Risk factors for breakthrough SARS-CoV-2 infection in vaccinated healthcare workers

Dietary habits, traveling and the living situation potentially influence the susceptibility to SARS-CoV-2 infection: results from healthcare workers participating in the RisCoin Study

PURPOSE

To explore occupational and non-occupational risk and protective factors for the coronavirus disease 2019 (COVID-19) in healthcare workers (HCWs).

METHODS

Serum specimens and questionnaire data were obtained between October 7 and December 16, 2021 from COVID-19-vaccinated HCWs at a quaternary care hospital in Munich, Germany, and were analyzed in the RisCoin Study.

RESULTS

Of 3,696 participants evaluated, 6.6% have had COVID-19 at least once. Multivariate logistic regression analysis identified working in patient care occupations (7.3% had COVID-19, 95% CI 6.4-8.3, Pr = 0.0002), especially as nurses, to be a potential occupation-related COVID-19 risk factor. Non-occupational factors significantly associated with high rates of the disease were contacts to COVID-19 cases in the community (12.8% had COVID-19, 95% CI 10.3-15.8, Pr < 0.0001), being obese (9.9% had COVID-19, 95% CI 7.1-13.5, Pr = 0.0014), and frequent traveling abroad (9.4% had COVID-19, 95% CI 7.1-12.3, Pr = 0.0088). On the contrary, receiving the basic COVID-19 immunization early during the pandemic (5.9% had COVID-19, 95% CI 5.1-6.8, Pr < 0.0001), regular smoking (3.6% had COVID-19, 95% CI 2.1-6.0, Pr = 0.0088), living with the elderly (3.0% had COVID-19, 95% CI 1.0-8.0, Pr = 0.0475), and frequent consumption of ready-to-eat meals (2.6% had COVID-19, 95% CI 1.1-5.4, Pr = 0.0045) were non-occupational factors potentially protecting study participants against COVID-19.

CONCLUSION

The newly discovered associations between the living situation, traveling as well as dietary habits and altered COVID-19 risk can potentially help refine containment measures and, furthermore, contribute to new mechanistic insights that may aid the protection of risk groups and vulnerable individuals.

Nirmatrelvir/Ritonavir Use and Hospitalizations or Death in a Previously Uninfected Nonhospitalized High-Risk Population With COVID-19: A Matched Cohort Study

OBJECTIVE

To determine the association of nirmatrelvir/ritonavir (NMV/r) with hospitalization or death within 30 days as compared with untreated controls previously uninfected and nonhospitalized.

METHODS

We used a matched cohort design using inverse probability of treatment weight (IPTW). Individuals prescribed NMV/r within 3 days of COVID-19 diagnosis were compared with IPTW-based untreated controls. Variables for IPTW included age, race, sex, body mass index, geographic location, vaccination status, and multiple comorbidities. Additional analyses were conducted on NMV/r-treated and propensity score-matched untreated controls.

RESULTS

Among 7615 individuals prescribed NMV/r and 62 077 controls identified between 1 January 2022 and 25 February 2023, the risk of hospitalization/death was lower among NMV/r-treated persons vs untreated controls (243 vs 3468 events; absolute risk difference [ARD], -2.36 [95% CI, -2.57 to -2.14]). The difference was significant for those >60 and ≤60 years old (ARD, -3.86 [95% CI, -4.19 to -3.54] vs -0.27 [95% CI, -0.51 to -0.03]) and for persons asymptomatic and symptomatic (ARD, -7.09 [95% CI, -7.62 to -6.55] vs -1.46 [95% CI, -1.66 to -1.25]). Significant benefit was observed among individuals unvaccinated and vaccinated, with or without a booster dose.

CONCLUSIONS

NMV/r is associated with a significant reduction in 30-day hospitalization or death among individuals previously uninfected and nonhospitalized.

Predictors of COVID-19 infection among health care workers in Harare City, Zimbabwe, 2021

Introduction

preventing COVID-19 infection among health workers maintains the health system capacity and reduces secondary transmission. Of 506 health workers tested for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in Harare City between December 2020 and February 2021 (second wave), 128 (25%) tested positive, affecting service delivery. We investigated factors associated with COVID-19 infection and described breakthrough infections among health workers.

Methods

we conducted a cross-sectional study in Harare City. Interviews were conducted with 467 health workers to determine behavioral, occupational, and non-occupational factors associated with COVID-19 infection. Fifteen key informants were interviewed to verify responses. Records and line-list were reviewed to verify cases, outcomes, and vaccination status. Observations were done to check adherence to prevention measures. Epi-info generated means, frequencies, proportions and conducted univariate, bivariate and multivariate analysis. Statistical significance was at p-value<0.05.

Results

we interviewed 467 health workers, 166 (35.5%) had a history of COVID-19 infection. Females were the majority 357 (76.4%), mostly nurses 200 (42.8%). Those not trained on infection control measures in the past six months (aOR=2.13; 95%CI 1.06-4.27; p=0.03), not observing social distance at mealtimes (aOR=6.33; 95%CI 3.36-11.89; p<0.01), having a household COVID-19 case (aOR=9.03; 95%CI 3.93-20.76; p<0.01) and not properly wearing facemasks (aOR=16.68; 95%CI 9.39-29.61; p<0.01) were significantly associated COVID-19 infection. Of 378 health workers fully vaccinated, 39 (10.3%) had breakthrough infections. Most with breakthrough infections, 33 (84.6%) had asymptomatic or mild disease. One death was recorded, a female, not vaccinated, with uncontrolled diabetes.

Conclusion

predictors of COVID-19 infection among health workers were, no training on infection and prevention and control (IPC) measures, lack of social distancing at mealtimes, improper use of facemasks, and having a COVID-19 case at household level. We conducted refresher training to strengthen infection control measures.

