Partial Vaccination Research Articles

Impact of dengue vaccination choice on Zika risk: free riders and the tragedy of the commons

Dengue vaccination, long in development, has become controversial as it may cause antibody-dependent enhancement (ADE) in dengue-seronegatives. Under partial vaccine failure, ADE increases case severity and may also affect Zika infections since the two viruses are closely related.From an individual perspective, the vaccination of others appears beneficial, but becoming vaccinated oneself may increase the risk of ADE and thus serious illness, for both diseases. From a population-level perspective, vaccination is expected to reduce the spread of dengue but increase Zika incidence. Nevertheless, prior mathematical modeling research has shown that in some cases, a small number of dengue vaccinations may reduce the final size of a Zika outbreak despite increasing its ability to spread. This study reconciles these results and then evaluates individual risks to both the vaccinated and the unvaccinated in order to connect to broader themes in complex vaccination decisions, such as free riders and the tragedy of the commons. A substantial new finding is that a dual outbreak may change which vaccination decision minimizes risk, compared to single-outbreak scenarios.

Coverage evaluation survey of COVID-19 vaccination among adolescents aged 12 to 17 years in the rural field practice area of medical college near Bangalore

Background: COVID-19 vaccination in India was started from 16 January 2021. The vaccination for adolescents was started one year later. The only source of COVID-19 vaccination coverage is government data. There is a lack of external studies on COVID-19 vaccine coverage in this age group. In this regard, the present study was taken up with the objectives to assess the vaccination coverage of COVID-19 among adolescents aged 12-17 years and the factors associated with COVID-19 vaccine hesitancy. Methods: A coverage evaluation survey was done for assessing COVID-19 vaccination coverage among adolescents aged 12 to 17 years from September to December 2022 in the rural field practice area of a medical college near Bangalore. Results: Out of the 420 study subjects, 294 (70%) were fully vaccinated, 70 (16.6%) were partially vaccinated and 56 (13.4%) were unvaccinated. It was observed that the coverage of COVID-19 vaccine in the age group of 15 to 17 years was higher compared to 12 to 14 years. Conclusions: The COVID 19 vaccine coverage with two doses among adolescents aged 12-14 was 61.9% and 78.1% among 210 adolescents aged 15 to 17 years in the rural locality. The most common reason for partial vaccination was that the school did not provide the second dose and the most common reason for not being vaccinated is that the subject was not eligible for vaccination during the school vaccination campaign.

Estimated Effectiveness of JYNNEOS Vaccine in Preventing Mpox: A Multijurisdictional Case-Control Study — United States, August 19, 2022–March 31, 2023

As of March 31, 2023, more than 30,000 monkeypox (mpox) cases had been reported in the United States in an outbreak that has disproportionately affected gay, bisexual, and other men who have sex with men (MSM) and transgender persons (1). JYNNEOS vaccine (Modified Vaccinia Ankara vaccine, Bavarian Nordic) was approved by the Food and Drug Administration (FDA) in 2019 for the prevention of smallpox and mpox via subcutaneous injection as a 2-dose series (0.5 mL per dose, administered 4 weeks apart) (2). To expand vaccine access, an Emergency Use Authorization was issued by FDA on August 9, 2022, for dose-sparing intradermal injection of JYNNEOS as a 2-dose series (0.1 mL per dose, administered 4 weeks apart) (3). Vaccination was available to persons with known or presumed exposure to a person with mpox (postexposure prophylaxis [PEP]), as well as persons at increased risk for mpox or who might benefit from vaccination (preexposure mpox prophylaxis [PrEP]) (4). Because information on JYNNEOS vaccine effectiveness (VE) is limited, a matched case-control study was conducted in 12 U.S. jurisdictions,† including nine Emerging Infections Program sites and three Epidemiology and Laboratory Capacity sites,§ to evaluate VE against mpox among MSM and transgender adults aged 18-49 years. During August 19, 2022-March 31, 2023, a total of 309 case-patients were matched to 608 control patients. Adjusted VE was 75.2% (95% CI = 61.2% to 84.2%) for partial vaccination (1 dose) and 85.9% (95% CI = 73.8% to 92.4%) for full vaccination (2 doses). Adjusted VE for full vaccination by subcutaneous, intradermal, and heterologous routes of administration was 88.9% (95% CI = 56.0% to 97.2%), 80.3% (95% CI = 22.9% to 95.0%), and 86.9% (95% CI = 69.1% to 94.5%), respectively. Adjusted VE for full vaccination among immunocompromised participants was 70.2% (95% CI = -37.9% to 93.6%) and among immunocompetent participants was 87.8% (95% CI = 57.5% to 96.5%). JYNNEOS is effective at reducing the risk for mpox. Because duration of protection of 1 versus 2 doses remains unknown, persons at increased risk for mpox exposure should receive the 2-dose series as recommended by the Advisory Committee on Immunization Practices (ACIP),¶ regardless of administration route or immunocompromise status.

