Effect of the 2020/21 season influenza vaccine on SARS-CoV-2 infection in a cohort of Italian healthcare workers

ObjectivesHealthcare workers (HCWs) are a priority group for seasonal influenza vaccination (SIV). The 2020/21 SIV campaign was conducted during the second wave of the COVID-19 pandemic. Vaccines, including SIV, may exert non-specific protective effects on other infectious diseases which may be ascribable to the concept of trained immunity. The aim of this study was to explore the association between 2020/21 SIV and SARS-CoV-2 positivity in a cohort of Italian HCWs.MethodsIn this observational study, a cohort of HCWs employed by a large (ca 5000 employees) referral tertiary acute-care university hospital was followed up retrospectively until the start of the COVID-19 vaccination campaign. The independent variable of interest was the 2020/21 SIV uptake. Both egg-based and cell culture-derived quadrivalent SIVs were available. The study outcome was the incidence of new SARS-CoV-2 infections, as determined by RT-PCR. Multivariable Cox regression was applied in order to discern the association of interest.ResultsThe final cohort consisted of 2561 HCWs who underwent ≥1 RT-PCR test and accounted for a total of 94,445 person-days of observation. SIV uptake was 35.6%. During the study period, a total of 290 new SARS-CoV-2 infections occurred. The incidence of new SARS-CoV-2 was 1.62 (95% CI: 1.22–2.10) and 3.91 (95% CI: 3.43–4.45) per 1000 person-days in vaccinated and non-vaccinated HCWs, respectively, with an adjusted non-proportional hazard ratio of 0.37 (95% CI: 0.22–0.62). E-values suggested that unmeasured confounding was unlikely to explain the association.ConclusionsA lower risk of SARS-CoV-2 infection was observed among SIV recipients.     

Achieving optimal influenza vaccination rates: a survey-based study of healthcare workers in an urban hospital

In the USA, more than 36 000 deaths and 114 000 hospitalisations result from the influenza virus annually. Healthcare workers have been identified as a key source of influenza outbreaks. Despite Centers for Disease Control and Prevention recommendations to vaccinate all healthcare workers, the rate remains low. A survey-based investigation of influenza vaccination rates and related factors was carried out in an urban community teaching medical centre. A total of 570 surveys revealed a 56.5% influenza vaccination rate among participants. Participants who received the vaccine had a significantly higher mean influenza knowledge score compared to those who did not receive the vaccine (P=0.003). Also, a relationship was identified between those who received the vaccine and the perception that the purpose of the vaccine is to prevent patients from being exposed to influenza (P=0.001). Lastly, hospital departments in which managers actively encouraged and facilitated vaccination had higher rates in general.     

Barriers and facilitators to uptake and promotion of influenza vaccination among health care workers in the community in Beijing,China: A qualitative study

BackgroundIn the prevention and control of influenza, it is important for healthcare workers (HCWs) to be vaccinated and recommend influenza vaccines to their patients. However, there is limited evidence on the factors influencing uptake and promotion of influenza vaccination to patients among HCWs in China.MethodsWe conducted in-depth interviews among HCWs in community health centers, including general practitioners (GPs) and preventive health workers (PHWs), during January to February 2017. A total of 21 individuals, purposively selected from six community health centers covering central districts and remote suburbs in Beijing, were interviewed using semi-structured topic guides. Thematic analysis was used to analyze the interviews and coding framework was developed both inductively and deductively.ResultsIdentified factors influencing influenza vaccine uptake included knowledge, perception and recognition, and prior experience of vaccine uptake. All PHWs conservatively recommended influenza vaccine because of concerns about potential patient–doctor disputes. GPs rarely recommended vaccination under their own initiative because vaccine promotion was not their duties. Notably, we found that the division of work was an underlying reason for the different behaviors regarding vaccine uptake and promotion between GPs and PHWs.ConclusionsOur findings highlighted a combination of misconceptions and cognitive biases limiting influenza vaccine uptake among HCWs in China. Our findings indicate that promotion of health education regarding influenza vaccination should be implemented among HCWs. Importantly, the division of work greatly affects the behaviors of HCWs. GPs, who are at the front line in the doctor–patient relationship, have a critical role in influenza vaccination programs.     