Higher Delta variant-specific neutralizing antibodies prevented infection in close contacts vaccinated with ancestral mRNA vaccines during the SARS-CoV-2 Delta wave

Identification of the risk factors and the high-risk groups which are most vulnerable is critical in COVID-19 disease management at a population level. Evaluating the efficacy of vaccination against infections is necessary to determine booster vaccination strategies for better protection in high-risk groups. In this study, we recruited 158 mRNA-vaccinated individuals during the Delta wave of SARS-CoV-2 infections in Singapore and examined the antibody profiles of infected individuals. We found that, despite high exposure due to communal living conditions in proximity, 4% of individuals (6/158) had PCR-confirmed infections and 96% (152/158) remained uninfected. Time-course analysis of the antibody profile at the start and the end of quarantine period showed Delta-specific boosting of anti-spike antibody response in 57% of the uninfected individuals (86/152). In the remaining 43% of the uninfected individuals (66/152) with no Delta-specific antibody boost, we found a higher Delta-specific antibody response at the start of quarantine period, which correlated with higher Delta pseudovirus neutralizing capacity. Our findings indicate that a higher basal variant-specific antibody response in the mRNA-vaccinated individuals contributes to better protection against infections by the new emerging SARS-CoV-2 variants.

Acceptance of COVID-19 vaccine booster dose among the people of Bangladesh: A cross-sectional study

Vaccine booster dose (VBD) provides a potential therapeutic alliance in preventing breakthrough infection and new variant's arrival while preserving long-lasting host immunity. This study aimed to analyze COVID-19 VBD willingness and identified the key determinants of VBD acceptance among the general people of Bangladesh. This survey-based study applied a quantitative research paradigm. A validated, anonymous, and multi-item questionnaire was adopted through a theoretical review of pertinent literature on the topic. Data were collected between August 2022─October 2022, and sampling was done randomly. A total of 704 individuals were invited via face-to-face interview approach; however, 13.8 % of them declined to give consent, which resulted in the participation of 607 potential respondents. The main outcome measure was COVID-19 VBD acceptance willingness. Binary logistic regression analysis was conducted to rationalize the study's objectives. The pooled COVID-19 booster vaccine acceptance rate was 70.0 % (95 % confidence Interval [CI]: 67─73) among Bangladeshi people. An analysis of binary logistic regression revealed that, out of 14 potential factors, "efficacy", "repeated immunity", "communication", and "trust" showed highly significant positive association (adjusted odds ratio [aOR ] = 2.151 95 % CI: 1.391─ 3.508, aOR = 2.033 95 % CI: 1.299─ 3.181, and aOR = 2.552 95 % CI: 1.557─4.183 respectively, p<0.01), and "equal safety", "risk-benefit ratio" and "community protection" had significant positive association (aOR = 1.739 95 % CI: 1.070─2.825, aOR = 1.712 95 % CI: 1.116─2.627, and aOR = 1.628 95 % CI: 1.395─0.998, p<0.05) with VBD acceptance. However, post-vaccination "side effects" showed significant negative (aOR = 0.393 95 % CI: 0.237─0.674, p<0.01) associations with VBD acceptance. The odds of accepting the COVID-19 vaccine booster was found 1.26, and it was found insignificant (p>0.05) in the Chi-squared test. Bangladeshi people expressed a moderately high level response to COVID-19 VBD acceptance. A positive attitude towards the COVID-19 VBD is an outcome of this study, regardless of the circumstances, as far as safety, efficacy, perceived health benefits, communication, trust, and community resistance are concerned. Post-vaccination side effects fear was the primary reason for booster dose skepticism as well as a barrier to administering booster shots. The confidence in COVID-19 VBD will be boosted when mass people are effectively communicated and vaccine's data become more available publicly.

Molnupiravir Use and 30-Day Hospitalizations or Death in a Previously Uninfected Nonhospitalized High-risk Population With COVID-19

BACKGROUND

Clinical benefit of molnupiravir (MPV) in coronavirus disease 2019 (COVID-19)-infected subpopulations is unclear.

METHODS

We used a matched cohort study design to determine the rate of hospitalization or death within 30 days of COVID-19 diagnosis among MPV treated and untreated controls. Participants were nonhospitalized, previously uninfected Veterans with a first confirmed severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection between 1 January and 31 August 2022, who were prescribed MPV within 3 days of COVID-19 diagnosis, and matched individuals who were not prescribed MPV.

RESULTS

Among 1459 matched pairs, the incidence of hospitalization/death was not different among MPV treated versus untreated controls (48 vs 44 cases; absolute risk difference [ARD], 0.27; 95% confidence interval [CI], -.94 to 1.49). No benefit was observed among those >60 or ≤60 years old (ARD, 0.27; 95% CI, -1.25 to 1.79 vs ARD, -0.29; 95% CI, -1.22 to 1.80), those with specific comorbidities, or by vaccination status. A significant benefit was observed in asymptomatic but not in symptomatic persons (ARD, -2.80; 95% CI, -4.74 to -.87 vs ARD, 1.12; 95% CI -.31 to 2.55). Kaplan-Meier curves did not show a difference in proportion of persons who were hospitalized or died among MPV treated compared with untreated controls (logrank P = .7).

CONCLUSIONS

MPV was not associated with a reduction in hospitalization or death within 30 days of COVID-19 diagnosis. A subgroup of patients presenting without symptoms experienced a benefit.

Contamination of SARS-CoV-2 RNA on personal protective equipment and environmental surfaces in nonpatient entry area of a Fangcang shelter hospital

OBJECTIVES

To determine the extent of contamination of personal protective equipment (PPE) and surfaces by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in the nonpatient entry area of a Fangcang shelter hospital, the medical staff accommodation area, and the staff transport bus.

METHODS

We collected 816 samples from the nonpatient entry area and floors in a Fangcang shelter hospital, medical staff accommodation area, and scheduled bus, and the five major types of PPE used from April 13 to May 18, 2022. SARS-CoV-2 ribonucleic acid (RNA) was detected by reverse transcription-polymerase chain reaction.