Vaccine Effectiveness of JYNNEOS against Mpox Disease in the United States

BackgroundIn the United States, more than 30,000 cases of mpox (formerly known as monkeypox) had occurred as of March 1, 2023, in an outbreak disproportionately affecting transgender persons and gay, bisexual, and other men who have sex with men. In 2019, the JYNNEOS vaccine was approved for subcutaneous administration (0.5 ml per dose) to prevent mpox infection. On August 9, 2022, an emergency use authorization was issued for intradermal administration (0.1 ml per dose); however, real-world effectiveness data are limited for either route.MethodsWe conducted a case–control study based on data from Cosmos, a nationwide Epic electronic health record (EHR) database, to assess the effectiveness of JYNNEOS vaccination in preventing medically attended mpox disease among adults. Case patients had an mpox diagnosis code or positive orthopoxvirus or mpox virus laboratory result, and control patients had an incident diagnosis of human immunodeficiency virus (HIV) infection or a new or refill order for preexposure prophylaxis against HIV infection between August 15, 2022, and November 19, 2022. Odds ratios and 95% confidence intervals were estimated from conditional logistic-regression models, adjusted for confounders; vaccine effectiveness was calculated as (1−odds ratio for vaccination in case patients vs. controls)×100.ResultsAmong 2193 case patients and 8319 control patients, 25 case patients and 335 control patients received two doses (full vaccination), among whom the estimated adjusted vaccine effectiveness was 66.0% (95% confidence interval [CI], 47.4 to 78.1), and 146 case patients and 1000 control patients received one dose (partial vaccination), among whom the estimated adjusted vaccine effectiveness was 35.8% (95% CI, 22.1 to 47.1).ConclusionsIn this study using nationwide EHR data, patients with mpox were less likely to have received one or two doses of JYNNEOS vaccine than control patients. The findings suggest that JYNNEOS vaccine was effective in preventing mpox disease, and a two-dose series appeared to provide better protection. (Funded by the Centers for Disease Control and Prevention and Epic Research.)

The effectiveness of COVID–19 vaccination against all–cause mortality in patients with type 2 diabetes mellitus: The observation during the initial period of the cancellation of the “Dynamic Zero Policy” in mainland China

AimsThis study aims to assess the effectiveness of COVID–19 vaccination against all–cause death in patients with type 2 diabetes mellitus (T2DM). MethodsSubjects were patients with T2DM who were administered by general practitioner (GP). Use electronic exchange platform to obtain the information on COVID–19 vaccination, all–cause deaths and risk factors. Logistic regression models were used to calculate the odd ratio (OR) and 95% CI for the association between COVID–19 vaccination and mortality. The vaccine effectiveness (VE) was calculated as (1- adjusted OR) × 100%. ResultsA total of 26,916 subjects had 53.81%, 17.65%, and 23.43% coverage for the booster, full, and partial COVID-19 vaccination, reported 328 deaths and a mortality of 1.2%. The adjusted OR (95%CI) was 0.85(0.60–1.21) for those received partial vaccination, 0.31(0.22–0.43) for those received full vaccination, and 0.12(0.08–0.18) for those received booster vaccination, compared to the unvaccinated individuals. The VE (95%CI) was 88.00%(82.30–91.80) of booster vaccination, 69.30%(56.60–78.30) of full vaccination, and 17.60%(-17.10–42.00) of partial vaccination. ConclusionCOVID–19 vaccination could effectively prevent the all–cause death in patients with T2DM during the omicron variant outbreak period, after the cancellation of the “Dynamic Zero Policy” in mainland China.

The added effect of non-pharmaceutical interventions and lifestyle behaviors on vaccine effectiveness against severe COVID-19 in Chile: A matched case-double control study.

