The impact of COVID-19 vaccination delay: A data-driven modeling analysis for Chicago and New York City

BackgroundBy the beginning of December 2020, some vaccines against COVID-19 already presented efficacy and security, which qualify them to be used in mass vaccination campaigns. Thus, setting up strategies of vaccination became crucial to control the COVID-19 pandemic.MethodsWe use daily COVID-19 reports from Chicago and New York City (NYC) from 01-Mar2020 to 28-Nov-2020 to estimate the parameters of an SEIR-like epidemiological model that accounts for different severity levels. To achieve data adherent predictions, we let the model parameters to be time-dependent. The model is used to forecast different vaccination scenarios, where the campaign starts at different dates, from 01-Oct-2020 to 01-Apr-2021. To generate realistic scenarios, disease control strategies are implemented whenever the number of predicted daily hospitalizations reaches a preset threshold.ResultsThe model reproduces the empirical data with remarkable accuracy. Delaying the vaccination severely affects the mortality, hospitalization, and recovery projections. In Chicago, the disease spread was under control, reducing the mortality increment as the start of the vaccination was postponed. In NYC, the number of cases was increasing, thus, the estimated model predicted a much larger impact, despite the implementation of contention measures.The earlier the vaccination campaign begins, the larger is its potential impact in reducing the COVID-19 cases, as well as in the hospitalizations and deaths. Moreover, the rate at which cases, hospitalizations and deaths increase with the delay in the vaccination beginning strongly depends on the shape of the incidence of infection in each city.     

Change in COVID19 outbreak pattern following vaccination in long-term care facilities in Flanders,Belgium

IntroductionLong term care facilities for elderly (LTCFs) in Europe encountered a high disease burden at the start of the COVID-19 pandemic. Therefore, these facilities were the first to receive COVID-19 vaccines in many European countries. A limited COVID-19 vaccine supply early 2021 resulted in a majority of residents and healthcare workers (HCWs) in LTCFs being vaccinated compared to a minority in the general population. This study exploits this imbalance to assess the efficiency of COVID-19 vaccination in containing outbreaks in LTCFs.MethodsExploratory statistics were performed using data from a COVID-19 surveillance system covering all 842 LTCFs in Flanders (the northern region of Belgium). The number and size of COVID-19 outbreaks in LTCFs were compared (1) before and after introducing vaccines and (2) with the status of the pandemic in the general population. Based on individual data from 15 LTCFs, the infection rate and symptoms of vaccinated and unvaccinated residents and HCWs were compared during a COVID-19 outbreak.Results95.8% of the residents and 90.9% of the HCWs in Flemish LTCFs were vaccinated before May 30, 2021. Before vaccine introduction, residents in LTCFs were 10 times more likely to test positive for COVID-19 than the general population of Flanders. This ratio reversed after vaccination. Furthermore, after vaccination fewer and shorter outbreaks were observed involving fewer residents. During these outbreaks, vaccinated and unvaccinated residents were equally likely to test positive, but positive vaccinated residents were less likely to develop severe symptoms. In contrast, unvaccinated HCWs were more likely to test positive.ConclusionIn the first half of 2021, two-dose vaccination was highly efficient in preventing and containing outbreaks in LTCFs, reducing COVID-19 hospitalizations and deaths. The high likelihood of unvaccinated HCWs to be involved in COVID-19 outbreaks in vaccinated LTCFs emphasizes the importance of vaccinating HCWs.     

Projected COVID-19 epidemic in the United States in the context of the effectiveness of a potential vaccine and implications for social distancing and face mask use