RESULTS

Overall, 22.2% of PPE samples were positive for SARS-CoV-2 RNA. Boot covers and gowns were the most contaminated types of PPE. The positive PPE contamination rate of staff collecting respiratory specimens was significantly higher than that of the general-treatment staff group (35.8% vs. 12.2%) and cleaner group (35.8% vs. 26.4%), p < 0.01. In total, 27 of 265 (10.2%) environmental surface samples were positive for SARS-CoV-2 RNA. The contamination-positive rates were 26.8% (22/82), 5.4% (4/74), and 0.9% (1/109) for contaminated, potentially contaminated, and clean zones, respectively. SARS-CoV-2 RNA was frequently detected on objects such as mobile phones, tables, computer keyboards and mice, and door handles.

CONCLUSIONS

SARS-CoV-2 RNA was widely distributed on high-touch surfaces and on PPE in the contaminated zone of the Fangcang shelter hospital, implying a potentially high infection risk for healthcare workers. Our findings emphasize the need to ensure adequate environmental cleaning, improve hand hygiene, and reduce the risk of infection. Additionally, prevention of self-contamination during PPE donning and doffing is complex and needs more research.

COVID-19 Booster Doses: A Multi-Center Study Reflecting Healthcare Providers' Perceptions

(1) Background: During 2019, the COVID-19 pandemic was threatening healthcare services and workers, and acquiring immunity was an option to stop or limit the burden of this pandemic. Herd immunity was a top priority worldwide as the virus was spreading rapidly. It was estimated that 67% of the total global population should be immunized against COVID-19 to achieve herd immunity. The aim of the current study is to investigate different perceptions of healthcare workers in the Kingdom of Bahrain and Egypt using an online survey in an attempt to evaluate their awareness and concerns regarding new variants and booster doses. (2) Methods: This study conducted a survey on healthcare workers in the Kingdom of Bahrain and Egypt about their perception and concerns on the COVID-19 vaccines. (3) Results: The study found that out of 389 healthcare workers 46.1% of the physicians were not willing to take the booster doses (p = 0.004). Physicians also did not support taking the COVID-19 vaccine as an annual vaccine (p = 0.04). Furthermore, to assess the association between the type of vaccine taken with the willingness of taking a booster vaccine, healthcare workers beliefs on vaccine effectiveness (p = 0.001), suspension or contact with patients (p = 0.000), and infection after COVID-19 vaccination (p = 0.016) were significant. (4) Conclusion: Knowledge about vaccine accreditation and regulation should be dispersed more widely to ensure that the population has a positive perception on vaccine safety and effectiveness.

Transmission and Risk Factors of COVID-19 among Health Care Workers

Coronavirus disease 2019 (COVID-19) poses a significant occupational risk factor to health care workers (HCWs). As in previous events, this occupational risk amplifies and compounds the adverse impact of the pandemic. We conducted a narrative review summarizing risk factors associated with severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) transmission in HCWs. We searched for original observational studies (including case-control, cross-sectional, prospective and retrospective cohorts) using PubMed, Scopus, and Google Scholar. A total of 22 articles were reviewed, including eligible English articles published between April 2020 and May 2022. Job category, work environment, personal protective equipment (PPE) noncompliance, lack of PPE awareness and training, unvaccinated status, and competing community and household exposures were identified as risk factors for SARS-CoV-2 transmission among HCWs. Effective measures to protect HCWs from SARS-CoV-2 need to account for the identified occupational risk factors. Identifying and understanding COVID-19 risk factors among HCWs must be considered a public health priority for policy makers to mitigate occupational and community transmission in current and future epidemics.

Profile of COVID-19 breakthrough cases and its comparison with unvaccinated COVID-19 cases among healthcare workers in a tertiary care centre in North Kerala

Background

Healthcare workers (HCWs) were the most vulnerable group during COVID-19 pandemic and had faced many challenges including high rate of breakthrough infections.

Aims

To study the incidence of reported breakthrough infections among HCWs in Government Medical College, Kozhikode and to compare profile of COVID-19 infection between fully vaccinated and unvaccinated COVID-19 positive HCWs.

Settings and Design

The research was conducted as a prospective study for a duration of 78 weeks from 1st of March 2020 through 31st of August 2021 in Government Medical College, Kozhikode.

Methods and Material

The study was conducted among HCWs in a COVID-19 tertiary care institute. Real-time data were collected from 401 breakthrough cases and 390 unvaccinated COVID-19 positive HCWs through telephonic interviews.

Statistical Analysis Used

Univariate analysis was done using frequency for categorical variables and mean and standard deviation for quantitative variables. Chi-square test was used to find out statistical significance.

Results

Incidence of breakthrough infection was found to be 5.62% with 43.3% being asymptomatic. Fever was the most predominant symptom (62.5%). None of the breakthrough cases developed complication requiring intensive care (ICU). There was a reduction in incidence of acute post-COVID-19 syndrome in vaccinated group (17.45%) compared to unvaccinated group (57.2%).

Conclusions

COVID-19 vaccination plays a key role in preventing severity, complication, and ICU admissions in COVID-19 infection. Incidence of post-COVID-19 syndrome is also less among fully vaccinated compared to unvaccinated individuals.

COVID-19 booster vaccination uptake and infection breakthrough amongst health care workers in Wales: A national prospective cohort study

BACKGROUND

From September 2021, Health Care Workers (HCWs) in Wales began receiving a COVID-19 booster vaccination. This is the first dose beyond the primary vaccination schedule. Given the emergence of new variants, vaccine waning vaccine, and increasing vaccination hesitancy, there is a need to understand booster vaccine uptake and subsequent breakthrough in this high-risk population.