World Health Organization approved vaccines have demonstrated relatively high protection against moderate to severe COVID-19. Prospective vaccine effectiveness (VE) designs with first-hand data and population-based controls are nevertheless rare. Neighborhood compared to hospitalized controls, may differ in compliance to non-pharmacuetical interventions (NPI) compliance, which may influence VE results in real-world settings. We aimed to determine VE against COVID-19 intensive-care-unit (ICU) admission using hospital and community-matched controls in a prospective design. We conducted a multicenter, observational study of matched cases and controls (1:3) in adults ≧18 years of age from May to July 2021. For each case, a hospital control and two community controls were matched by age, gender, and hospital admission date or neighborhood of residence. Conditional logistic regression models were built, including interaction terms between NPIs, lifestyle behaviors, and vaccination status; the model's β coefficients represent the added effect these terms had on COVID-19 VE. Cases and controls differed in several factors including education level, obesity prevalence, and behaviors such as compliance with routine vaccinations, use of facemasks, and routine handwashing. VE was 98·2% for full primary vaccination and 85·6% for partial vaccination when compared to community controls, and somewhat lower, albeit not significantly, compared to hospital controls. A significant added effect to vaccination in reducing COVID-19 ICU admission was regular facemask use and VE was higher among individuals non-compliant with the national vaccine program, and/or tonroutine medical visits during the prior year. VE against COVID-19 ICU admission in this stringent prospective case-double control study reached 98% two weeks after full primary vaccination, confirming the high effectiveness provided by earlier studies. Face mask use and hand washing were independent protective factors, the former adding additional benefit to VE. VE was significantly higher in subjects with increased risk behaviors.

Impact of Breast Feeding On Diarrhea and Pneumonia Among Vaccinated Children: Single Center Study

The best way to give babies the nutrition they need to grow and develop is through breast milk. Objective: To assess the combine effect of breast feeding, Rota virus vaccine and Pneumococcal vaccine on frequency of Diarrhea and Pneumonia in children less than 5 years of age. Methods: A descriptive cross-sectional study conducted at Department of Pediatrics at Darul sehat hospital, Karachi. Participants were selected by convenience sampling and interview-based questionnaire was used. 196 Participants were interviewed which included mothers of infant and children from 6 months to 5 years of age, who received complete or partial vaccination according to Expanded program of Immunization (EPI) schedule with information on history of diarrhea and pneumonia. Infant and children with bloody diarrhea were excluded. Results: Among the 196 participants, 152 (77.6%) children received breast feed,72(47.4%) children received two doses of Rota vaccine and 128 (84.2%) children received three doses of Pneumococcal vaccines. Significant impact was seen with breast feeding and Rota vaccine on the frequency of diarrhea with p value of 0.0001. Breastfeeding and the pneumococcal vaccine both had a similar potent effect on the prevalence of pneumonia, with a p-value of 0.006. Conclusions: Our study highlights the importance of breast feeding in vaccinated children, with incidence of diarrhea in breastfed, vaccinated children decreased to (32%), compared to 93% in non-breastfed, unvaccinated infants. Similarly, only 33% of breastfed, vaccinated children developed pneumonia, compared to 85% of unvaccinated, non-breastfed infants.

Protection of hybrid immunity against SARS-CoV-2 reinfection and severe COVID-19 during periods of Omicron variant predominance in Mexico.

With the widespread transmission of the Omicron SARS-CoV-2 variant, reinfections have become increasingly common. Here, we explored the role of immunity, primary infection severity, and variant predominance in the risk of reinfection and severe COVID-19 during Omicron predominance in Mexico. We analyzed reinfections in Mexico in individuals with a primary infection separated by at least 90 days from reinfection using a national surveillance registry of SARS-CoV-2 cases from March 3rd, 2020, to August 13th, 2022. Immunity-generating events included primary infection, partial or complete vaccination, and booster vaccines. Reinfections were matched by age and sex with controls with primary SARS-CoV-2 infection and negative RT-PCR or antigen test at least 90 days after primary infection to explore reinfection and severe disease risk factors. We also compared the protective efficacy of heterologous and homologous vaccine boosters against reinfection. We detected 231,202 SARS-CoV-2 reinfections in Mexico, most occurring in unvaccinated individuals (41.55%). Over 207,623 reinfections occurred during periods of Omicron (89.8%), BA.1 (36.74%), and BA.5 (33.67%) subvariant predominance and a case-fatality rate of 0.22%. Vaccination protected against reinfection, without significant influence of the order of immunity-generating events and provided >90% protection against severe reinfections. Heterologous booster schedules were associated with ~11% and ~ 54% lower risk for reinfection and reinfection-associated severe COVID-19, respectively, modified by time-elapsed since the last immunity-generating event, when compared against complete primary schedules. SARS-CoV-2 reinfections increased during Omicron predominance. Hybrid immunity provides protection against reinfection and associated severe COVID-19, with potential benefit from heterologous booster schedules.

