ABSTRACT
OBJECTIVEUsing data from European prospective household studies, we systematically compared the symptom burden of the wild-type and Alpha variant infected individuals versus the Omicron BA.1 and BA.2 infected individuals across paediatric and adult age-groups. In addition, we measured the impact of COVID-19 vaccination on the Omicron symptom burden. METHODSThe household transmission studies were conducted during the wild-type and Alpha period (April 2020 to April 2021) and the early Omicron BA.1 and BA.2 dominant period (January to March 2022). All three studies used similar protocols. Households were prospectively followed from detection of the first SARS-CoV-2 index case until at least day 21 including (repeated) PCR testing, paired serology and daily symptom reporting for all household members. To avoid possible index-case ascertainment bias, we restricted analyses to secondary household cases. Age-stratified SARS-CoV-2 symptom burden was compared for wild-type/Alpha versus Omicron infections and for primary versus primary plus booster series vaccinated adult cases. FINDINGSIn total 216 secondary cases from wild-type/Alpha, and 130 from the Omicron period were included. Unvaccinated children <12 years experienced more symptoms and higher maximum and cumulative severity scores during the Omicron compared to the wild-type/Alpha period (p=0.004, p=0.011 and p=0.075, respectively). In adults, disease duration and maximum and cumulative severity scores were reduced during the Omicron period. Adjusted for age, gender and prior immunity Omicron was associated with lower odds for loss of smell or taste (Odds Ratio [OR]: 0.14; 95%CI 0.03-0.50), and higher, but non-significant odds for upper respiratory symptoms, fever and fatigue (ORs varying between 1.85-2.23). Comparing primary versus primary plus booster vaccinated adult cases during the Omicron period no differences were observed in disease severity or duration (p[≥]0.12). INTERPRETATIONIn children, the Omicron variant causes higher symptom burden compared to the wild-type/Alpha. Adults experienced a lower symptom burden possibly due to prior vaccination. A shift in most frequently reported symptoms occurred with a marked reduction in loss of smell or taste during the Omicron period. An additional effect of booster vaccination on symptom severity in infected adults compared to primary series only, could not be demonstrated.
Subject(s)
Fever , COVID-19 , FatigueABSTRACT
Objectives: Primary care urgently needs treatments for COVID-19 patients because current options are limited, while these patients account for more than 90% of the people infected with SARS-CoV-2. Methods: We evaluated a throat spray containing three Lactobacillaceae strains with broad antiviral properties in a randomized double-blind placebo-controlled trial. Seventy-eight eligible COVID-19 patients were randomized to verum (n=41) and placebo (n=37) within 96 hours of positive PCR-based SARS-CoV-2 diagnosis and per-protocol analysis was performed. Symptoms and severity were reported daily via an online diary. Combined nose-throat swabs and dried blood spots were collected at regular time points in the study. Results: The daily reported symptoms were highly variable, with no added benefit for symptom resolution in the verum group. Specific monitoring of the applied lactobacilli strains showed that they were detectable via microbiome (27%) and qPCR analysis (82%) of the verum group. Their relative abundances were also negatively correlated with the acute symptom score. At the end of the trial, a trend towards lower SARS-CoV-2 viral loads was observed for the verum group (2/30, 6.7% positive) compared to the placebo group (7/27, 26% positive) (p = 0.07). Conclusions: Despite a trend towards lower SARS-CoV-2 viral loads at the end of the trial and a negative correlation between relative abundances of the applied lactobacilli in the microbiome and acute symptoms, we did not observe a significant effect on overall symptom score for the verum group. This suggests that studies with earlier application of the spray in larger study populations are needed to further assess application potential.
Subject(s)
COVID-19ABSTRACT
Primary health care providers (PHCPs), especially general practitioners (GPs) are essential to organise health care efficiently. During the COVID-19 pandemic, they also keep the pressure off hospitals. PHCPs are assumed to be at high risk of a COVID-19 infection, as they are exposed to a large portion of the population (usually with less personal protective equipment than other frontline health care workers(HCWs)). Nevertheless, previous seroprevalence studies focussed on the general population or HCWs in hospital settings, rather than PHCPs. The aim of this study was to determine the seroprevalence of PHCPs after the first and during the second SARS-CoV-2 wave in Flanders (Belgium) and compare it to the seroprevalence in the general population (blood donors). A prospective cohort of PHCPs, mainly GPs (n=698) was screened for IgG antibodies against SARS-CoV-2 at five different time-points (June-December 2020). The dried blood spots they produced were analysed using a Luminex multiplex immunoassay. The seroprevalence of PHCPs remained stable between June and September 2020 (4.6-5.0%), but increased significantly from October to December (8.1-13.4%) 2020. The seroprevalence of PHCPs was not significantly higher than the seroprevalence of the blood donors at the end of December 2020. In conclusion, the sharp increase in seroprevalence during the second COVID-19 wave in Flanders shows that PHCPs were more at risk during the second wave compared to the first one. However, the increase was in line with the general population suggesting that PHCPs mainly got infected in their private settings.