Billions of doses of COVID-19 vaccines have been administered globally, dramatically reducing SARS-CoV-2 incidence and severity in some settings. Many studies suggest vaccines provide a high degree of protection against infection and disease, but precise estimates vary and studies differ in design, outcomes measured, dosing regime, location, and circulating virus strains. Here we conduct a systematic review of COVID-19 vaccines through February 2022. We included efficacy data from Phase 3 clinical trials for 15 vaccines undergoing WHO Emergency Use Listing evaluation and real-world effectiveness for 8 vaccines with observational studies meeting inclusion criteria. Vaccine metrics collected include protection against asymptomatic infection, any infection, symptomatic COVID-19, and severe outcomes including hospitalization and death, for partial or complete vaccination, and against variants of concern Alpha, Beta, Gamma, Delta, and Omicron. We additionally review the epidemiological principles behind the design and interpretation of vaccine efficacy and effectiveness studies, including important sources of heterogeneity.
Billions of doses of COVID-19 vaccines have been administered around the world, dramatically reducing SARS-CoV-2 incidence in some settings. Many studies suggest vaccines provide a high degree of protection against infection and disease, but precise estimates vary and studies differ in design, outcomes measured, dosing regime, location, and circulating virus strains. Here we conduct a systematic review of COVID-19 vaccines as of August 2021. We included efficacy data from Phase 3 clinical trials for 13 vaccines within the WHO Emergency Use Listing evaluation process and real-world effectiveness for 5 vaccines with observational studies meeting inclusion criteria. Vaccine metrics collected include effects against asymptomatic infection, any infection, symptomatic COVID-19, and severe outcomes including hospitalization and death, for both partial and complete vaccination, and against SARS-CoV-2 variants of concern. In addition, we review the epidemiological principles behind the design and interpretation of vaccine effects, and explain important sources of heterogeneity between studies.
We devised a new flap using the palmar cutaneous branch of the superficial radial artery proximally and anastomosed with a cutaneous perforator of the superficial palmar arch distally. We named our flap "the volar glabrous palmar flap." The flap was used both as a free flap and as a reverse-flow island flap. Thirty-six patients with volar hand defects (24 digits, 7 palms, and 5 first web space) were reconstructed with this flap. The flap was used as a proximally based free flap in 15 patients and was used as a reverse-flow island flap based on distal communication in the remaining 21 patients. Free flaps were supplied by the palmar branch of the superficial radial artery and its fasciocutaneous extensions; reverse-flow island flaps were supplied by one of the perforating branches of the superficial palmar arch, which is connected to the proximal fasciocutaneous branches. Flaps extended from the wrist crease to the proximal palmar crease and were designed medially on the thenar crease, extending 2 to 2.5 cm laterally. Flap sizes ranged from 1.5 x 2.2 cm to 2.5 x 10 cm. The palmar cutaneous branch of the median nerve within the flap area was identified and then was sutured to the divided digital nerve in 6 cases of finger pulp defect. The donor sites were closed and repaired primarily in most cases. The postoperative course was uneventful, and all the flaps survived without major complications. Follow-up (minimum 6 mo, mean 24 mo) showed excellent functional and cosmetic results. Satisfactory sensory reinnervation was achieved in patients who underwent sensory flap transfer for pulp defects. At the same time, we studied 6 cadaver hands to understand the vascular anatomy of the thenar area of the hand. We also revised several published anatomic papers to obtain a refined and scrutinized understanding of the palmar anatomy.
Nutritional status in pregnancy is a key determinant of birth outcomes. In low-income countries, maternal diets are often limited, and daily nutrient supplements are recommended to fill nutrient gaps. As a result, it is important to understand the factors influencing acceptability and utilization of nutrient supplements in these settings. Qualitative data (individual interviews and focus group discussions with pregnant women, household members, and study staff) and quantitative data (unannounced household spot checks) were collected in 24 villages in the Maradi region of south-central Niger. Each village was randomly assigned to one of three study arms, with pregnant women receiving either iron and folic acid (IFA) supplements, multiple micronutrient (MMN) supplements, or medium-quantity lipid-based nutrient supplements (MQ-LNS) for daily consumption during pregnancy. Data were collected longitudinally to capture changes in perspective as women progressed through their pregnancy. Participants accepted all three supplement types, and perceived a wide range of health benefits attributed to supplement consumption. However, several important barriers to appropriate consumption were reported, and rumors about the supplements leading to childbirth complications also decreased utilization. The household spot checks suggested that IFA had the highest level of correct consumption. Overall, despite a stated high level of acceptance and enthusiasm for the supplements among participants and their household members, certain fears, side effects, and organoleptic factors led to decreased utilization. The effectiveness of future programs to improve maternal nutritional status through supplementation may be improved by understanding perceived barriers and facilitating factors among participants and tailoring communication efforts appropriately.
Undernutrition is associated with maternal morbidity and poor pregnancy outcomes. This qualitative study seeks to understand the multilevel factors influencing maternal dietary practices in Niger, including the impact of pregnancy illnesses on diet. Criterion‐based, purposive sampling was used to select pregnant women and household members from 24 villages in a rural district of the Maradi Region in south‐central Niger. Semistructured interviews (n = 153) and focus group discussions (n = 38) explored 4 primary themes: (a) perceptions of ideal diet during pregnancy, (b) barriers to consuming the ideal diet, (c) coping strategies including dietary responses related to pregnancy illnesses, and (d) changes in perceptions from early to late pregnancy. Longitudinal data collection allowed for repeated interviews of pregnant women to document changes in dietary practices throughout pregnancy. Transcripts were coded using an inductive approach informed by grounded theory methodology. Participants categorized foods into 4 primary dietary taxonomies when discussing ideal maternal diets but cited constraints related to accessibility and availability impeding routine consumption of these foods. Perceptions of “modern,” urban foods as healthy, coupled with key structural barriers such as food costs, were identified. Maternal morbidity influenced food consumption, as women reported reducing food intake early in pregnancy in response to illness episodes. Although awareness of optimal foods for supporting healthy pregnancies was moderately high, some misconceptions were observed and multilevel barriers to food security restricted opportunities for consuming these foods. Nutrition‐specific and nutrition‐sensitive interventions could improve access and availability of acceptable foods for supporting increased dietary intake during pregnancy.
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