METHODS

We conducted a prospective, national-scale, observational cohort study of HCWs in Wales using anonymised, linked data from the SAIL Databank. We analysed uptake of COVID-19 booster vaccinations from September 2021 to February 2022, with comparisons against uptake of the initial primary vaccination schedule. We also analysed booster breakthrough, in the form of PCR-confirmed SARS-Cov-2 infection, comparing to the second primary dose. Cox proportional hazard models were used to estimate associations for vaccination uptake and breakthrough regarding staff roles, socio-demographics, household composition, and other factors.

RESULTS

We derived a cohort of 73,030 HCWs living in Wales (78% female, 60% 18-49 years old). Uptake was quickest amongst HCWs aged 60 + years old (aHR 2.54, 95%CI 2.45-2.63), compared with those aged 18-29. Asian HCWs had quicker uptake (aHR 1.18, 95%CI 1.14-1.22), whilst Black HCWs had slower uptake (aHR 0.67, 95%CI 0.61-0.74), compared to white HCWs. HCWs residing in the least deprived areas were slightly quicker to have received a booster dose (aHR 1.12, 95%CI 1.09-1.16), compared with those in the most deprived areas. Strongest associations with breakthrough infections were found for those living with children (aHR 1.52, 95%CI 1.41-1.63), compared to two-adult only households. HCWs aged 60 + years old were less likely to get breakthrough infections, compared to those aged 18-29 (aHR 0.42, 95%CI 0.38-0.47).

CONCLUSION

Vaccination uptake was consistently lower among black HCWs, as well as those from deprived areas. Whilst breakthrough infections were highest in households with children.

Transition of Antibody Titers after SARS-CoV-2 mRNA Vaccination in Japanese Healthcare Workers

Since February 2021, healthcare workers in Japan have been preferentially vaccinated with a messenger RNA vaccine (BNT162b2; Pfizer/BioNTech) against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). While many studies have confirmed that this vaccine is highly effective in reducing hospitalization and deaths from coronavirus disease 2019 (COVID-19), antibody titers tend to decline at 3 months after vaccination, leading to a risk of breakthrough infections. Thus, information is needed to support the decision regarding the 3rd vaccination. In this study, we investigated the transition of anti-SARS-CoV-2 spike protein receptor-binding domain (RBD) IgG and neutralizing antibody titers in 37 vaccinated Japanese healthcare workers. Samples were collected 6 times starting before vaccination until 6 months after the second vaccination. The levels of anti-SARS-CoV-2 RBD IgG peaked 1 week after the 2nd vaccination, then declined over time and decreased to < 10% at 6 months after the 2nd vaccination. Additionally, approximately one-third of the healthcare workers were seronegative for the Omicron variant 6 months after the 2nd vaccination. Workers with low anti-SARS-CoV-2 RBD IgG levels also had low neutralizing antibody titers. These data support booster dose administration for healthcare workers, especially those with low anti-SARS-CoV-2 RBD IgG levels.

SARS-CoV-2 breakthrough infections during the second wave of COVID-19 at Pune, India

Breakthrough infections following SARS-CoV-2 vaccination remain the global concern. The current study was conducted during the second wave of COVID-19 (1st March-7th July 2021) in Pune, India, at two tertiary care hospitals. Of the 6,159 patients diagnosed as COVID-19, 372/2,210 (16.8%) were breakthrough infections. Of these, 81.1 and 18.8% received one or two doses of Covishield or Covaxin, respectively. Of note, 30.7% patients were with comorbidities, hypertension being the commonest (12.44%). The majority of infections were mild (81.2%). Forty-three patients with breakthrough infections were hospitalized with severe (n = 27, 62.8%) or moderate (n = 16, 37.2%) disease. The receptor binding domain (RBD) sequences from vaccinated (n = 126) and non-vaccinated (n = 168) samples were used for variant analysis. The delta variant was predominant followed by kappa in both vaccinated and non-vaccinated groups. Viral load (qRT-PCR) was not different among these categories. Full-genome comparisons of sequences in relation to vaccination status did not identify any mutation characteristic of the vaccinated group. Irrespective of the number of doses, neutralizing antibody titers (PRNT50) during the first week of clinical disease were higher in the vaccinated patients than the unvaccinated category. In conclusion, though not completely, SARS-CoV-2 vaccines used for country-wide immunization did reduce disease severity among the individuals without any comorbidity by inducing rapid immune response against distinctly different delta and kappa variants. The utility against emerging variants with further mutations need to be carefully examined.

Community risks for SARS-CoV-2 infection among fully vaccinated US adults by rurality: A retrospective cohort study from the National COVID Cohort Collaborative

BACKGROUND

While COVID-19 vaccines reduce adverse outcomes, post-vaccination SARS-CoV-2 infection remains problematic. We sought to identify community factors impacting risk for breakthrough infections (BTI) among fully vaccinated persons by rurality.

METHODS

We conducted a retrospective cohort study of US adults sampled between January 1 and December 20, 2021, from the National COVID Cohort Collaborative (N3C). Using Kaplan-Meier and Cox-Proportional Hazards models adjusted for demographic differences and comorbid conditions, we assessed impact of rurality, county vaccine hesitancy, and county vaccination rates on risk of BTI over 180 days following two mRNA COVID-19 vaccinations between January 1 and September 21, 2021. Additionally, Cox Proportional Hazards models assessed the risk of infection among adults without documented vaccinations. We secondarily assessed the odds of hospitalization and adverse COVID-19 events based on vaccination status using multivariable logistic regression during the study period.

RESULTS

Our study population included 566,128 vaccinated and 1,724,546 adults without documented vaccination. Among vaccinated persons, rurality was associated with an increased risk of BTI (adjusted hazard ratio [aHR] 1.53, 95% confidence interval [CI] 1.42-1.64, for urban-adjacent rural and 1.65, 1.42-1.91, for nonurban-adjacent rural) compared to urban dwellers. Compared to low vaccine-hesitant counties, higher risks of BTI were associated with medium (1.07, 1.02-1.12) and high (1.33, 1.23-1.43) vaccine-hesitant counties. Compared to counties with high vaccination rates, a higher risk of BTI was associated with dwelling in counties with low vaccination rates (1.34, 1.27-1.43) but not medium vaccination rates (1.00, 0.95-1.07). Community factors were also associated with higher odds of SARS-CoV-2 infection among persons without a documented vaccination. Vaccinated persons with SARS-CoV-2 infection during the study period had significantly lower odds of hospitalization and adverse events across all geographic areas and community exposures.