SARS-CoV-2 vaccine breakthrough infections in Virginia,January 17, 2021 – June 30, 2021

As COVID-19 vaccines moved from the controlled environment of clinical trials to use in real-world settings, it has been important to evaluate vaccine effectiveness. A retrospective cohort study was designed to identify cases of SARS-CoV-2 infection that occurred between January 17-June 30, 2021 in fully vaccinated Virginia residents. Of the fully vaccinated population of Virginia at the end of the study period (N = 4,271,505), 2445 (0.057 %) were reported to have experienced a vaccine breakthrough infection. Of those, 183 (7.5 %) were reported to have been hospitalized for COVID-19 and 53 (2.2 %) died from COVID-19. There were significant differences in vaccine effectiveness over time between both mRNA vaccines and the Janssen vaccine. Increasing age, pre-existing medical conditions, and male sex were associated with severe outcomes (hospitalization or death). Persons at greater risk for severe outcomes should continue to take precautions to prevent SARS-CoV-2 infection, even if fully vaccinated.     

成年人连续三批次流感裂解疫苗接种的安全性、免疫原性观察

目的 评价流感裂解疫苗安尔来福TM的安全性和免疫原性,考核疫苗生产工艺的稳定性.方法 采用随机双盲设对照的临床试验设计,试验疫苗为连续三个批次的安尔来福TM,以进口疫苗为对照.受试者为566名18～60岁健康成年人,按照4个年龄层随机分配到4个试验组,疫苗含甲1型、甲3型和乙型流感病毒抗原各15 μg.免疫程序为1针,接种后进行30 min即时反应观察以及24、48、72 h的随访观察,免疫前及免疫后第21天采血,将成对血清设盲后进行血凝抑制(HI)抗体检测.结果 受试者以轻度不良反应为主,各试验组发热反应发生率为1.4%～2.8%,组间差异无统计学意义.4个组3个型别HI抗体阳转率均≥80.3%,GMT增长倍数≥11.1,抗体保护率≥93.4%.三个批次安尔来福TM3个型别的HI抗体阳转率、GMT增长倍数及血清抗体保护率均超过欧盟及美国FDA标准.结论 连续三批次安尔来福TM具有良好的免疫原性和安全性,疫苗生产工艺稳定.     

Attitudes and perception of influenza vaccines among older people in Singapore: A qualitative study

BackgroundDespite recommendations for influenza vaccination of people aged 65 and above, uptake rate of influenza vaccines remains low.This study aims to understand barriers and motivators behind older adult’s decision on influenza vaccination.MethodsFace to face interviews with participants aged 65 and above were conducted and audio recorded in Geylang polyclinic in Singapore. Thematic content analysis was used to organise the data.Results15 older adults were interviewed, aged between 66 and 85 years old. 6 were vaccine refusers, 3 defaulters and 6 acceptors.A perceived lack of vulnerability, fear of side effects, and trivialisation of influenza were common reasons for not taking the vaccine. Encouragement from family and friends, travel and previous positive vaccination experiences were motivators for getting vaccinated. Healthcare workers played a role in influencing many of the participants’ decision-making. Common misconceptions included vaccines considered as necessary only before travel and as a cure rather than prevention. Most participants exhibited ambivalence, giving reasons both for and against vaccine uptake.DiscussionMost older adults do not perceive influenza as a potentially serious disease nor trust in influenza vaccines’ efficacy. Misconceptions played a significant role in vaccine decline. Novel findings include the importance of the family unit in decision making, prioritization of chronic health problems over vaccination and misconception that vaccines are only needed when travelling out of country. Healthcare workers and family members appear to be important influencers in the decision making of older adults and should be actively engaged in future health promotion initiatives.     

Delay between COVID-19 complete vaccination and SARS-CoV-2 infection among healthcare workers

ObjectivesHealthcare workers (HCWs), at increased risk of coronavirus disease 2019 (COVID-19) were among the primary targets for vaccination, which became mandatory for them on September 15th, 2021 in France. In November they were confronted to the fifth COVID-19 wave despite excellent vaccine coverage. We aimed to estimate the incidence of SARS-CoV-2 infection after complete vaccination among HCWs with different vaccination schemes, and its determinants.MethodsWe enrolled all HCWs in the university hospital of Rennes, France who had received complete vaccination (two doses of COVID-19 vaccine). The delay from last vaccination dose to SARS-CoV-2 infection was computed. Fitted mixed Cox survival model with a random effect applied to exposure risk periods to account for epidemic variation was used to estimate the determinants of SARS-CoV-2 infection after complete vaccination.ResultsOf the 6674 (82%) HCWs who received complete vaccination (36% BNT162b2, 29% mRNA-1273, and 34% mixed with ChAdOx1 nCoV-19) and were prospectively followed-up for a median of 7.0 [6.3–8.0] months, 160 (2.4%) tested positive for SARS-CoV-2 by RT-PCR. Incidence density of SARS-CoV-2 infection after complete vaccination was 3.39 [2.89–3.96] infections per 1000 person-month. Median time from vaccine completion to SARS-CoV-2 infection was 5.5 [3.2–6.6] months. Using fitted mixed Cox regression with the delay as a time-dependent variable and random effect applied to exposure risk periods, age (P < 0.001) was independently associated with the incidence of SARS-CoV-2 infection. Vaccine schemes were not associated with SARS-CoV-2 infection (P = 0.068). A period effect was significantly associated with the incidence of SARS-CoV-2 infection (P < 0.001).ConclusionsIn this real-world study, incidence of SARS-CoV-2 infection increases with time in fully vaccinated HCWs with no differences according to the vaccination scheme. The short delay between complete vaccination and incident SARS-CoV-2 infection highlights the need for sustained barrier measures even in fully vaccinated HCWs.     