BackgroundMultiple candidates of COVID-19 vaccines have entered Phase III clinical trials in the United States (US). There is growing optimism that social distancing restrictions and face mask requirements could be eased with widespread vaccine adoption soon.MethodsWe developed a dynamic compartmental model of COVID-19 transmission for the four most severely affected states (New York, Texas, Florida, and California). We evaluated the vaccine effectiveness and coverage required to suppress the COVID-19 epidemic in scenarios when social contact was to return to pre-pandemic levels and face mask use was reduced. Daily and cumulative COVID-19 infection and death cases from 26th January to 15th September 2020 were obtained from the Johns Hopkins University Coronavirus resource center and used for model calibration.ResultsWithout a vaccine (scenario 1), the spread of COVID-19 could be suppressed in these states by maintaining strict social distancing measures and face mask use levels. But relaxing social distancing restrictions to the pre-pandemic level without changing the current face mask use would lead to a new COVID-19 outbreak, resulting in 0.8–4 million infections and 15,000–240,000 deaths across these four states over the next 12 months. Under this circumstance, introducing a vaccine (scenario 2) would partially offset this negative impact even if the vaccine effectiveness and coverage are relatively low. However, if face mask use is reduced by 50% (scenario 3), a vaccine that is only 50% effective (weak vaccine) would require coverage of 55–94% to suppress the epidemic in these states. A vaccine that is 80% effective (moderate vaccine) would only require 32–57% coverage to suppress the epidemic. In contrast, if face mask usage stops completely (scenario 4), a weak vaccine would not suppress the epidemic, and further major outbreaks would occur. A moderate vaccine with coverage of 48–78% or a strong vaccine (100% effective) with coverage of 33–58% would be required to suppress the epidemic. Delaying vaccination rollout for 1–2 months would not substantially alter the epidemic trend if the current non-pharmaceutical interventions are maintained.ConclusionsThe degree to which the US population can relax social distancing restrictions and face mask use will depend greatly on the effectiveness and coverage of a potential COVID-19 vaccine if future epidemics are to be prevented. Only a highly effective vaccine will enable the US population to return to life as it was before the pandemic.     

Catch-up vaccination campaign in children between 6 and 8 years old during COVID-19 pandemic: The experience in a COVID hub in Milan,Italy

BackgroundCOVID-19 has led to disruption in routine immunization programs around the world. Effective strategies need to be developed to address the decline in vaccine coverage to avoid preventable disease outbreaks. Our study reports a 4-days campaign for the catching-up of missed vaccinations in children aged between 6 and 8 years, in Milan, Italy.MethodsThe catch-up vaccination campaign (21st-24th of September 2021) involved children born in 2013, 2014 and 2015. These cohorts, if not already immunized, received the fourth dose of the Diphtheria-Tetanus-acellular Pertussis and Poliomyelitis vaccination (DTaPP4), the second dose of the Measles-Mumps and Rubella vaccination (MMR2) and Chickenpox, according to the Italian vaccine schedule.Results3,943 letters were sent to children with a missing vaccination. 1,315 children, 33% of expected, were vaccinated during the campaign. The 2015 cohort was the one that benefited most from the initiative, 955 children were vaccinated for a total of 1,864 doses administered. This has led to a significant increase of 20.0 percentage points (p.p.) in vaccination coverages for the fourth dose of DTaPP and the second dose of MMR. 214 children for the 2014 cohort and 146 for the 2013 cohort were vaccinated during the following days, these cohorts have been already called previously therefore the participation in the campaign and consequently the increase in vaccination coverages were less substantial.ConclusionsThis experience has demonstrated that a mass vaccination campaign could be a useful tool in catch-up strategies, even during the pandemic. It should be part of a bigger immunization program strategy that also includes efforts to simultaneously strengthen routine immunization services. With the appropriate organizational improvements, this initiative could pave the way for future successful campaigns involving different age groups and vaccinations.     

Impact of COVID-19 immunisation on COVID-19 incidence,hospitalisations, and deaths by age group in Germany from December 2020 to October 2021

BackgroundUtilising national surveillance data, we investigated the impact of the COVID-19 immunisation campaign on COVID-19 morbidity and mortality between December/2020 and October/2021 in Germany.MethodsWe compared patterns in immunisation coverage, incidence, hospitalisations, and deaths among 12–17, 18–59, and 60+ year-olds and examined these patterns within the context of anti-pandemic measures.ResultsCOVID-19 incidence increased in all age groups following the end of lockdown restrictions in March/2021, but as Germany experienced successive peaks in incidence, age groups with higher immunisation coverage experienced successively smaller peaks. Notwithstanding corresponding increases during periods of higher incidence, among those aged 60+ years, COVID-19 related hospitalisations and deaths declined considerably as immunisation coverage increased, despite circulation of virus variants known to cause more severe illness.ConclusionAlthough ecological in nature, this study allows us to demonstrate clear patterns of decline in COVID-19 morbidity and mortality in Germany during the course of the immunisation campaign.     

