In a randomized, double-blind, placebo-controlled phase 3 trial of the ChAdOx1 nCoV-19 vaccine in over 32,000 participants from the United States, Chile, and Peru, the incidence of serious adverse ...effects was low (including no cases of vaccine-induced immune thrombotic thrombocytopenia) and the vaccine efficacy was 74%. Efficacy was documented in a range of demographic subgroups.
In the coronavirus efficacy (COVE) phase 3 clinical trial, vaccine recipients were assessed for neutralizing and binding antibodies as correlates of risk for COVID-19 disease and as correlates of ...protection. These immune markers were measured at the time of second vaccination and 4 weeks later, with values reported in standardized World Health Organization international units. All markers were inversely associated with COVID-19 risk and directly associated with vaccine efficacy. Vaccine recipients with postvaccination 50% neutralization titers 10, 100, and 1000 had estimated vaccine efficacies of 78% (95% confidence interval, 54 to 89%), 91% (87 to 94%), and 96% (94 to 98%), respectively. These results help define immune marker correlates of protection and may guide approval decisions for messenger RNA (mRNA) COVID-19 vaccines and other COVID-19 vaccines.
The randomized trial assessing the efficacy of a single injection of the Ad26.COV2.S showed 56.3% vaccine efficacy beginning 14 days after injection and 52.9% efficacy more than 28 days after ...injection against moderate to severe–critical Covid-19. Protection lasted at least 6 months without an added boost. Vaccination was associated with mild-to-moderate adverse effects.
In a recent study, a 20-valent mRNA vaccine elicited immunity against influenza virus in mice. These results, combined with the success of mRNA vaccines against Covid-19, augur well for a new type of ...influenza vaccine.
Even in years with modest-to-high vaccine effectiveness, populations at high risk for influenza-related morbidity and mortality, such as the frail elderly and people of all ages with ...immunocompromising conditions, do not respond optimally to vaccines. ...identification of potent antiviral drugs is needed for the prevention and treatment of influenza infection, and particularly for the treatment of severe disease. Antiviral drugs that target and block the activity of these subunits include: baloxavir marboxil, which targets the polymerase acidic protein component;5 pimodivir (VX-787), which targets PB2; and a nucleoside analogue, favipiravir (T-705), which targets PB1.6 Of note, clinical development of pimodivir was discontinued in 2020 as it did not show benefit over the standard of care, leaving a gap in the clinical availability of PB2 inhibitors. Encouraging results from observational studies have suggested that antiviral treatment of influenza can have clinical benefit in patients with severe, complicated, or progressive illness, and in patients treated in hospital after 48 h of illness onset.9 Finally, although the current study was predominantly in healthy young adults, these results need to be replicated in a population at higher risk for influenza infection, including older adults, those with immunosuppression, and those with chronic medical conditions.
Participants who had been fully vaccinated with current Covid-19 vaccines received homologous or heterologous boosters, and their immune response was measured on days 15 and 29. Homologous boosters ...increased neutralizing antibody titers by a factor of 4 to 20, whereas heterologous boosters increased titers by a factor of 6 to 73.
The efficacy of a Vi polysaccharide typhoid conjugate vaccine (Vi-TCV) was assessed in 28,130 Malawian children who were 9 months to 12 years of age. The incidence of blood culture–confirmed typhoid ...fever was significantly lower among children who received Vi-TCV than among those who received a control vaccine.
Background. Pneumonia is recognized as a leading cause of morbidity in seniors. However, the overall burden of this disease—and, in particular, the contribution of ambulatory cases to that burden—is ...not well defined. To estimate rates of community-acquired pneumonia and to identify risk factors for this disease, we conducted a large, population-based cohort study of persons aged ⩾65 years that included both hospitalizations and outpatient visits for pneumonia. Methods. The study population consisted of 46,237 seniors enrolled at Group Health Cooperative who were observed over a 3-year period. Pneumonia episodes presumptively identified by International Classification of Diseases, Ninth Revision, Clinical Modification codes assigned to medical encounters were validated by medical record review. Characteristics of participants were defined by administrative data sources. Results. The overall rate of community-acquired pneumonia ranged from 18.2 cases per 1000 person-years among persons aged 65–69 years to 52.3 cases per 1000 person-years among those aged ⩾85 years. In this population, 59.3% of all pneumonia episodes were treated on an outpatient basis. In multivariate analysis, risk factors for community-acquired pneumonia included age, male sex, chronic obstructive pulmonary disease, asthma, diabetes mellitus, congestive heart failure, and smoking. Conclusions. On the basis of these data, we estimate that roughly 915,900 cases of community-acquired pneumonia occur annually among seniors in the United States and that ∼1 of every 20 persons aged ⩾85 years will have a new episode of community-acquired pneumonia each year.
Controlled human infection models have been proposed as a strategy for accelerating SARS-CoV-2 vaccine development. But scientific and technical factors make CHIMs unlikely to accelerate the ...establishment of vaccine efficacy.
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