Pandemic influenza A/H1N1 vaccination uptake among health care workers in Qatar: motivators and barriers

Influenza A/H1N1 new vaccine helps control disease spread. Cross-sectional survey was conducted at PHC & Emergency Departments in Qatar to determine influenza A/H1N1 vaccination rate among HCWs and associated factors, 523 HCWs were enrolled. The study showed that 13.4% HCWs received vaccination. Feeling protected strongly influenced vaccination decision (OR = 14.5). Uncertainty about vaccine efficacy and fear of side effects strongly influenced decision to reject the vaccine (OR = 0.3 and 0.2 respectively). Vaccination coverage was very low. The most common barriers were uncertainty about vaccine efficacy and fear of side effects. Health authorities should build message highlighting how the benefit of vaccination outweighs risk.     

The views of key stakeholders around mandatory influenza vaccination of hospital and aged care staff: Examining the current climate in Australia

Background

Healthcare worker (HCW) vaccination against seasonal influenza is considered a key preventative measure within hospitals and aged-care facilities (ACFs) to reduce the risk of transmission and related disease. Despite this, many facilities experience persistently low vaccination coverage rates and mandatory vaccination has been explored as a potential strategy to improve coverage. This study explored the current climate around staff vaccination in Australia from the perspective of opinion leaders and key stakeholders.

Dynamics of antibody titers and cellular immunity among Japanese healthcare workers during the 6 months after receiving two doses of BNT162b2 mRNA vaccine

BackgroundThe antibody titer is known to wane within months after receiving two doses of the Pfizer-BioNTech BNT162b2 mRNA SARS-CoV-2 vaccine. However, knowledge of the cellular immune response dynamics following vaccination is limited. This study to aimed to determine antibody and cellular immune responses following vaccination, and the incidence and determinants of breakthrough infection.MethodsThis prospective cohort study a 6-month follow-up period was conducted among Japanese healthcare workers. All participants received two doses of BNT162b2 vaccine. Anti-SARS-CoV-2 antibody titers and T-cell immune responses were measured in serum samples collected at several timepoints before and after vaccination.ResultsA total of 608 participants were included in the analysis. Antibody titers were elevated 3 weeks after vaccination and waned over the remainder of the study period. T-cell immune responses showed similar dynamics. Six participants without predisposing medical conditions seroconverted from negative to positive on the IgG assay for nucleocapsid proteins, indicating breakthrough SARS-CoV-2 infection. Five of the six breakthrough infections were asymptomatic.ConclusionsBoth humoral and cellular immunity waned within 6 months after BNT162b2 vaccination. The incidence of asymptomatic breakthrough infection within 6 months after vaccination was approximately one percent.UMIN Clinical Trials Registry IDUMIN000043340.     

Immune response to one dose of BNT162b2 mRNA Covid-19 vaccine followed by SARS-CoV-2 infection: An Italian prospective observational study

IntroductionA mass vaccination campaign against SARS-CoV-2 was initiated in European countries on December 27, 2020. This study compared the antibody response in a sample of healthcare workers (HCWs) who, after the first dose of the BNT162b2 mRNA vaccine, were infected with SARS-CoV-2 (infection group) with the response in a control group of HCWs immunized with two doses (vaccine group).MethodsThis two-arm observational cohort study was carried out using routine health surveillance data obtained from HCWs at Bari Policlinico General Hospital (Italy). The antibody response was determined infection group and vaccine group.ResultsAmong the 100 HCWs, 25 (25.0%) were in the infection group and 75 (75.0%) in the full-vaccine group. At the serological evaluation, all of the HCWs tested positive, with a geometric mean titer (GMT) of 7106.8 (95 %CI = 5628.5–8973.4) and a statistically significant difference (p < 0.0001) between the infection group (GMT = 2139.7; 95 %CI = 1310.4–3493.6) and the vaccine group (GMT = 10603.6; 95 %CI = 8698.0–12926.8).DiscussionOur results shed light on the vaccine response of individuals in different risk categories. It also emphasizes the need for the continued use by HCWs of PPE and good practices during the window between the first and second anti-SARS-CoV-2 vaccinations.     