COVID-19 vaccine perceptions and hesitancy amongst parents of school-aged children during the pediatric vaccine rollout

BackgroundThe United States has the highest number of total cases and deaths due to coronavirus disease 2019 (COVID-19) worldwide (Johns Hopkins COVID Dashboard, 2021). Despite COVID-19 vaccine availability, uptake in the United States has been slow and vaccine hesitancy has been a significant barrier to achieving widespread vaccine uptake. Understanding determinants of vaccine acceptance is essential to implement successful population health interventions to increase COVID-19 vaccination.MethodsWe developed an anonymous cross-sectional parent survey to assess factors associated with parent and child COVID-19 vaccine acceptance and hesitancy during the initial pediatric vaccine rollout amongst adolescents 16 years +. The survey was sent via email to 25,308 parents registered to the Alachua County Public School System in May 2021 and remained active until July 2021.FindingsThere were a total of 2,620 survey responses. Overall, 31.5 % of parents with children ages 16 years + reported their child had received the COVID-19 vaccine, 65.2 % reported their (eligible) child had not received the vaccine, and 3.3 % reported their child was scheduled for the vaccine. A majority of parents (60.9 %) reported they planned to vaccinate all of their children once the COVID-19 vaccine was available for their children’s age. COVID-19 vaccine uptake in adolescents ages 16 + reported by Hispanic and White parents was two times higher than that reported by Black parents. Parent COVID-19 and influenza vaccine uptake were associated with increased child COVID-19 vaccination. The most commonly reported reasons why parents chose not to have their child vaccinated against COVID-19 were concerns about long–term negative side effects (75.7 %) and a negative reaction (56.5 %). Medical providers were reported as the most trusted source of information.ConclusionOur study provides insight into determinants of vaccine acceptance, vaccine hesitancy, and trusted sources of information that may be helpful to develop targeted interventions to increase youth COVID-19 vaccination.     

COVID-19 vaccine uptake in mental healthcare users: Czech nationwide register study

BackgroundThe excessive covid-related mortality of psychiatric patients was reduced by vaccination. The vaccine uptake in patients diagnosed with different mental health disorders is, however, not fully described.AimsA nationwide, record-based retrospective cross-sectional study examines the effect of substance use, psychotic, affective, anxiety, and personality disorders on COVID-19 vaccination rates in August and December 2021. Further, it quantifies the effect of receiving mental healthcare on vaccine uptake.MethodsThe COVID-19 vaccine rates of mental healthcare users in August and December 2021 were examined using logistic regression models adjusted for sex and age on a sample of 7,235,690 adult inhabitants of the Czech Republic. The probability of vaccine uptake in the week following mental healthcare appointment or hospitalization on any day in the fall 2021 was compared to the general probability of getting vaccinated during that week.ResultsThe vaccination rate in August 2021 was related to history of hospitalization due to substance use (OR = 0.71), personality (OR = 0.87), psychotic (OR = 0.92), and anxiety (OR = 1.15) disorders, while mood disorders had no effect (OR = 1.00). Compared to general population, mental healthcare users were undervaccinated in August but not in December 2021. Vaccine uptake was low in those with history of psychiatric hospitalizations but higher in those utilizing inpatient or outpatient mental healthcare recently, predominantly for affective disorders. Increased vaccine uptake was observed following utilization of mental healthcare as well as in those with repeated psychiatric hospitalizations.ConclusionsThe vaccination rates of mental healthcare users relative to general population largely differ across nosological categories and during the vaccination campaign. Psychiatrists were successful in promoting vaccination against COVID-19.     

Modelling optimal vaccination strategies against COVID-19 in a context of Gamma variant predominance in Brazil

IntroductionBrazil experienced moments of collapse in its health system throughout 2021, driven by the emergence of variants of concern (VOC) combined with an inefficient initial vaccination strategy against Covid-19.ObjectivesTo support decision-makers in formulating COVID-19 immunization policy in the context of limited vaccine availability and evolving variants over time, we evaluate optimal strategies for Covid-19 vaccination in Brazil in 2021, when vaccination was rolled out during Gamma variant predominance.MethodsUsing a discrete-time epidemic model we estimate Covid-19 deaths averted, considering the currently Covid-19 vaccine products and doses available in Brazil; vaccine coverage by target population; and vaccine effectiveness estimates. We evaluated a 5-month time horizon, from early August to the end of December 2021. Optimal vaccination strategies compared the outcomes in terms of averted deaths when varying dose intervals from 8 to 12 weeks, and choosing the minimum coverage levels per age group required prior to expanding vaccination to younger target populations. We also estimated dose availability required over time to allow the implementation of optimal strategies.ResultsTo maximize the number of averted deaths, vaccine coverage of at least 80 % should be reached in older age groups before starting vaccination into subsequent younger age groups. When evaluating varying dose intervals for AZD1222, reducing the dose interval from 12 to 8 weeks for the primary schedule would result in fewer COVID-19 deaths, but this can only be implemented if accompanied by an increase in vaccine supply of at least 50 % over the coming six-months in Brazil.ConclusionCovid-19 immunization strategies should be tailored to local vaccine product availability and supply over time, circulating variants of concern, and vaccine coverage in target population groups. Modelling can provide valuable and timely evidence to support the implementation of vaccination strategies considering the local context, yet following international and regional technical evidence-based guidance.     

