People with Down syndrome at higher risk for severe COVID-19
The Journal of Infectious Diseases has published studies demonstrating lower COVID-19 incidence—but a higher risk of severe disease—in people with Down syndrome (DS), and a lower COVID vaccine immune response.
In the first matched cohort study, based on data collected from the Kaiser Permanente system in California, 2,541 people with DS and 10,164 without DS were matched by age, sex, and race/ethnicity. The study was conducted from Mar 1, 2020, to Dec 31, 2020, before COVID-19 vaccines were available and before SARS-CoV-2 variants were widely circulating.
People with DS were 32% less likely to contract COVID-19 than non-DS matches (adjusted hazard ratio [aHR], 0.68; 95% confidence interval [CI], 0.56 to 0.83,) but they had severe COVID-19 six times more often (aHR, 6.14; 95% CI; 1.87 to 20.16).
The authors said caregivers of those with DS likely practiced stricter COVID-19 precautions than others, accounting for the lower overall infection rates, but anatomical changes seen in people with DS—including to the cardiovascular system—may explain why the disease is more severe in that group.
Jun 24 J Infect Dis severity study
In the second study, vaccine antibody levels in Dutch DS patients were compared to matched non-DS peers. Blood samples were collected at baseline, within 28 days of first vaccination dose, and 28 days after the second vaccine dose for 318 participants, 214 of whom had DS.
The authors said the DS population produced fewer antibodies than the non-DS group, and antibody levels were negatively correlated with age in the DS group, with those over 40 showing lower antibody levels than younger adults with DS. The same drop was not seen in non-DS adults over the age of 40.
"Antibody responses after SARS-CoV-2 vaccination in adults with DS are significantly decreased compared with healthy adults. In older adults with DS the decreased antibody responses were even more pronounced, which, combined with the highest mortality rates, makes this group particularly vulnerable," the authors concluded.
"A third or early booster vaccination should be considered in all adults with DS, given their risk for severe disease after SARS-CoV-2 infection."
Jun 24 J Infect Dis vaccine study
Pfizer releases promising findings on Omicron boosters
Ahead of a Food and Drug Administration (FDA) vaccine advisory committee meeting tomorrow to discuss updated COVID-19 vaccines, Pfizer and BioNTech released promising findings on two of their booster candidates targeting the Omicron SARS-CoV-2 variant.
The vaccine candidates that include an Omicron-adapted monovalent (single-strain) vaccine given as a fourth booster dose at 30-microgram and 60-microgram doses increased neutralizing geometric titers against BA.1 13.5-fold and 19.6-fold, respectively. The bivalent (two-strain) vaccine showed an increase of 9.1-fold and 10.9-fold increase, respectively. Early lab studies showed both vaccines neutralized BA.4 and BA.5 subvariants, but lesser than for BA.1.
The proportions of BA.4 and BA.5 are increasing in the United States, with the 7-day average for new daily cases is up 9% from a week ago. Meanwhile, the Centers for Disease Control and Prevention (CDC) said on Jun 24 that 58% of the US population lives in an area with medium or high community transmission, down a bit from 61% the week before.
In international developments, the UK Health Security Agency (HAS) said on Jun 24 that BA.4 and BA.5 subvariants are now dominant in Britain, with BA.5 growing the fastest and expected to become dominant. The HSA urged people to make sure their vaccine status is up to date. Elsewhere, Pakistan is now requiring masks for domestic air travel, given a steady rise in COVID-19 cases.
Jun 25 Pfizer-BioNTech press release
FDA Vaccines and Related Biological Products Advisory Committee meeting materials
Washington Post COVID-19 tracker
Jun 24 CDC tweet
Jun 24 UK HSA update
Jun 27 Reuters story