CONCLUSIONS

Our findings suggest that community factors are associated with an increased risk of BTI, particularly in rural areas and counties with high vaccine hesitancy. Communities, such as those in rural and disproportionately vaccine hesitant areas, and certain groups at high risk for adverse breakthrough events, including immunosuppressed/compromised persons, should continue to receive public health focus, targeted interventions, and consistent guidance to help manage community spread as vaccination protection wanes.

Why Molnupiravir Fails in Hospitalized Patients

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causative agent of coronavirus disease 2019 (COVID-19), has radically altered daily life. Effective antiviral therapies to combat COVID-19, especially severe disease, remain scarce. Molnupiravir is an antiviral that has shown clinical efficacy against mild-to-moderate COVID-19 but failed to provide benefit to hospitalized patients with severe disease. Here, we explained the mechanism behind the failure of molnupiravir in hospitalized patients and identified alternative dosing strategies that would improve therapeutic outcomes in all patients with COVID-19. We showed that delaying therapy initiation markedly decreased the antiviral effect of molnupiravir, and these results were directly related to intracellular drug triphosphate pools and intracellular viral burden at the start of therapy. The adverse influence of therapeutic delay could be overcome by increasing drug exposure, which increased intracellular molnupiravir triphosphate concentrations that inhibited viral replication. These findings illustrated that molnupiravir must be administered as early as possible following COVID-19 symptom onset to maximize therapeutic efficacy. Higher doses may be effective in patients hospitalized with severe disease, but the safety of high-dose molnupiravir regimens is unknown. Our findings could be extended to design effective regimens with nucleoside analogs for other RNA viruses, especially those with pandemic potential. IMPORTANCE In this study, we showed that early intervention with molnupiravir resulted in a greater antiviral effect, and we explained the mechanism behind this phenomenon. Our results predicted and explained the failure of molnupiravir in hospitalized patients and highlighted the utility of preclinical pharmacodynamic studies to design optimal antiviral regimens for the treatment of viral diseases. This contrasts with the procedure that was implemented early in the pandemic in which clinical studies were conducted in the absence of preclinical experimentation. These findings are significant and demonstrated the importance of experimental approaches in antiviral development for treatments against COVID-19 as well as other viral diseases.

Breakthrough Infections: Clinical Profile and Outcomes of COVID-19 Vaccinated and Unvaccinated People From a Tertiary Care Hospital

Introduction Despite the availability of a vaccine and extensive vaccination, breakthrough infections are commonly noted, which is jeopardizing the vaccine-based protection against COVID-19. The present study aims to evaluate COVID-19 breakthrough infections and to compare the clinical profile and outcomes of the vaccinated and unvaccinated populations.  Methods A retrospective observational study was conducted for two months (March-April 2021), and all cases reported during the study period were included in the study. Socio-demographic details, COVID-19 profiles, clinical outcomes, vaccination statuses, and types of vaccine were collected from the patients. Further, COVID-19-positive samples were screened for lineages using next-generation sequencing (NGS). Results Of the total 103 patients included in the study, 79 (76.7%) were symptomatic and 24 (23.3%) were asymptomatic. Only 32% were vaccinated and 68% were unvaccinated. 29.2% were hospitalized due to COVID-19 and all of them were unvaccinated. The mortality among hospitalized patients was extremely high (60%). The time to positivity after complete vaccination was noted to be 37.09±23.74 days. The unvaccinated study participants showed lower Cycle threshold (Ct) values (E Gene/N Gene: 17.38±4.53) as compared to the vaccinated people (E Gene/N Gene: 22±4.25). The Delta (B. 1.1. 629) (76.7%) was the predominant variant among the study population followed by AY.4 (20.4%) and Kappa (2.9%) variants. Conclusion Although the vaccination does not restrict/avoid infection, it appears to protect the vaccinated people from severe forms of COVID-19. Also, the higher Ct values among vaccinated people indicate that the viral load among such people may be lower and, therefore, minimizes viral transmission.

Risk factors for SARS-CoV-2 infection after primary vaccination with ChAdOx1 nCoV-19 or BNT162b2 and after booster vaccination with BNT162b2 or mRNA-1273: A population-based cohort study (COVIDENCE UK)

Background

Little is known about how demographic, behavioural, and vaccine-related factors affect risk of post-vaccination SARS-CoV-2 infection. We aimed to identify risk factors for SARS-CoV-2 infection after primary and booster vaccinations.

Methods

This prospective, population-based, UK study in adults (≥16 years) vaccinated against SARS-CoV-2 assessed risk of breakthrough SARS-CoV-2 infection up to February, 2022, for participants who completed a primary vaccination course (ChAdOx1 nCoV-19 or BNT162b2) and those who received a booster dose (BNT162b2 or mRNA-1273). Cox regression models explored associations between sociodemographic, behavioural, clinical, pharmacological, and nutritional factors and test-positive breakthrough infection, adjusted for local weekly SARS-CoV-2 incidence.

Findings

1051 (7·1%) of 14 713 post-primary participants and 1009 (9·5%) of 10 665 post-booster participants reported breakthrough infection, over a median follow-up of 203 days (IQR 195–216) and 85 days (66–103), respectively. Primary vaccination with ChAdOx1 (vs BNT162b2) was associated with higher risk of infection in both post-primary analysis (adjusted hazard ratio 1·63, 95% CI 1·41–1·88) and after an mRNA-1273 booster (1·26 [1·00–1·57] vs BNT162b2 primary and booster). Lower risk of infection was associated with older age (post-primary: 0·97 [0·96–0·97] per year; post-booster: 0·97 [0·97–0·98]), whereas higher risk of infection was associated with lower educational attainment (post-primary: 1·78 [1·44–2·20] for primary/secondary vs postgraduate; post-booster: 1·46 [1·16–1·83]) and at least three weekly visits to indoor public places (post-primary: 1·36 [1·13–1·63] vs none; post-booster: 1·29 [1·07–1·56]).