COVID-19 vaccine website accessibility dashboard

BackgroundThe COVID-19 pandemic has exacerbated historical inequities for people with disabilities including barriers in accessing online information and healthcare appointment websites. These barriers were brought to the foreground during the vaccine rollout and registration process.ObjectiveThis cross-sectional study aimed to examine accessibility of U.S. state and territory COVID-19 information and registration centralized websites.MethodsThe Johns Hopkins Disability Health Research Center created a COVID-19 Vaccine Dashboard compiling COVID-19 information and vaccine registration web pages from 56 states and territories in the United States (U.S.) reviewed between March 30 through April 5, 2021 and analyzed accessibility using WAVE Web Accessibility Evaluation Tool (WAVE). WAVE identifies website accessibility barriers, including insufficient contrast, alternative text, unlabeled buttons, total number of errors, and error density. Web pages were ranked and grouped into three groups by number of errors, creating comparisons between states on accessibility barriers for people with disabilities.ResultsAll 56 U.S states and territories had COVID-19 information web pages and 29 states had centralized state vaccine registration web pages. Total errors, error density, and alert data were utilized to generate accessibility scores for each web page, the median score was 259 (range = 14 to 536 and IQR = 237) for information pages, and 146 (range = 10 to 281 and IQR = 105) for registration pages.ConclusionsThese results highlight barriers people with disabilities may encounter when accessing information and registering for the COVID-19 vaccine, which underscore inequities in the pandemic response for the disability community and elevate the need to prioritize accessibility of public health information.     

Factors Driving the Popularity and Virality of COVID-19 Vaccine Discourse on Twitter: Text Mining and Data Visualization Study

BackgroundCOVID-19 vaccination is considered a critical prevention measure to help end the pandemic. Social media platforms such as Twitter have played an important role in the public discussion about COVID-19 vaccines.ObjectiveThe aim of this study was to investigate message-level drivers of the popularity and virality of tweets about COVID-19 vaccines using machine-based text-mining techniques. We further aimed to examine the topic communities of the most liked and most retweeted tweets using network analysis and visualization.MethodsWe collected US-based English-language public tweets about COVID-19 vaccines from January 1, 2020, to April 30, 2021 (N=501,531). Topic modeling and sentiment analysis were used to identify latent topics and valence, which together with autoextracted information about media presence, linguistic features, and account verification were used in regression models to predict likes and retweets. Among the 2500 most liked tweets and 2500 most retweeted tweets, network analysis and visualization were used to detect topic communities and present the relationship between the topics and the tweets.ResultsTopic modeling yielded 12 topics. The regression analyses showed that 8 topics positively predicted likes and 7 topics positively predicted retweets, among which the topic of vaccine development and people’s views and that of vaccine efficacy and rollout had relatively larger effects. Network analysis and visualization revealed that the 2500 most liked and most retweeted retweets clustered around the topics of vaccine access, vaccine efficacy and rollout, vaccine development and people’s views, and vaccination status. The overall valence of the tweets was positive. Positive valence increased likes, but valence did not affect retweets. Media (photo, video, gif) presence and account verification increased likes and retweets. Linguistic features had mixed effects on likes and retweets.ConclusionsThis study suggests the public interest in and demand for information about vaccine development and people’s views, and about vaccine efficacy and rollout. These topics, along with the use of media and verified accounts, have enhanced the popularity and virality of tweets. These topics could be addressed in vaccine campaigns to help the diffusion of content on Twitter.     