Health care workers' reactions to the newly introduced hepatitis B vaccine in Kalulushi, Zambia: Explained using the 5A taxonomy

Hepatitis B virus (HBV) is highly infectious and deadly disease that is transmitted through blood and body fluids. Health care workers (HCWs) have a high risk of contracting HBV in health care settings, the Hep-B vaccine one of the recommended prevention intervention/tools. However, uptake of the vaccine among HCWs remains low in Sub-Saharan Africa. We aimed to explore the barriers and facilitators to uptake of the vaccine offered free of charge to HCWs and nursing students in Kalulushi district, Copperbelt Province of Zambia. A total of 29 in-depth interviews (IDIs), either in person or via telephone, with participants before and after they received the vaccines were used to collect the data. We analysed the barriers and facilitators to full or partial vaccination using Penchasky and Thomas's (1981) 5A's (Access, Affordability, Awareness, Acceptance and Activation) taxonomy framework for vaccine hesitancy. All participants had access to the vaccine, and it was free of charge, making it affordable. Regarding awareness, all participants were aware of HBV infection as an occupational hazard, however, HCWs felt that more sensitization would be needed to increase awareness and knowledge of the vaccine. Acceptability of the vaccine was high among all completers and some non-completers as they felt it was safe and offered them protection. One non-completer felt coerced to accept the first dose due to supervisor expectations and would have preferred to have been given more time to decide. Most felt that vaccination should be compulsory for HCWs. Lastly, activation (vaccine uptake) among non-completers was hindered by late or no notification of appointments as the main reason for not completing the full vaccination schedule. HCWs advised that for countrywide roll-out, at least one weeks' notification would be necessary for HCWs to plan and be mentally prepared to be at their workstations when the vaccination is taking place. The need to offer the vaccine free of charge locally to ensure easy access and affordability is essential to increase vaccine uptake. Vaccination policies and guidelines for health workers, ongoing training and knowledge sharing are required. Involving trained champions in the facility can also help encourage HCWs to get vaccinated.

Retrospective Analysis of Vaccination Status and Predominant Viral Variants in Patients Hospitalized with COVID-19 in Reus, Spain.

SARS-CoV-2 infection in already-vaccinated individuals is still possible and may require hospitalization. The aim of the present study was to evaluate the clinical evolution of patients with COVID-19 admitted to a public hospital. The outcomes were assessed in relation to the predominant viral variant and the vaccination status. This retrospective study was performed on 1295 COVID-19-positive patients who attended a 352-bed university hospital between 2021 and 2022. Clinical variables and vaccination status were recorded. Of the patients, 799 had not been vaccinated (NV, 61.7%), 449 were partially vaccinated (PV, 34.7%), and 47 were completely vaccinated (CV, 3.6%). The mean age of the CV patients was significantly higher than that of PV and NV. Additionally, they had higher percentages of chronic diseases. The outcomes depended on age but not on vaccination status. There were 209 patients admitted during the Omicron-infection period, of whom 70 (33.5%) were NV, 135 (64.6%) were PV, and 4 (1.9%) were CV. In conclusion, correct vaccination greatly reduces the risk of acquiring severe COVID-19. Partial vaccination does not guarantee protection of the population. This highlights the need for continuous vaccination promotion with all recommended doses, while also investigating alternative treatments for those patients who do not respond to the vaccines.

Impact of inactivated COVID-19 vaccines on lung injury in B.1.617.2 (Delta) variant-infected patients

