Covid Science: Antibodies in children last at least 6 mos after COVID; SK Bioscience vaccine shows promise vs Omicron (updated)

SK Bioscience Co

22/03/2022 15:07

(Adds background detail on another study to first item)
    By Nancy Lapid
    March 21 (Reuters) - The following is a summary of some
recent studies on COVID-19. They include research that warrants
further study to corroborate the findings and that has yet to be
certified by peer review.

    Antibodies in kids after COVID last 6 months or more
    Most children and adolescents with COVID-19 antibodies after
SARS-CoV-2 infection usually still have the antibodies in their
blood more than half a year later, new data shows.
    Starting in October 2020, researchers in Texas recruited 218
subjects between the ages of 5 and 19. Each provided three blood
samples, at three-month intervals. More than 90% were
unvaccinated when they enrolled in the study. The first blood
test showed infection-related antibodies indicating recovery
from COVID-19 in one-third of the children, the researchers
reported online Friday in Pediatrics https://publications.aap.org/pediatrics/article/doi/10.1542/peds.2021-055505/185412/Durability-of-SARS-CoV-2-Antibodies-From-Natural.
 Six months later, 96% of those with the antibodies still had
them. The study was designed to detect the presence of
antibodies, which are only one component of the immune system's
defenses, not the amount of antibodies. The level of protection
even in those with antibodies is unclear. Researchers found no
differences based on whether a child was asymptomatic, severity
of symptoms, when they had the virus or due to weight or gender.
    "It was the same for everyone," Sarah Messiah of UTHealth
School of Public Health Dallas, said in a statement. "Some
parents... think just because their child has had COVID-19, they
are now protected and don't need to get the vaccine," Messiah
said. "We have a great tool available to give children
additional protection by getting their vaccine."
    A small study published earlier this month in JAMA Network
Open https://jamanetwork.com/journals/jamanetworkopen/fullarticle/2789845
 suggested that most children infected with the coronavirus do
not have antibodies in their blood afterward. Only 37% of
children appeared to develop antibodies, compared to 76% of
adults, even though viral loads were similar in the two groups,
those researchers found. 
    
    Experimental SK vaccine shows promise against Omicron
    A booster shot of an experimental vaccine being developed by
SK Bioscience Co  302440.KS  has shown "durable protection"
against the Omicron variant in Rhesus macaques, according to new
data.
    The monkeys had received two initial doses of the vaccine
plus a booster 6 or 12 months later. Blood samples from the
boosted primates showed "remarkably high" levels of antibodies
that could neutralize both the original strain of the virus and
the Omicron variant that caused infections to soar, the
researchers reported on Sunday on bioRxiv https://www.biorxiv.org/content/10.1101/2022.03.18.484950v1
 ahead of peer review. The animals' second-line immune defenses
were also "substantial and persistent," they said. The vaccine,
called GBP510, triggers responses from the immune system by
delivering copies of a key part of the spike protein from the
surface of the coronavirus. The protein "subunits" are studded
onto nanoparticles to resemble the virus itself. These
components are supplemented with an adjuvant from GSK  GSK.L 
that boosts the immune system's responses, explained Bali
Pulendran of Stanford University in California.
    "Vaccination with two doses... followed a year later by a
booster shot... plus adjuvant, led to highly durable antibody
responses and protection against Omicron infection, even six
months later," Pulendran said. Large late-stage trials of GBP510
in humans are underway. 
    
    AstraZeneca drug less protective vs Omicron in transplant
patients
    The AstraZeneca  AZN.L  antibody shots given to prevent
COVID-19 in high-risk children and adults with weakened immune
systems do not adequately protect organ transplant recipients
from the Omicron variant, researchers found.
    The drug, Evusheld, did protect against the Delta variant in
kidney transplant recipients, and lab test results released on
Monday show Evusheld can neutralize Omicron in mice, including
the highly contagious BA.2 version. But among 416 kidney
recipients treated with Evusheld after Omicron became the
predominant variant, 9.4% developed symptomatic breakthrough
infections, with one-in-three of those patients requiring
hospitalization, researchers reported on Saturday on medRxiv https://www.medrxiv.org/content/10.1101/2022.03.19.22272575v1
 ahead of peer review. Two patients died of COVID-19. In lab
experiments, the researchers exposed the BA.1 version of Omicron
that caused the massive winter surge to blood samples from 15
Evusheld-treated patients. None of the samples could neutralize
the virus.
    The U.S. Food and Drug Administration recently advised https://www.fda.gov/drugs/drug-safety-and-availability/fda-authorizes-revisions-evusheld-dosing
 that higher doses of Evusheld are likely needed to prevent
Omicron infections, and that patients who received the
originally approved shots should receive booster doses. The
researchers said kidney transplant recipients "should be advised
to maintain sanitary protection measures and undergo vaccine
boosters." 
    
    Click for a Reuters graphic https://tmsnrt.rs/3c7R3Bl on
vaccines in development.

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Tracking the vaccine race    http://graphics.reuters.com/HEALTH-CORONAVIRUS/VACCINE-TRACKER/xegpbqnlovq/
COVID-19 vaccination tracker    https://graphics.reuters.com/world-coronavirus-tracker-and-maps/vaccination-rollout-and-access/
S.Korea to buy 10 million doses of SK Bioscience's COVID vaccine
    urn:newsml:reuters.com:*:nL2N2VO07I
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 (Reporting by Nancy Lapid; Editing by Bill Berkrot)
 ((Nancy.Lapid@thomsonreuters.com))