Coronavirus COVID-19 Update for October 22, 2021

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Clinical Reports

Effect of Antithrombotic Therapy on Clinical Outcomes in Outpatients With Clinically Stable Symptomatic COVID-19
Among symptomatic but clinically stable outpatients with COVID-19, does adding antithrombotic therapy, compared with placebo, reduce major cardiopulmonary adverse outcomes over a 45-day treatment period? This randomized trial of 657 symptomatic outpatients with COVID-19 conducted in the US was stopped early because of an unanticipated low event rate. Among randomized participants who initiated trial treatment with aspirin (81 mg once daily), apixaban (2.5 mg twice daily), apixaban (5.0 mg twice daily), or placebo, the rates of an adjudicated composite outcome (all-cause mortality, symptomatic venous or arterial thromboembolism, myocardial infarction, stroke, or hospitalization for cardiovascular or pulmonary cause) after 45 days were 0.0%, 0.7%, 1.4%, and 0.0%, respectively; there were no significant differences between the active groups and the placebo group. These data do not support the use of aspirin or apixaban in the outpatient setting to reduce the major adverse cardiovascular or pulmonary consequences associated with symptomatic but clinically stable SARS-CoV-2 infection.
Association of Serum Ferritin Levels and Methylprednisolone Treatment With Outcomes in Nonintubated Patients With Severe COVID-19 Pneumonia
In this cohort study including 380 nonintubated patients with severe COVID-19 pneumonia, methylprednisolone was associated with lower mortality and reduced rates of death or mechanical ventilation only in patients with admission ferritin levels in the upper tertile of values (1322-13418 ng/mL); in contrast, there was no association with benefit among those with lower ferritin values at baseline. These findings suggest that ferritin levels on admission may be used as a marker associated with corticosteroid response among patients with severe COVID-19 pneumonia.
Efficacy and Safety of Therapeutic-Dose Heparin vs Standard Prophylactic or Intermediate-Dose Heparins for Thromboprophylaxis in High-risk Hospitalized Patients With COVID-19
Does thromboprophylaxis with therapeutic-dose low-molecular-weight heparin reduce the incidence of major thromboembolism and death compared with prophylactic/intermediate-dose heparins in inpatients with high-risk COVID-19? In this randomized clinical trial of 253 adults, the incidence of major thromboembolism or death was 28.7% with therapeutic-dose vs 41.9% with prophylactic/intermediate-dose heparins, a significant difference—driven by reduction in thromboembolism—that was not seen in critically ill patients. There was no significant difference in major bleeding between groups. Thromboprophylaxis with therapeutic-dose low-molecular-weight heparin reduces a composite outcome of major thromboembolism and death in high-risk inpatients with COVID-19.