BackgroundChest computerized tomography (CT) scan is an important strategy that quantifies the severity of COVID-19 pneumonia. To what extent inactivated COVID-19 vaccines could impact the COVID-19 pneumonia on chest CT is not clear.MethodsThis study recruited 357 SARS-COV-2 B.1.617.2 (Delta) variant-infected patients admitted to the Second Hospital of Nanjing from July to August 2021. An artificial intelligence-assisted CT imaging system was used to quantify the severity of COVID-19 pneumonia. We compared the volume of infection (VOI), percentage of infection (POI) and chest CT scores among patients with different vaccination statuses.ResultsOf the 357 Delta variant-infected patients included for analysis, 105 were unvaccinated, 72 were partially vaccinated and 180 were fully vaccinated. Fully vaccination had the least lung injuries when quantified by VOI (median VOI of 222.4 cm3, 126.6 cm3 and 39.9 cm3 in unvaccinated, partially vaccinated and fully vaccinated, respectively; p < 0.001), POI (median POI of 7.60%, 3.55% and 1.20% in unvaccinated, partially vaccinated and fully vaccinated, respectively; p < 0.001) and chest CT scores (median CT score of 8.00, 6.00 and 4.00 in unvaccinated, partially vaccinated and fully vaccinated, respectively; p < 0.001). After adjustment for age, sex, comorbidity, time from illness onset to hospitalization and viral load, fully vaccination but not partial vaccination was significantly associated with less lung injuries quantified by VOI {adjust coefficient[95%CI] for “full vaccination”: − 106.10(− 167.30,44.89); p < 0.001}, POI {adjust coefficient[95%CI] for “full vaccination”: − 3.88(− 5.96, − 1.79); p = 0.001} and chest CT scores {adjust coefficient[95%CI] for “full vaccination”: − 1.81(− 2.72, − 0.91); p < 0.001}. The extent of reduction of pulmonary injuries was more profound in fully vaccinated patients with older age, having underlying diseases, and being female sex, as demonstrated by relatively larger absolute values of adjusted coefficients. Finally, even within the non-severe COVID-19 population, fully vaccinated patients were found to have less lung injuries.ConclusionFully vaccination but not partially vaccination could significantly protect lung injury manifested on chest CT. Our study provides additional evidence to encourage a full course of vaccination.

COVID-19 Vaccination Among Healthcare Workers: Trend and Protection in a Tertiary Care Hospital in Northern India.

Background Coronavirus disease 2019 (COVID-19) is an infectiousdisease that poses health risks to everyone exposed to the virus and frontline healthcare workers (HCWs) are at very high risk. COVID-19 vaccines have been developed to offer protection from the disease and reduce the severity of illness. Objective This questionnaire-based cross-sectional survey aimed to determine COVID-19 vaccination trends and protection among HCWs in a dedicated COVID-19 tertiary care hospital in Northern India. Methods A printout of the questionnaire was distributed. Part 1 of the questionnaire included voluntary consent and demographics information, and part 2 dealt with COVID-19 vaccination, COVID-19 illness, and post-vaccination illness. The outcomes of the study comprised trends and protection offered by COVID-19 vaccination, post-vaccination side-effects, and reasons for vaccine hesitancy. The responses were analyzed using Stata version 15.0. Results: A total of 256 HCWs were approached to take the questionnaire, out of whom 241 consented to participate in the survey. One-hundred and fifty-five (64.3%) of these HCWs were fully vaccinated, 53 (21.9%) were partially vaccinated, and 33 (13.7%) were non-vaccinated. The overall rate of infection was 45.64% (110/241). The rate of infection was 58.18% among non-vaccinated HCWs, 21.81% after partial vaccination, and 20% after full vaccination. The odds of infection among vaccinated versus non-vaccinated HCWs was 0.338 (95% CI: 0.224 to 0.512; P<0.001). The overall hospitalization rate among infected HCWs was 6.36% and there was no incidence of hospitalization among fully vaccinated HCWs. Conclusions: Vaccination was shown to reduce the rates of infection and hospitalization among HCWs. A sizeable number of HCWs remained unvaccinated due to either recent COVID-19 infection or apprehension about vaccine-related side-effects.

Population-Level Effectiveness of an Inactivated Whole-Virion COVID-19 Vaccine: A Test Negative Case-Control Study in the Dominican Republic.

A continuing nationwide vaccination campaign began in the Dominican Republic on February 16, 2021 to prevent severe consequences of acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. Estimates of vaccine effectiveness under real-world conditions are needed to support policy decision making and inform further vaccine selection. We conducted a test-negative case-control study to assess the real-world effectiveness of nationwide coronavirus disease 2019 (COVID-19) vaccination program using an inactivated vaccine (CoronaVac) on preventing symptomatic SARS-CoV-2 infections and hospitalizations from August to November 2021 in the Dominican Republic. Participants were recruited from 10 hospitals in 5 provinces to estimate the effectiveness of full immunization (≥14 days after receipt of the second dose) and partial immunization (otherwise with at least 1 dose ≥14 days after receipt of the first dose). Of 1078 adult participants seeking medical care for COVID-19-related symptoms, 395 (36.6%) had positive polymerase chain reaction (PCR) tests for SARS-CoV-2; 142 (13.2%) were hospitalized during 15 days of follow up, including 91 (23%) among 395 PCR-positive and 51 (7.5%) among 683 PCR-negative participants. Full vaccination was associated with 31% lower odds of symptomatic infection (odds ratio [OR], 0.69; 95% confidence interval [CI], 0.52-0.93) and partial vaccination was associated with 49% lower odds (OR, 0.51; CI, 0.30-0.86). Among 395 PCR-positive participants, full vaccination reduced the odds of COVID-19-related hospitalization by 85% (OR, 0.15; 95% CI, 0.08-0.25) and partial vaccination reduced it by 75% (OR, 0.25; 95% CI, 0.08-0.80); full vaccination was associated with reduced use of assisted ventilation by 73% (OR, 0.27; 95% CI, 0.15-0.49). Given the ancestral and delta viral variants circulating during this study period, our results suggest that the inactivated COVID-19 vaccine offered moderate protection against symptomatic SARS-CoV-2 infections and high protection against COVID-19-related hospitalizations and assisted ventilation. This is reassuring given that, as of August 2022, an estimated 2.6 billion inactivated CoronaVac vaccine doses had been administered worldwide. This vaccine will become a basis for developing multivalent vaccine against the currently circulating omicron variant.