Interpretation

Vaccine type, socioeconomic status, age, and behaviours affect risk of breakthrough infection after primary and booster vaccinations.

Funding

Barts Charity, UK Research and Innovation Industrial Strategy Challenge Fund.

Acceptance of COVID-19 Vaccine Booster Doses Using the Health Belief Model: A Cross-Sectional Study in Low-Middle- and High-Income Countries of the East Mediterranean Region

Coronavirus disease (COVID-19) booster doses decrease infection transmission and disease severity. This study aimed to assess the acceptance of COVID-19 vaccine booster doses in low, middle, and high-income countries of the East Mediterranean Region (EMR) and its determinants using the health belief model (HBM). In addition, we aimed to identify the causes of booster dose rejection and the main source of information about vaccination. Using the snowball and convince sampling technique, a bilingual, self-administered, anonymous questionnaire was used to collect the data from 14 EMR countries through different social media platforms. Logistic regression analysis was used to estimate the key determinants that predict vaccination acceptance among respondents. Overall, 2327 participants responded to the questionnaire. In total, 1468 received compulsory doses of vaccination. Of them, 739 (50.3%) received booster doses and 387 (26.4%) were willing to get the COVID-19 vaccine booster doses. Vaccine booster dose acceptance rates in low, middle, and high-income countries were 73.4%, 67.9%, and 83.0%, respectively (p < 0.001). Participants who reported reliance on information about the COVID-19 vaccination from the Ministry of Health websites were more willing to accept booster doses (79.3% vs. 66.6%, p < 0.001). The leading causes behind booster dose rejection were the beliefs that booster doses have no benefit (48.35%) and have severe side effects (25.6%). Determinants of booster dose acceptance were age (odds ratio (OR) = 1.02, 95% confidence interval (CI): 1.01-1.03, p = 0.002), information provided by the Ministry of Health (OR = 3.40, 95% CI: 1.79-6.49, p = 0.015), perceived susceptibility to COVID-19 infection (OR = 1.88, 95% CI: 1.21-2.93, p = 0.005), perceived severity of COVID-19 (OR = 2.08, 95% CI: 137-3.16, p = 0.001), and perceived risk of side effects (OR = 0.25, 95% CI: 0.19-0.34, p < 0.001). Booster dose acceptance in EMR is relatively high. Interventions based on HBM may provide useful directions for policymakers to enhance the population's acceptance of booster vaccination.

Prognosis of COVID-19 in the middle eastern population, knowns and unknowns

Since its emergence in China in 2019, the SARS-CoV-2 virus has affected all countries worldwide. The virus is easily transmitted from one person to another via infected aerosols or contaminated surfaces. Unlike its counterparts, the prognosis of COVID-19 ranges from asymptomatic to critical disease or death. Several factors play a role in determining the severity of the disease in infected patients. Among others, is the pre-existence of an underlying medical condition such as diabetes, cancer, and others. Furthermore, although children are less prone to the severe form of the COVID-19 disease, they require attention due to the report of many atypical presentations of the infection, post-asymptomatic exposure. In the Middle East, little is known about the prognosis of the SARS-CoV-2 infection in high-risk categories, notably patients with diabetes, cancer, and pregnant women. The aim of this review is to summarize the current knowledge about this group of population in the middle eastern region as well as to highlight the gap in the literature. We have found that the majority of the papers were from the Gulf countries. Although, few studies were conducted; high-risk patients appear to have an increased risk of morbidity and mortality from COVID-19 compared to their counterparts. Higher levels of inflammatory markers, C-reactive protein, erythrocyte sedimentation rate, D-dimer, and ferritin levels were also observed. Children are often asymptomatic or present with atypical presentations. More studies should be conducted to determine the clinical biomarkers of COVID-19 in high-risk categories to help in patient risk stratification and management in the middle eastern population.

SARS-CoV-2 Infectivity and Antibody Titer Reduction for 6 Months After Second Dose of BNT162b2 mRNA Vaccine in Health Care Workers: A Prospective Cohort Study

Several studies reported that severe acute respiratory syndrome coronavirus-2 antibody levels change over 6 months in participants receiving the vaccination. From the enrolled 272 health care workers (HCWs), blood samples were obtained at 2, 16, and 24 weeks after the second vaccination dose. In the 267 noninfected HCWs, the neutralizing antibodies decreased by 23.9%, and the anti-spike/receptor binding domain antibody decreased by 53.8% at 24 weeks. We observed no significant difference in antibody reduction between the sexes; however, in younger individuals, there was higher antibody formation and lower reduction rates of the neutralizing antibody. In 3 HCWs with breakthrough infections, the antibody levels were relatively low just before the coronavirus disease 2019 infection. In conclusion, as antibody titers decrease over time after the second vaccination dose and HCWs with low antibody titers tend to have a high probability of breakthrough infection, an additional dose should be considered after several months. Blood samples were obtained from health care workers at 2, 16, and 24 weeks after a second vaccination dose. Antibody titers decreased over time and the participants with low antibody titers tended to have a high probability of breakthrough infection.

Factors Associated With COVID-19 Breakthrough Infections in Large Midwestern Healthcare System: Implications for Vulnerable Healthcare Personnel

OBJECTIVE

The aim of the study is to identify factors associated with breakthrough infection among a cohort of Midwestern healthcare personnel (HCP).

METHODS

SARS-CoV-2-positive test results between March 1, 2020, and July 31, 2021, were collected from electronic medical records of HCP to identify breakthrough infections.