Evaluation of mortality risk after COVID-19 vaccination,Utah 2021

IntroductionIn order to evaluate trends in death after COVID-19 vaccination we analyzed the timing of death relative to vaccination date and the causes of death in vaccinated Utahns in 2021.MethodsWe matched people in the Utah immunization registry with documented COVID-19 vaccinations between December 18, 2020 and December 31, 2021 to Utah’s 2021 vital statistics death records. Vaccinated people were categorized as having one, two, or ≥ three COVID-19 vaccine doses in a time-updated metric. We examined crude mortality rates by dosing groups in two-week intervals for all deaths, and by COVID-19 versus non-COVID-19 causes, within the 44 weeks following receipt of the most recent vaccine.ResultsWe identified 2,072,908 individuals who received at least one dose of COVID-19 vaccine of whom 10,997 died in 2021. Only 17.5 % of the total vaccinated population was age 65+, while 80.9 % of those who died were over 65. In the four weeks following the first or second vaccination, all-cause mortality was low and then stabilized for the remainder of the evaluation period at a bi-weekly average of 33.0 and 39.0 deaths/100,000 people for one and two doses, respectively. Typical seasonal variation in death was observed among those with two doses. Small sample size precluded analysis of those with ≥ three doses, but trends were similar.ConclusionsMortality rates in the 44 weeks following the COVID-19 vaccination did not show trends suggesting an increase in mortality related to COVID-19 vaccination, reinforcing the safety of COVID-19 vaccines. This represents an accessible approach for local evaluation.     

Confidence and Hesitancy During the Early Roll-out of COVID-19 Vaccines Among Black,Hispanic, and Undocumented Immigrant Communities: a Review

Black and Hispanic Americans have been hardest hit with COVID-19 infections, hospitalizations, and deaths, yet during the first several months of vaccine roll-out they had the lowest level of vaccine uptake. Primarily, our research on vaccine hesitancy focused on skepticism around the vaccine itself and its roll-out. Our search strategy used PUBMED and Google with a prescribed set of definitions and search terms for two reasons: there were limited peer-reviewed studies during early period of roll-out and real-time perspectives were crucially needed. Literature searches occurred in April 2021and covered September 2020-April 2021. Analyses included expert opinion, survey results and qualitative summaries. Overall, for the general U.S. population, there was considerable hesitancy initially that remained high during the early roll-out. The general population expressed concerns over the speed of vaccine development (“warp speed”), confidence in the competence of government being involved in the development of vaccines and general mistrust of government. Among Black and Hispanic Americans, hesitancy was further expressed as mistrust in the medical establishment that was related to past and current medical mistreatment. Undocumented immigrants worried about access to insurance and possible deportation. These results on confidence in the vaccine early during vaccine roll-out suggest diverse reasons that influence a person’s decision to vaccinate or not. Additional barriers to vaccine uptake include complacency and access. To ensure health equity, particularly to address disparities in morbidity and mortality, vaccine hesitancy needs to be acknowledged and addressed as COVID-19 vaccine roll-out continues, and these observations calls for conscious planning to address these issues early with future health crises.

The Coronavirus Disease 2019 (COVID-19) pandemic has had a national impact in the USA. An early observation that has remained throughout the course of the COVID-19 pandemic has been the higher rates of test positivity[¹], hospitalizations, and deaths among Black and Hispanic Americans and American Indian and Alaskan Natives compared to Whites and Asians [^2–10]. While disparities have been documented across different stages of the pandemic, data updated through April 23, 2021 showed a decline in relative risk by racialized grouping and ethnicity with Whites as the reference racial group; this has been partly attributed to an increase in COVID-19 vaccination availability but a plateau in vaccine over time among Whites.Reasons for the disparities in morbidity and mortality have been examined. Two early hypotheses were forwarded to explain higher rates of outcomes among Black, Hispanic, and American Indian/Native Alaskan persons. Firstly, population density with a greater likelihood of crowding into housing could result in greater viral transmission, and the second was that a higher prevalence of underlying chronic medical conditions could account for increased risk of hospitalizations and death [¹¹]. Moreover, an important source of transmission that initially received less attention was the higher proportion of racialized minorities engaged in lower paying “essential services” and critical infrastructure positions in exposed industries. These positions included health care support and such public facing front line positions as in food preparation and serving, grocery stores, building and ground cleaning, and transportation and material moving [¹²]. Distribution and uptake of personal protective equipment came late to these settings. Due to economic consequences of social distancing and local public impatience with adherence to behavioral public health interventions, essential workers could become exposed to infected persons through close contact. These interactions were sometimes exacerbated by violence from the public that resented admonitions to comply with mask orders.A major advance in the control of the COVID-19 pandemic has been the development and rollout of highly effective vaccines [^13–15]. Despite the sustained excess of cases, hospitalizations and deaths among Black, Hispanic, and Native American/Indigenous persons, rates of COVID-19 vaccine uptake have lagged behind that of Whites [¹⁶]. While uptake increased among all groups in March and April 2021, vaccine uptake continued to be lower among Black and Hispanic persons compared to Whites and Asians. This report also showed that the disparity increased over time. While Black and Hispanic persons have been more likely to be counted as cases, hospitalized, deaths, and rates of vaccine uptake remained the lowest.The purpose of this review is to examine the literature on vaccine hesitancy, acceptance, and intention. Given the profound disparities of cases, hospitalizations, and deaths by these social, cultural, and civic groupings, these factors are our primary focus. The first step was to summarize disparities in vaccine acceptance and uptake and then to identify key factors that shape those differences. While the issues of vaccine hesitancy and uptake are not new to the recent release of COVID-19 vaccine, the circumstances of this rapidly unfolding widespread public health crisis are different from previous bioevents. Lessons learned can provide insights into planning for future bio-events.     