Effectiveness of a Meningococcal Group B Vaccine (4CMenB) in Children

BackgroundIn September 2015, the four-component, protein-based meningococcal serogroup B vaccine (4CMenB; Bexsero) became available for private purchase in Spain.MethodsWe conducted a nationwide matched case–control study to assess the effectiveness of 4CMenB in preventing invasive meningococcal disease in children. The study included all laboratory-confirmed cases of invasive meningococcal disease in children younger than 60 months of age between October 5, 2015, and October 6, 2019, in Spain. Each case patient was matched with four controls according to date of birth and province. 4CMenB vaccination status of the case patients and controls was compared with the use of multivariate conditional logistic regression.ResultsWe compared 306 case patients (243 [79.4%] with serogroup B disease) with 1224 controls. A total of 35 case patients (11.4%) and 298 controls (24.3%) had received at least one dose of 4CMenB. The effectiveness of complete vaccination with 4CMenB (defined as receipt of at least 2 doses, administered in accordance with the manufacturer’s recommendations) was 76% (95% confidence interval [CI], 57 to 87) against invasive meningococcal disease caused by any serogroup, and partial vaccination was 54% (95% CI, 18 to 74) effective. Complete vaccination resulted in an effectiveness of 71% (95% CI, 45 to 85) against meningococcal serogroup B disease. Vaccine effectiveness with at least one dose of 4CMenB was 64% (95% CI, 41 to 78) against serogroup B disease and 82% (95% CI, 21 to 96) against non–serogroup B disease. With the use of the genetic Meningococcal Antigen Typing System, serogroup B strains that were expected to be covered by 4CMenB were detected in 44 case patients, none of whom had been vaccinated.ConclusionsComplete vaccination with 4CMenB was found to be effective in preventing invasive disease by serogroup B and non–serogroup B meningococci in children younger than 5 years of age.

Pregnancy Outcomes in Patients After Completion of the mRNA Coronavirus Disease 2019 (COVID-19) Vaccination Series Compared With Unvaccinated Patients.

To compare frequency of perinatal death between pregnant patients who completed the mRNA coronavirus disease 2019 (COVID-19) vaccination series and unvaccinated patients. This retrospective cohort study included 15,865 pregnant patients who delivered 16,132 newborns after 20 weeks of gestation within a large regional health system between January 1, 2021, and December 31, 2021. Patients who received two doses of mRNA vaccine (Pfizer-BioNTech [BNT162b2] or Moderna [mRNA-1273]) were included in the vaccinated group and were compared with unvaccinated patients. Exclusions included partial vaccination, viral-vector vaccine, major congenital anomalies, and higher-order multiple gestation. Our primary outcome was perinatal death, including stillbirth and neonatal death, which was evaluated by logistic regression. Unadjusted odds ratios and adjusted odds ratios (aORs) were reported, controlling for age, body mass index (BMI), diabetes, hypertension, smoking, twin gestation, and insurance status. Propensity score matching was also performed. A total of 15,865 patients were included in the final analysis: 2,069 in the vaccination group and 13,796 in the control group. Only 13.0% of the cohort was included in the vaccination group; however, the vaccination rate increased over the course of the study period as the vaccine became more widely available and accepted. Vaccinated patients were older, with higher rates of people of non-Black racial non-Hispanic ethnic backgrounds, people with private insurance, and those with higher BMIs. Vaccination was associated with a lower incidence of perinatal death (0.5% vaccinated group vs 0.8% unvaccinated group, aOR 0.20 0.05-0.88). Vaccination against COVID-19 was also associated with lower rates of preterm delivery (aOR 0.63, 0.48-0.82), neonates with very low birth weight (aOR 0.35, 0.15-0.84), and neonatal intensive care unit (NICU) admission (aOR 0.66, 0.52-0.85). The association between vaccination and lower rates of perinatal death was no longer significant after propensity score matching. In a large retrospective cohort study, receipt of the primary mRNA COVID-19 vaccination series was associated with a lower rate of several adverse pregnancy outcomes, including perinatal death, preterm delivery, neonates with very low birth weight, and NICU admission. Although the decreased rates of perinatal death did not remain significant after propensity score matching, there was evidence of directional benefit for vaccinated patients.

