Study suggests 3 Pfizer vaccine doses may protect against Omicron
Today a study from Germany published in Science shows three doses of the Pfizer-BioNTech COVID-19 vaccine raised antibody levels against the highly transmissible Omicron (B.1.1.529) variant.
The study was based on sera from 51 participants, which was challenged with Wuhan, Beta, Delta, or Omicron pseudoviruses. The participants had received either two or three doses of the Pfizer vaccine. Though neutralizing antibodies are just one measure of vaccine effect and don't demonstrate effectiveness per se, the authors say they can be strongly predictive of the degree of immune protection against symptomatic SARS-CoV-2 infection.
Twenty-one days after the primary two-dose series, sera samples had a significant reduction in neutralizing activity against Omicron; after two doses, geometric mean neutralization titers (GMT) against Omicron pseudovirus were 22.8-fold lower than the Wuhan reference pseudovirus, and 20 out of 32 immune sera displayed no detectable neutralizing activity against Omicron.
But within 4 weeks of a third dose, Omicron-neutralizing titers had increased 23-fold compared with two doses.
"Our data show that a third BNT162b2 [Pfizer] dose effectively neutralizes Omicron at a similar order of magnitude as was observed after two doses of BNT162b2 against wild-type SARS-CoV-2," the authors concluded.
Jan 18 Science study
Fewer racial minorities given monoclonal antibodies to treat COVID-19
Analysis of data from 41 healthcare systems participating in the US National Patient-Centered Clinical Research Network shows that monoclonal antibodies (mAbs) were administered to Black, Asian, Hispanic, and other minority-race COVID-19 outpatients at lower rates than their White peers.
Led by Centers for Disease Control and Prevention (CDC) researchers, the study found smaller racial differences in the use of the antiviral remdesivir and the corticosteroid dexamethasone in hospitalized COVID-19 patients. The data, collected from March 2020 to August 2021, was published late last week in Morbidity and Mortality Weekly Report (MMWR).
Among the 805,276 COVID-19 patients who received mAbs, their use was infrequent, with average monthly use of 4% or less for all racial groups. Hispanic patients were given mAbs 58% less often than other patients, and Black and Asian patients and those of other races were given the antibodies 22%, 48%, and 47% less often, respectively, than their White counterparts from November 2020 to August 2021.
Of the 120,204 inpatients who received remdesivir and dexamethasone, Hispanic patients were given dexamethasone 6% less often than others, and Black patients received remdesivir 9% more often than White patients.
"This could indicate racial and ethnic differences in clinical indications for medication use (e.g., age distribution and prevalence of comorbidities) or could be reflective of varying prescribing practices, protocols, and drug access by institutions that serve populations of different racial and ethnic distributions," the researchers said.
Reducing racial inequities in access to COVID-19 therapies requires patient and clinician awareness of the problem and potential solutions; resources; and action by government, private entities, and community- and faith-based organizations, the researchers said.
"Bringing health care to populations facing barriers in access to mAb via a mobile infusion unit or via telehealth providers has been shown to increase mAb use, decrease severe outcomes, and reduce costs," they wrote. "Efforts to reduce racial and ethnic disparities with equitable outpatient COVID-19 treatment access, practices, and supportive systems are urgently needed."
The authors emphasized that while mAbs, remdesivir, and dexamethasone can reduce COVID-19–related illness and death and relieve the hospital burdens, vaccines and other preventive measures remain the best defenses against infection.
Jan 14 MMWR study