From COVID-19 vaccine candidates to compulsory vaccination: The attitudes of Italian citizens in the key 7-month of vaccination campaign

IntroductionThe aim of the study is to understand the evolution of COVID-19 vaccine acceptance over the key 7-month vaccine campaign in Italy, a period in which the country moved from candidate vaccines to products administered to the public. The research focus points to evaluate COVID-19 vaccine attitudes in adults and their children, propension towards compulsory vaccination, past and present adherence to anti-flu and anti-pneumococcal vaccines, and the reasons for trust/mistrust of vaccines.MethodsItalian residents aged 16->65 years were invited to complete an online survey from September 2020 to April 2021. The survey contained 13 questions: 3 on demographic data; 8 on vaccine attitudes; and 2 open-ended questions about the reasons of vaccine confidence/refusal. A preliminary word frequency analysis has been conducted, as well as a statistical bivariate analysis.ResultsOf 21.537 participants, the confidence of those in favor of the COVID-19 vaccine increases of 50 % and the number of people who wanted more information decreases by two-third. Willingness to vaccinate their children against COVID-19 also increased from 51 % to 66.5 %. Only one-third of the strong vaccine-hesitant participants, i.e. 10 %, remained hostile. Compulsory vaccination showed a large and increasing favor by participants up to 78 %, in a way similar to their propensity for children’s mandatory vaccination (70.6 %). Respondents’ past and present adherence to anti-flu and anti-pneumococcal vaccines does not predict their intentions to vaccinate against COVID-19. Finally, a semantic analysis of the reasons of acceptance/refusal of COVID-19 vaccination suggests a complex decision-making process revealed by the participants’ use of common words in pro-and-cons arguments.ConclusionThe heterogeneity in the COVID-19 vaccine hesitancy, determinants and opinions detected at different ages, genders and pandemic phases suggests that health authorities should avoid one-size-fits-all vaccination campaigns. The results emphasize the long-term importance of reinforcing vaccine information, communication and education needs.     

Association of COVID-19 mortality with COVID-19 vaccination rates in Rhineland-Palatinate (Germany) from calendar week 1 to 20 in the year 2021: a registry-based analysis

Vaccination is among the measures implemented by authorities to control the spread of the COVID-19 pandemic. However, real-world evidence of population-level effects of vaccination campaigns against COVID-19 are required to confirm that positive results from clinical trials translate into positive public health outcomes. Since the age group 80?+?years is most at risk for severe COVID-19 disease progression, this group was prioritized during vaccine rollout in Germany. Based on comprehensive vaccination data from the German federal state of Rhineland-Palatinate for calendar week 1–20 in the year 2021, we calculated sex- and age-specific vaccination coverage. Furthermore, we calculated the proportion of weekly COVID-19 fatalities and reported SARS-CoV-2 infections formed by each age group. Vaccination coverage in the age group 80?+?years increased to a level of 80% (men) and 75% (women). Increasing vaccination coverage coincided with a reduction in the age group’s proportion of COVID-19 fatalities. In multivariable logistic regression, vaccination coverage was associated both with a reduction in an age-group’s proportion of COVID-19 fatalities [odds ratio (OR) per 5 percentage points?=?0.89, 95% confidence interval (CI)?=?0.82–0.96, p?=?0.0013] and of reported SARS-CoV-2 infections (OR per 5 percentage points?=?0.82, 95% CI 0.76–0.88, p?<?0.0001). The results are consistent with a protective effect afforded by the vaccination campaign against severe COVID-19 disease in the oldest age group.

