coverage in targeted countries and may have lessened transmission in 2022, though the WHO added the caveat that variations in transmission dynamics are difficult to predict.

On Dec 12, the WHO reassessed the risk, dialing back the threat from high to moderate owing to the decline in reported cases and increasing population immunity. It added, however, that there are still a number of challenges, including ongoing circulation in some high-risk areas and the detection of recent cases in urban areas, such as in Cameroon and Uganda, where there is little or no underlying immunity.

The WHO said the overall global risk is low, but it warned that ecosystems are favorable for the spread of yellow fever in other parts of the world, especially in neighboring countries in the WHO Eastern Mediterranean region.

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