COVID-19 vaccination improved outcomes in the treatment of geriatric hip fractures between December 2020 and January 2022.

Geriatric hip fracture patients are at high risk for perioperative morbidity and mortality from COVID-19. This study analyses the impact of COVID-19 vaccination on geriatric hip fracture outcomes. We hypothesise that having the COVID-19 vaccine improves outcomes for geriatric patients treated for hip fracture. Between December 2020 and January 2022, 506 patients treated for hip fracture were analysed for demographics, hospital quality measures, and outcomes. Patients were grouped according to vaccine series administration status. During the study period, there were 329 (65%) unvaccinated patients (NV), 14 (3%) partially vaccinated (PV) patients, 138 (27%) fully vaccinated (FV) patients, and 25 (5%) patients received a booster shot (BV). Variables were compared using chi square, independent sample t-tests or ANOVA as appropriate. Multivariable logistic regression was used to independently assess the impact of vaccination. The rate of minor complications decreased if any vaccination status was achieved (NV: 37.99%, PV: 21.34%, FV: 28.26%, BV: 20.00%; p = 0.054). Vaccinated patients had a decreased need for Intensive Care Unit (ICU) level care (NV: 14.89%, PV: 7.14%, FV: 5.80%, BV: 8.00%; p = 0.038). There were no differences in inpatient or 30-day mortality, major complications, length of stay, home discharge, or readmission within 30 or 90 days. Vaccination against COVID-19 was independently protective against the need for ICU level care. Additionally, female gender and vaccination against COVID-19 decreased the rate of minor complications. Older age and higher comorbidity burden increased the rate of minor complications. In the hip fracture population, vaccination against COVID-19 was protective against the need for ICU level care and decreased overall minor complications. Larger studies are needed to determine if vaccination decreases mortality in this population. These findings have resource allocation implications including ICU bed availability during pandemics and patient outreach to improve vaccination status.

Vaccination effects on post-infection outcomes in the Omicron BA.2 outbreak in Shanghai

ABSTRACT Omicron and its sublineages are currently predominant and have triggered epidemiological waves of SARS-CoV-2 around the world due to their high transmissibility and strong immune escape ability. Vaccines are key measures to control the COVID-19 burden. Omicron BA.2 caused a large-scale outbreak in Shanghai since March 2022 and resulted in over 0.6 million laboratory-confirmed infections. The vaccine coverage of primary immunization among residents aged 3 years and older in Shanghai exceeded 90%, and inactivated COVID-19 vaccines were mainly delivered. In the context of high vaccine coverage, we conducted a cohort study to assess vaccine effects on reducing the probability of developing symptoms or severity of disease in infections or nonsevere cases. A total of 48,243 eligible participants were included in this study, the majority of whom had asymptomatic infections (31.0%) and mild-to-moderate illness (67.9%). Domestically developed COVID-19 vaccines provide limited protection to prevent asymptomatic infection from developing into mild-to-moderate illness and durable protection to prevent nonsevere illness from progressing to severe illness caused by Omicron BA.2. Partial vaccination fails to provide effective protection in any situation. The level of vaccine effects on disease progression in the elderly over 80 years old was relatively lower compared with other age groups. Our study results added robust evidence for the vaccine performance against Omicron infection and could improve vaccine confidence.