     

Influenza vaccination uptake among Canadian adults before and during the COVID-19 pandemic: An analysis of the Canadian Longitudinal study on Aging (CLSA)

IntroductionUnderstanding how influenza vaccine uptake changed during the 2020/2021 influenza season compared to previous pre-pandemic seasons is a key priority, as is identifying the relationship between prior influenza vaccination and COVID-19 vaccine willingness.MethodsWe analyzed data from a large, nationally representative cohort of Canadian residents aged 50 and older to assess influenza vaccination status three times between 2015 and 2020. We investigated: 1) changes in self-reported influenza vaccine uptake, 2) predictors of influenza vaccine uptake in 2020/2021, and 3) the association between influenza vaccination history and self-reported COVID-19 vaccine willingness using logistic regression models.ResultsAmong 23,385 participants analyzed for aims 1–2, influenza vaccination increased over time: 14,114 (60.4%) in 2015–2018, 15,692 (67.1%) in 2019/2020, and 19,186 (82.0%; combining those already vaccinated and those planning to get a vaccine) in 2020/2021. After controlling for socio-demographics, history of influenza vaccination was most strongly associated with influenza vaccination in 2020/2021 (adjusted odds ratio [aOR] 147.9 [95% CI: 120.9–180.9]); this association remained after accounting for multiple health and pandemic-related factors (aOR 140.3 [95% CI: 114.5–171.8]). To a lesser degree, those more concerned about COVID-19 were also more likely to report influenza vaccination in fall 2020, whereas those reporting a very negative impact of the pandemic were less likely to get vaccinated. Among 23,819 participants with information on COVID-19 vaccine willingness during the last quarter of 2020 (aim 3), prior influenza vaccination was most strongly associated with willingness to get a COVID-19 vaccine (aOR 15.1 [95% CI: 13.5–16.8] for those who had received influenza vaccine at all previous timepoints versus none).ConclusionsOur analysis highlights the importance of previous vaccination in driving vaccination uptake and willingness. Efforts to increase vaccination coverage for influenza and COVID-19 should target individuals who do not routinely engage with immunization services regardless of demographic factors.     

Sociodemographic and psychological correlates of COVID-19 vaccine hesitancy and resistance in the young adult population in Italy

BackgroundPrevious research has shown that young adults are more hesitant/resistant to COVID-19 vaccine uptake than older age groups, although the factors underlying this tendency are still under debate. The current study aimed to identify the sociodemographic and psychological correlates of vaccine hesitancy and resistance among young adults (18–40 years) during the nationwide COVID-19 vaccination campaign in Italy, the first country after China being hit by the pandemic and which suffered a large number of fatalities.MethodsThis is a cross-sectional, web-based study conducted in Italy using an ISO-certified international survey company (respondi.com). Data were collected on 1200 participants in June 2021.ResultsVaccine hesitancy/resistance was found for 25% of the sample. In multinomial logistic regression (N = 1159), being aged 30–40 years, residing in northern Italy, having lower educational and income level, being unemployed, and not knowing any friends/relatives diagnosed with COVID-19 were associated with higher odds of hesitancy or resistance. In multivariate analysis of variance (N = 1177), both vaccine hesitant and resistant young adults perceived significantly less social support from friends and family than vaccine accepting ones. Resistant individuals reported significantly higher levels of conspiracy theories and negative attitudes toward vaccines than their accepting and hesitant counterparts. Moreover, resistant individuals reported significantly lower levels of attachment to country and perceptions of a just government compared to accepting ones, with hesitant young adults scoring in between.ConclusionsOur findings support the idea that young adults with a hesitant (vs. resistant) attitude show a more nuanced and less extreme psychological profile. Public health messaging should capitalize on social media to provide accessible, transparent, and age-appropriate information concerning COVID-19 vaccine safety. Moreover, policy efforts improving the availability of social support systems are warranted to strengthen connectedness and foster trust in institutions amongst this particular segment of the population.