RESULTS

Healthcare personnel who were younger than 35 years, received the Pfizer vaccine, and worked in COVID clinical units had greater adjusted odds of breakthrough infection. COVID infection before full vaccination was associated with reduced odds of breakthrough infection.

CONCLUSIONS

Our study concluded that the most vulnerable HCP are younger, working in COVID-19 clinical units, and received Pfizer-BioNTech primary series vaccines. Healthcare personnel who had COVID before vaccination were at reduced risk of breakthrough infection, indicating that supplemental immunity could better protect at-risk HCP groups.

Seroprevalence of SARS-CoV-2 Infection Among Working Women and Impact of Workplace Restrictions

Objective

To determine the prevalence of SARS-CoV-2 virus infection among female workers who were restricted to working from home compared with those who continued to attend in-person work.

Methods

As part of national surveillance program, serum samples for SARS-CoV-2 antibody testing and nasopharyngeal swabs for SARS-CoV-2 PCR were obtained on 1636 female school staff and salon/spa workers who were restricted to work remotely (restricted group) and 1190 female health-care workers who continued in-person work (unrestricted group).

Results

Seropositivity rate was 5.1% among the restricted and 22.7% among the unrestricted group (P < 0.0001). Presence of symptoms at baseline (adjusted odds ratio [aOR], 2.88; 95% CI 2.09–3.97), contact with a confirmed case (aOR 2.34; 95% CI 1.37–3.98), and unrestricted work type (aOR 4.71; 95% CI 3.24–6.86) were associated with a higher risk of infection, while increasing age was associated with a lower risk of infection.

Conclusion

Prevalence of SARS-CoV-2 infection as determined by seropositivity was higher among women who were not subject to workplace restrictions.

Nomogram Model for Prediction of SARS-CoV-2 Breakthrough Infection in Fujian: A Case–Control Real-World Study

SARS-CoV-2 breakthrough infections have been reported because of the reduced efficacy of vaccines against the emerging variants globally. However, an accurate model to predict SARS-CoV-2 breakthrough infection is still lacking. In this retrospective study, 6,189 vaccinated individuals, consisting of SARS-CoV-2 test-positive cases (n = 219) and test-negative controls (n = 5970) during the outbreak of the Delta variant in September 2021 in Xiamen and Putian cities, Fujian province of China, were included. The vaccinated individuals were randomly split into a training (70%) cohort and a validation (30%) cohort. In the training cohort, a visualized nomogram was built based on the stepwise multivariate logistic regression. The area under the curve (AUC) of the nomogram in the training and validation cohorts was 0.819 (95% CI, 0.780–0.858) and 0.838 (95% CI, 0.778–0.897). The calibration curves for the probability of SARS-CoV-2 breakthrough infection showed optimal agreement between prediction by nomogram and actual observation. Decision curves indicated that nomogram conferred high clinical net benefit. In conclusion, a nomogram model for predicting SARS-CoV-2 breakthrough infection based on the real-world setting was successfully constructed, which will be helpful in the management of SARS-CoV-2 breakthrough infection.

The Provision of Dental Care to Post COVID-19 Survivors. A Concise Review

Aims

It has been reported that there are a certain percentage of COVID-19 patients who recover but suffer from devastating permanent organ damage or failure. Others suffer from long Covid syndrome, with prolonged symptoms that persist more than 12 weeks. However, there is scarcity of literature regarding the provision of dental treatment for these two groups of patients. This manuscript reviews the impact of multi-system involvement on the provision of dental care to these patients.

Materials and methods

A search of literature was done in PubMed-Medline and Scopus databases to review the available literature on COVID-19 impacts on pulmonary, cardiovascular, haematologic, renal, gastrointestinal, endocrine, and neurologic systems and respective management in dental clinical settings.

Results

The literature search from PubMed-Medline and Scopus databases resulted in 74 salient articles that contributed to the concise review on COVID-19 effects on pulmonary, cardiovascular, haematologic, renal, gastrointestinal, endocrine, and neurologic systems and/or its respective dental management recommendations.

Conclusions

This concise review covers the management of post COVID-19 patients with pulmonary, cardiovascular, haematologic, renal, gastrointestinal, endocrine, or neurologic system complications.

Acceptance of COVID-19 Booster Vaccination Based on the Protection Motivation Theory (PMT): A Cross-Sectional Study in China

The promotion of the booster shots against severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) infection is an open issue to be discussed. Little is known about the public intention and the influencing factors regarding the booster vaccine. A cross‐sectional survey in Chinese adults was conducted using an online questionnaire, which designed on the basis of protection motivation theory (PMT) scale and vaccine hesitancy scale (VHS). Hierarchical multiple regression was used to compare the fitness of the PMT scale and VHS for predicting booster vaccination intention. Multivariable logistic regression was used to analyze the factors associated with the acceptance. Six thousand three hundred twenty‐one (76.8%) of participants were willing to take the booster shot. However, the rest of the participants (23.2%) were still hesitant to take the booster vaccine. The PMT scale was more powerful than the VHS in explaining the vaccination intention. Participants with high perceived severity (adjusted odds ratio [aOR] = 0.69) and response cost (aOR = 0.47) were less willing to take the booster shots, but participants with high perceived susceptibility (aOR = 1.19), response efficacy (aOR = 2.13), and self‐efficacy (aOR = 3.33) were more willing to take the booster shots. In summary, interventions based on PMT can provide guidance to ensure the acceptance of the booster vaccine.

COVID-19 Infection in Vaccinated Healthcare Professionals

Background: There are different types of Coronavirus disease (COVID-19) vaccines available presently, and their emergency use has been approved by WHO worldwide on a mass scale. COVID-19 vaccine breakthrough infections have been reported worldwide. In Pakistan, there are limited data on COVID-19 vaccine breakthrough infections and their clinical course, especially in healthcare professionals (HCPs). Our study aims to investigate COVID-19 infections among vaccinated HCPs.