Safety and immunogenicity of a 20-valent pneumococcal conjugate vaccine coadministered with quadrivalent influenza vaccine: A phase 3 randomized trial

IntroductionOlder adults are at increased risk of adverse outcomes from pneumococcal disease and influenza infections. Vaccination is an established strategy for preventing both illnesses. This study evaluated coadministration of 20-valent pneumococcal conjugate vaccine (PCV20) and an adjuvanted quadrivalent inactivated influenza vaccine (QIV).MethodsThis phase 3, randomized, double-blind, multicenter study included 1796 US adults ≥ 65 years of age randomized 1:1 to receive either PCV20 and QIV followed 1 month later by saline (Coadministration group) or QIV and saline followed 1 month later by PCV20 (Separate Administration group). Primary immunogenicity objectives were to show noninferiority of PCV20 and QIV coadministration compared with separate administration of either vaccine based on serotype-specific opsonophagocytic activity (OPA) titers for PCV20 and strain-specific hemagglutination inhibition assay (HAI) titers for QIV. Safety endpoints included local reactions, systemic events, and adverse events (AEs).ResultsNoninferiority for pneumococcal and influenza antibody responses (lower bound 95 % CI of the OPA and HAI geometric mean ratios of > 0.5 and > 0.67, respectively) was shown for the Coadministration group compared with the Separate Administration group for all 20 pneumococcal serotypes and all 4 influenza vaccine strains. Local reactions and systemic events were mostly mild or moderate in severity across groups; injection site pain was the most frequent local reaction, and fatigue was the most frequent systemic event. Mild and moderate fatigue were reported more frequently after PCV20 and QIV coadministration compared with separate administration (mild, 20.0 % vs 10.8 %-12.6 %; moderate, 12.3 % vs 8.4 %-9.6 %); this was not considered clinically significant. AE reporting rates were similar across groups, and no serious AEs were considered vaccination-related.ConclusionsImmune responses after coadministration of PCV20 and QIV were noninferior to separate administration of either vaccine. The PCV20 safety profile was similar when given together with or after QIV. These findings support PCV20 and QIV coadministration.Trial Registration: ClinicalTrials.gov, NCT04526574.     

SARS-CoV-2 infection risk among 77,587 healthcare workers: a national observational longitudinal cohort study in Wales,United Kingdom,April to November 2020

ObjectivesTo better understand the risk of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection among healthcare workers, leading to recommendations for the prioritisation of personal protective equipment, testing, training and vaccination.DesignObservational, longitudinal, national cohort study.SettingOur cohort were secondary care (hospital-based) healthcare workers employed by NHS Wales (United Kingdom) organisations from 1 April 2020 to 30 November 2020.ParticipantsWe included 577,756 monthly observations among 77,587 healthcare workers. Using linked anonymised datasets, participants were grouped into 20 staff roles. Additionally, each role was deemed either patient-facing, non-patient-facing or undetermined. This was linked to individual demographic details and dates of positive SARS-CoV-2 PCR tests.Main outcome measuresWe used univariable and multivariable logistic regression models to determine odds ratios (ORs) for the risk of a positive SARS-CoV-2 PCR test.ResultsPatient-facing healthcare workers were at the highest risk of SARS-CoV-2 infection with an adjusted OR (95% confidence interval [CI]) of 2.28 (95% CI 2.10–2.47). We found that after adjustment, foundation year doctors (OR 1.83 [95% CI 1.47–2.27]), healthcare support workers [OR 1.36 [95% CI 1.20–1.54]) and hospital nurses (OR 1.27 [95% CI 1.12–1.44]) were at the highest risk of infection among all staff groups. Younger healthcare workers and those living in more deprived areas were at a higher risk of infection. We also observed that infection rates varied over time and by organisation.ConclusionsThese findings have important policy implications for the prioritisation of vaccination, testing, training and personal protective equipment provision for patient-facing roles and the higher risk staff groups.     

新型冠状病毒疫苗:现状与展望

新型冠状病毒肺炎的大流行严重威胁人类健康和发展,为应对这一全球性公共卫生事件,多种技术路线的新型冠状病毒疫苗(新冠疫苗)被投入紧急使用.本文介绍了新冠疫苗技术路线,并就新冠疫苗应对多种突变毒株的效力和在高危人群中的使用进行了梳理,发现现有疫苗对突变毒株效力出现了不同程度的下降,提示应关注突变毒株的影响.现有疫苗对高龄,...     