COVID-19 vaccine hesitancy between family decision-makers and non-decision-makers among college teachers

Background Teachers with high educational levels significantly impact the health-related knowledge and attitudes of young students and their family members. This study aimed to investigate the coronavirus disease 2019 (COVID-19) vaccine hesitancy and associated factors, and compare the differences between decision-makers and non-decision-makers among college teachers. Methods A cross-sectional online survey was administered across mainland China from 4 to 7 August 2021. Overall, 251 college teachers were included using snowball sampling. A multivariable logistic regression model was applied to explore the association between decision-makers and hesitancy to receive a COVID-19 vaccine. Results Overall, 42.2% of the teachers were hesitant to being vaccinated against COVID-19. The hesitancy rate was lower among primary decision-makers than that among non-decision-makers (34.8% vs. 60.3%, p < .001). Primary decision-makers were less hesitant regarding COVID-19 vaccination than non-decision-makers (OR = 0.37, 95% CI 0.20–0.70); remarkably, whereas those engaged in nursing education versus non-medical related professional education (OR = 2.67, 95% CI 1.29–5.49), and partial versus full-course vaccination recipients (OR = 4.48, 95% CI: 1.76–11.42) were more likely to be hesitant regarding COVID-19 vaccination. Conclusion Our findings indicate that a high proportion of college teachers in China are hesitant to receiving COVID-19 vaccination, and that primary decision-makers are less likely to exhibit hesitancy to being vaccinated against COVID-19 than non-decision-makers in their family. Family decision-makers among teachers can be considered a priority for COVID-19 vaccine promotion, thereby enhancing vaccine acceptance among vulnerable populations—including older adults and children—and preventing adverse outcomes. KEY MESSAGES Question: How prevalent is COVID-19 vaccine hesitancy among college teachers? Do differences exist between decision-makers and non-decision-makers? Findings: We found that a substantial proportion of college teachers are hesitant to being vaccinated against COVID-19, and that family decision-makers exhibited a lower hesitancy rate than non-decision-makers. Meaning: Our findings indicate that distinguishing between family decision-makers and non-decision-makers is necessary to facilitate vaccination promotion interventions among college teachers.

Effectiveness of COVID-19 vaccines against SARS-CoV-2 Omicron variants during two outbreaks from March to May 2022 in Quzhou, China

ABSTRACT Limited data are available on the effectiveness of COVID-19 vaccines used in China in real-world outbreaks – especially against Omicron variants in vaccinated individuals. Two outbreaks of SARS-CoV-2 Omicron variants – the first involving the sub-lineage BA.2 and the second the BA.1 variant – occurred in Quzhou. Infected people and their close contacts were divided according to vaccination status: unvaccinated, partially vaccinated, fully vaccinated, and boosted. The Cox proportional-hazard regression model was used to estimate the evolving hazard for vaccinated individuals after their first immunization. 138 people had been infected with the SARS-CoV-2 Omicron BA.2 variant and 13 with the BA.1 variant. Of the 151 infections, 99.34% (150/151) were mild or asymptomatic and 90.07% (136/151) were vaccine breakthrough cases. The total vaccine effectiveness (VE) of partial, full, and booster vaccinations during the two outbreaks was 47.4% (95%CI: 0–93.1%), 28.9% (95%CI: 0–60.2%), and 27.5% (95%CI: 0–58.3%). The VE of booster vaccination against the Omicron BA.1 variant was higher than that for the BA.2 variant. The cumulative hazard began to increase 220 days after the first immunization. The transmissibility of the Omicron BA.2 variant as for BA.1 did not increase in vaccinated individuals; booster vaccination after a primary course substantially increased protection. Our study found that the SARS-CoV-2 Omicron variant caused less severe illness and that the VE of boosters against the Omicron variant was less than 30%. Timely administration of the booster dose was important, especially for individuals aged over 80 years old.

Effectiveness of vero cell inactivated vaccine against severe acute respiratory infections (SARI) in Sibu, Malaysia: A retrospective test-negative design

ABSTRACT The effectiveness of the vero cell inactivated vaccine (CoronaVac®) against severe acute respiratory infection (‎SARI)‎ caused by SARS-CoV-2 in the real world was assessed. A matched test-negative case-control design was employed using the web-based national information system, as well as the hospitalization dataset in Sibu Hospital. Vaccine effectiveness was measured by conditional logistic regression with adjustment for gender, underlying comorbidity, smoking status, and education level. Between 15 March and 30 September 2021, 838 eligible SARI patients were identified from the hospitalization records. Vaccine effectiveness was 42.4% (95% confidence interval [CI]: −28.3 to 74.1) for partial vaccination (after receiving the first dose to 14 days after receiving the second dose), and 76.5% (95% CI: 45.6 to 89.8) for complete vaccination (at 15 days or more after receiving the second dose). This analysis indicated that two doses of CoronaVac® vaccine provided efficacious protection against SARI caused by SARS-CoV-2 in the short term. However, the duration of protection, and performance against new variants need to be studied continuously.