Methods: A prospective study was conducted on 425 healthcare professionals. Data collected from healthcare professionals included names, age, gender, number of vaccination doses, COVID-19 infection pre and post-vaccination, the severity of COVID-19 infection (if positive), and co-morbid conditions. Ethical board approval was taken. Statistical Package for Social Sciences (SPSS) version 23 (IBM Corp., Armonk, NY) was used to analyze the data.

Results: After complete vaccination, 17.27% acquired COVID-19 infection; 2.47% had COVID-19 infection both pre and post-vaccination. The mean age was 32.46 years (n=71) with a standard deviation of ±9.376. The male to female ratio was 1.53. COVID-19 PCR was positive in 95.77%. During the course of the disease, 4.2% were asymptomatic, 92.95% had mild symptoms, 1.4% were hospitalized, and 1.4% had to be managed in the intensive care unit. None of the HCPs who had received booster doses acquired a COVID-19 infection.

Conclusion: It was found that prior COVID-19 infection and vaccination do not confer immunity from infection. However, proper vaccination limits the severity, morbidity, and mortality of COVID-19 infection.

Post-Vaccination SARS-CoV-2 Infections among Health Workers at the University Hospital of Verona, Italy: A Retrospective Cohort Survey

Background: The SARS-CoV-2 vaccination campaign began on 27 December 2020 in Europe, primarily involving health workers. This study aimed to assess the SARS-CoV-2 vaccination effectiveness, as assessed by reductions in incidence, symptom severity, and further infection spreading. Methods: A retrospective cohort study was conducted on 9811 health workers operating at the Verona University Hospital, Italy, from 27 December 2020 to 3 May 2021. All health workers were offered vaccination with Comirnaty (BNT162b2, BioNTech/Pfizer, Mainz, Germany/New York, United States), and a health surveillance program was implemented with periodical swab testing. Vaccination status and clinical data were collected using an ad hoc semi-structured questionnaire and health surveillance charts. Results: As of 3rd of May, 82.5% of health workers had been vaccinated against SAR-CoV-2, and 177 (1.8%) had tested positive for SARS-CoV-2. Vaccination more than halved the cumulative incidence of SARS-CoV-2 infection and reduced by two-thirds the cumulative incidence of symptomatic subjects. In detail, most unvaccinated HWs were symptomatic; 50% reported fever, 45% reported ageusia/anosmia, and nearly 20% reported dyspnea. These percentages were much lower in HWs who had been vaccinated for at least 14 days (18% for fever and anosmia, 6% for dyspnea and ageusia). Moreover, cases of vaccine breakthrough were sixfold less likely to further spread the infection than unvaccinated HWs. Conclusions: SARS-CoV-2 vaccination reduced the infection frequency among HWs, further spreading of the infection, and the presence, severity, and duration of COVID-19-related symptoms.

Unpacking the Implications of SARS-CoV-2 Breakthrough Infections on COVID-19 Vaccination Programs

Despite an array of preventive global public health interventions, SARS-CoV-2 has continued to spread significantly, infecting millions of people across the globe weekly. Newer variants of interest and concern have continued to emerge, placing the need for policymakers to rethink prevention strategies to end the pandemic. The approval of SARS-CoV-2 vaccines for public health use in December 2020 was seen as a significant development towards pandemic control and possibly ending the pandemic. However, breakthrough infections have continued to be observed among the ‘fully vaccinated’, and the duration and sustainability of vaccine-induced immunity has remained a topical public health discourse. In the absence of accurate public health communication, the breakthrough infections and waning immunity concepts have potential to further compound vaccine hesitancy. With this viewpoint, we discuss breakthrough SARS-CoV-2 infections, waning immunity, the need for COVID-19 booster shots, vaccine inequities, and the need to address vaccine hesitancy adequately to propel global vaccination programs forward.

Risk of Vaccine Breakthrough SARS-CoV-2 Infection and Associated Factors in Healthcare Workers of Trieste Teaching Hospitals (North-Eastern Italy)

Background: Healthcare workers (HCWs) are particularly exposed to biological risk, including SARS-CoV-2 infection. In order to contrast the current pandemic and alleviate the burden of the disease on the healthcare system, a mass vaccination campaign against COVID-19 has been launched worldwide. Aim To evaluate the impact of COVID-19 vaccination in HCWs exposed to SARS-CoV-2, to describe the clinical presentation of COVID-19 in infected HCWs, and to investigate clinical and occupational risk factors for breakthrough infection. Design: Retrospective cohort study. Methods: The cohort of HCWs of Trieste Hospitals were followed up from 1 March 2020, to 30 November 2021 (21 months). All HCWs were periodically screened for SARS-CoV-2 infection by real-time PCR (RT-PCR) analysis. Clinical data were obtained through routine medical surveillance records. Risk factors for SARS-CoV-2 infection were investigated by univariable as well as multivariable logistic regression analysis. Results: Among 4394 HCWs routinely screened for SARS-CoV-2 by PCR on nasopharyngeal swab, a total of 800 incident cases were identified during the entire study period (1 March 2020 to 30 November 2021). Five hundred and sixty-four cases occurred before, and 236 after the start of the vaccination campaign against COVID-19, of whom 155 received a complete vaccination scheme before SARS-CoV-2 infection. Breakthrough infection was featured by mild or no symptoms and was significantly associated with the male sex, BMI > 25, and diabetes mellitus. Some categories of HCWs (physicians and nurse aids/auxiliary personnel) were at a higher risk of breakthrough infection. Conclusions: Fully vaccinated HCWs were less likely to acquire symptomatic as well as asymptomatic SARS-CoV-2 infection. Risk factors for SARS-CoV-2 infection after a full COVID-19 vaccination scheme included the male gender, diabetes mellitus, and overweight. HCWs with higher exposure to COVID-19 patients were at higher risk of breakthrough infection.