Effectiveness of prevention of SARS-CoV-2 transmission among unvaccinated Italian healthcare workers

Background:We aimed to investigate the association between personal protective equipment (PPE) use and SARS-CoV-2 infection among healthcare workers (HCWs).Methods:We analyzed occupational surveillance contact forms followed by a PCR test notified between March and September 2020 by Italian HCWs. The odds ratios (ORs) and 95% Confidence Intervals (CIs) for positive PCR based on HCWs and contacts characteristics were calculated through multivariable logistic regression models. When multiple contacts were potentially effective for a PCR test, they were weighted by the inverse of their number.Results:Overall, 4,883 contacts reported by 2,952 HCWs were analyzed, and 224 contacts among 144 HCWs had positive PCR. No difference was found according to sex, age, employment, or job title, except for an OR of 0.30 (95%CI 0.11-0.78) for resident physicians, compared to administrative staff. The ORs for use of surgical mask were 0.59 (95%CI=0.40-0.86) for use only by HCW, 0.49 (95%CI=0.22-1.07) only by the infected person, and 0.40 (95%CI=0.27-0.60) by both, compared to use by neither. Use of other PPEs was not associated with infection, while the OR for hand sanitation was 0.61 (95%CI=0.40-0.93). HCWs reporting fever, cough, and asthenia had a higher risk of infection.Conclusions:Use of surgical masks was associated with a 40-60% lower risk of infection, especially when both HCWs and infected individuals used them. Our results quantify the role played by mask use and hand sanitation in preventing SARS-CoV-2 transmission in high-risk circumstances.     

Comparison of the effectiveness and duration of anti-RBD SARS-CoV-2 IgG antibody response between different types of vaccines: Implications for vaccine strategies

Background and objectivesLittle is known about the efficacy and durability of anti-RBD IgG antibodies induced by certain SARS-CoV-2 vaccines. It has been shown that neutralizing antibodies are associated with the protection against re-infection. This study aims to compare the mean titers, duration, and efficacy of generating protective anti-RBD IgG antibody response among recipients of Pfizer/BioNTech, AstraZeneca, Sputnik V, Johnson & Johnson, Moderna, and Sinopharm COVID-19 vaccines. In addition, we aimed to compare the susceptibility of getting COVID-19 breakthrough infections after various types of vaccines.Materials and methodsSamples from 2065 blood bank donors and healthcare workers at King Hussein Cancer Center (KHCC) were collected between February and September 2021. Anti-Spike/RBD IgG levels were measured using Chemiluminescent microparticle-immunoassay (CMIA) (ARCHITECT IgG II Quant test, Abbott, USA).ResultsThe mean titer of anti-RBD IgG levels was significantly diverse among different types of vaccines. The highest titer level was seen in participants who took a third booster vaccine shot, followed by Pfizer/BioNTech, AstraZeneca, and Sinopharm vaccine. The mean titer levels of anti-RBD IgG antibodies in the Pfizer vaccinated group was the highest after vaccination but started to drop after 60 days from vaccination unlike AstraZeneca and Sinopharm vaccine-induced antibodies where the mean titers continued to be stable until 120 days but their levels were significantly lower. Most of the breakthrough infections were among the Sinopharm vaccinated group and these breakthroughs happened at random times for the three main types of vaccines.ConclusionsOur data demonstrate that the mean-titer of anti-RBD IgG levels drop after four months which is the best time to take the additional booster shot from a more potent vaccine type such as mRNA vaccines that might be needed in Jordan and worldwide.     

Appropriateness and preferential use of different seasonal influenza vaccines: A pilot study on the opinion of vaccinating physicians in Italy

In Italy, several types of influenza vaccine are on the market. Available evidence suggests that no single vaccine type is universally appropriate; rather, different types may be more appropriate for different population strata. However, while the concept of appropriateness/preferential use of single vaccines is usually adopted at the central level, little is known about the attitudes of physicians on the matter. A pilot survey of Italian physicians (N?=?372) revealed that most (about 90%) were aware that the available vaccines were different, and that particular vaccines were more appropriate for specific groups. The availability of explicit guidelines on which vaccine to administer to a given population group was deemed desirable by 93.2% of respondents. The results were consistent with the 2018 Italian and UK normative documents, which indicate adjuvanted vaccines as the most appropriate choice for the elderly, and quadrivalent formulations for the younger age-classes. Public health policy implications are discussed.     

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

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