Antiviral Therapeutics and Vaccines

Comprehensive antibody profiling of mRNA vaccination in children
With the emergence of SARS-CoV-2 variants, fluctuating mask mandates, and school re-openings, increased infections and disease surged among children recently. Thus, there is an urgent need for COVID-19 vaccines for children of all ages. However, whether young children will respond appropriately to mRNA vaccines remains unclear. Authors deeply profiled the vaccine-induced humoral immune response in 7-11 year old children receiving the mRNA-1273 vaccine. Vaccinated children induced significantly higher antibody titers and functions compared to naturally infected children. Moreover, comparable SARS-CoV-2 titers and neutralizing activity across variants of concern and superior Fcγ-receptor binding and phagocytic antibodies were observed in children compared to vaccinated adults. Our data indicate that mRNA vaccination elicits robust antibody responses and drives superior antibody functionality in children.
Evaluation of a SARS-CoV-2 Vaccine NVX-CoV2373 in Younger and Older Adults
NVX-CoV2373 is a recombinant severe acute respiratory coronavirus 2 (rSARS-CoV-2) nanoparticle vaccine composed of trimeric full-length SARS-CoV-2 spike glycoproteins and Matrix-M1 adjuvant. The phase 2 component of a randomized, placebo-controlled, phase 1-2 trial was designed to identify which dosing regimen of NVX-CoV2373 should move forward into late phase studies in younger (18-59 years) and older (60-84 years) participants and was based on immunogenicity and safety data through day 35 (14 days after the second dose). Participants were randomly assigned to receive either one or two intramuscular doses of 5-µg or 25-µg NVX-CoV2373 or placebo, 21 days apart. Primary endpoints were immunoglobulin G (IgG) anti-spike protein response, 7-day solicited reactogenicity, and unsolicited adverse events. A key secondary endpoint was wild-type virus neutralizing antibody response. After randomization, approximately 250 participants each were assigned to one of four vaccine groups or placebo. Of these, approximately 45% were older participants. Reactogenicity was predominantly mild to moderate in severity and of short duration (median <3 days) after first and second vaccination with NVX-CoV2373, with higher frequencies and intensity after second vaccination and with the higher dose, and occurred less frequently and was of lower intensity in older participants. The two-dose regimen of 5-µg NVX-CoV2373 induced robust geometric mean titer (GMT) IgG anti-spike protein (65,019 and 28,137 EU/mL) and wild-type virus neutralizing antibody (2201 and 981 titers) responses in younger and older participants, respectively, with seroconversion rates of 100% in both age groups. Neutralizing antibody responses exceeded those seen in convalescent sera for both age groups. The study confirmed that the two-dose regimen of 5-µg NVX-CoV2373 is highly immunogenic and well tolerated in both younger and older participants.
Heterologous SARS-CoV-2 Booster Vaccinations – Preliminary Report
While Coronavirus disease 2019 (Covid-19) vaccines are highly effective, breakthrough infections are occurring. Booster vaccinations have recently received emergency use authorization (EUA) for certain populations but are restricted to homologous mRNA vaccines. Authors evaluated homologous and heterologous booster vaccination in persons who had received an EUA Covid-19 vaccine regimen. In this phase 1/2 open-label clinical trial conducted at ten U.S. sites, adults who received one of three EUA Covid-19 vaccines at least 12 weeks prior to enrollment and had no reported history of SARS-CoV-2 infection received a booster injection with one of three vaccines (Moderna mRNA-1273 100-μg, Janssen Ad26.COV2.S 5×10¹⁰ virus particles, or Pfizer-BioNTech BNT162b2 30-μg; nine combinations). The primary outcomes were safety, reactogenicity, and humoral immunogenicity on study days 15 and 29. 458 individuals were enrolled: 154 received mRNA-1273, 150 received Ad26.CoV2.S, and 154 received BNT162b2 booster vaccines. Reactogenicity was similar to that reported for the primary series. Injection site pain, malaise, headache, and myalgia occurred in more than half the participants. Booster vaccines increased the neutralizing activity against a D614G pseudovirus (4.2-76-fold) and binding antibody titers (4.6-56-fold) for all combinations; homologous boost increased neutralizing antibody titers 4.2-20-fold whereas heterologous boost increased titers 6.2-76-fold. Day 15 neutralizing and binding antibody titers varied by 28.7-fold and 20.9-fold, respectively, across the nine prime-boost combinations. Homologous and heterologous booster vaccinations were well-tolerated and immunogenic in adults who completed a primary Covid-19 vaccine regimen at least 12 weeks earlier.
FDA to Hold Advisory Committee Meeting to Discuss Merck and Ridgeback’s EUA Application for COVID-19 Oral Treatment
The U.S. Food and Drug Administration is announcing an upcoming meeting of its Antimicrobial Drugs Advisory Committee (AMDAC) to discuss Merck and Ridgeback’s request for an emergency use authorization (EUA) for molnupiravir, an investigational antiviral drug to treat COVID-19. On Nov. 30, the advisory committee will meet to discuss the available data supporting the use of molnupiravir to treat mild-to-moderate coronavirus disease 2019 (COVID-19) in adults who have tested positive for COVID-19, and who are at high risk for progression to severe COVID-19, including hospitalization or death.
AZD7442 reduced risk of developing severe COVID-19 or death in TACKLE Phase III outpatient treatment trial
Positive high-level results from the TACKLE Phase III COVID-19 treatment trial showed AstraZeneca's AZD7442, a long acting antibody (LAAB) combination, achieved a statistically significant reduction in severe COVID-19 or death compared to placebo in non-hospitalised patients with mild-to-moderate symptomatic COVID-19. A total of 90% of participants enrolled were from populations at high risk of progression to severe COVID-19, including those with co-morbidities. The trial met the primary endpoint, with a dose of 600mg of AZD7442 given by intramuscular (IM) injection reducing the risk of developing severe COVID-19 or death (from any cause) by 50% compared to placebo in outpatients who had been symptomatic for seven days or less. The trial recorded 18 events in the AZD7442 arm (18/407) and 37 in the placebo arm (37/415). The LAAB was generally well tolerated in the trial. In a prespecified analysis of participants who received treatment within five days of symptom onset, AZD7442 reduced the risk of developing severe COVID-19 or death (from any cause) by 67% compared to placebo, with nine events in the AZD7442 arm (9/253) and 27 in the placebo arm (27/251). AZD7442 is the first LAAB with Phase III data to demonstrate benefit in both prophylaxis and treatment of COVID-19 and is easily administered by IM injection.
WHO, UN set out steps to meet world COVID vaccination targets
The World Health Organization has today launched the Strategy to Achieve Global Covid-19 Vaccination by mid-2022 (the Strategy) to help bring an end to what has become a two-track pandemic: people in poorer countries continue to be at risk while those in richer countries with high vaccination rates enjoy much greater protection. WHO had set a target to vaccinate 10% of every country, economy and territory by the end of September but by that date 56 countries had not been able to do so, the vast majority of these are countries in Africa and the Middle East. The new strategy outlines a plan for achieving WHO’s targets to vaccinate 40% of the population of every country by the end of this year and 70% by mid-2022.
Coronavirus (COVID-19) Update: FDA Authorizes Additional Vaccine Dose for Certain Immunocompromised Individuals
The U.S. Food and Drug Administration amended the emergency use authorizations (EUAs) for both the Pfizer-BioNTech COVID-19 Vaccine and the Moderna COVID-19 Vaccine to allow for the use of an additional dose in certain immunocompromised individuals, specifically, solid organ transplant recipients or those who are diagnosed with conditions that are considered to have an equivalent level of immunocompromise. The Centers for Disease Control and Prevention’s Advisory Committee on Immunization Practices is scheduled to meet to discuss further clinical recommendations regarding immunocompromised individuals. Today’s action does not apply to people who are not immunocompromised.