Taking a machine learning approach to optimize prediction of vaccine hesitancy in high income countries.

Understanding factors driving vaccine hesitancy is crucial to vaccination success. We surveyed adults (N = 2510) from February to March 2021 across five sites (Australia = 502, Germany = 516, Hong Kong = 445, UK = 512, USA = 535) using a cross-sectional design and stratified quota sampling for age, sex, and education. We assessed willingness to take a vaccine and a comprehensive set of putative predictors. Predictive power was analysed with a machine learning algorithm. Only 57.4% of the participants indicated that they would definitely or probably get vaccinated. A parsimonious machine learning model could identify vaccine hesitancy with high accuracy (i.e. 82% sensitivity and 79-82% specificity) using 12 variables only. The most relevant predictors were vaccination conspiracy beliefs, various paranoid concerns related to the pandemic, a general conspiracy mentality, COVID anxiety, high perceived risk of infection, low perceived social rank, lower age, lower income, and higher population density. Campaigns seeking to increase vaccine uptake need to take mistrust as the main driver of vaccine hesitancy into account.

COVID-19 vaccination, time for a second breath?

One year into the Covid-19 vaccination campaign, C. Gerke, B. Pulverer and P. Sansonetti discuss its results and redefine its objectives.

Learning from the COVID-19 pandemic to strengthen routine immunization systems.

Kate Causey and Jonathan F Mosser discuss what can be learnt from the observed impacts of the COVID-19 pandemic on routine immunisation systems.

Are vaccine shortages a relevant public health issue in Europe? Results from a survey conducted in the framework of the EU Joint Action on Vaccination.

National immunisation programmes require an adequate supply of vaccines to function properly but many countries, globally and in Europe, have reported vaccine shortages. A comprehensive view of vaccine shortages and stockouts in the EU/EEA is missing in the published literature. This study was conducted in the framework of the European Joint Action on Vaccination (EU-JAV). Twenty-eight countries, including 20 EU-JAV consortium member states and an additional 8 EU/EEA countries, were invited to participate in a survey aimed at collecting information on vaccine shortages and stock-outs experienced from 2016 to 2019, their main causes, actions taken, and other aspects of vaccine supply. Twenty-one countries completed the survey (response rate 75%), of which 19 reported at least one shortage/stock-out event. Overall, 115 events were reported, 28 of which led to a change in the national immunisation programme. The most frequently involved vaccines were DT- and dT-containing combination vaccines, hepatitis B, hepatitis A, and BCG vaccines. The median duration of shortages/stock-outs was five months (range <1 month-39 months). Interruption in supply and global shortage were the most frequently indicated causes. Only about half of countries reported having an immunization supply chain improvement plan. Similarly, only about half of countries had recommendations or procedures in place to address shortages/stockouts. The survey also identified the occurrence of shortages/stockouts of other biological products (e.g. diphtheria antitoxin in 12 countries). Public health strategies to assure a stable and adequate vaccine supply for immunization programmes require coordinated actions from all stakeholders, harmonized definitions, strengthening of reporting and monitoring systems, the presence of an immunization supply chain improvement plan in all countries, and procedures or recommendations in place regarding the use of alternative vaccines or vaccination schedules in case of shortages/stockouts.

Strategies for COVID-19 vaccination under a shortage scenario: a geo-stochastic modelling approach.

In a world being hit by waves of COVID-19, vaccination is a light on the horizon. However, the roll-out of vaccination strategies and their influence on the pandemic are still open questions. In order to compare the effect of various strategies proposed by the World Health Organization and other authorities, a previously developed SEIRS stochastic model of geographical spreading of the virus is extended by adding a compartment for vaccinated people. The parameters of the model were fitted to describe the pandemic evolution in Argentina, Mexico and Spain to analyze the effect of the proposed vaccination strategies. The mobility parameters allow to simulate different social behaviors (e.g. lock-down interventions). Schemes in which vaccines are applied homogeneously in all the country, or limited to the most densely-populated areas, are simulated and compared. The second strategy is found to be more effective. Moreover, under the current global shortage of vaccines, it should be remarked that immunization is enhanced when mobility is reduced. Additionally, repetition of vaccination campaigns should be timed considering the immunity lapse of the vaccinated (and recovered) people. Finally, the model is extended to include the effect of isolation of detected positive cases, shown to be important to reduce infections.

Effect of Pfizer/BioNTech and Oxford/AstraZeneca vaccines against COVID-19 morbidity and mortality in real-world settings at countrywide vaccination campaign in Saudi Arabia.

OBJECTIVE: Vaccinations are highly essential to control infectious diseases and epidemics. Presently, the entire world faces a challenging crisis of "Severe Acute Respiratory Diseases Coronavirus 2 (SARS-CoV-2), also known as the COVID-19 pandemic". The impact of vaccines at national levels to reduce the SARS-CoV-2 cases and deaths are unclear, and people have concerns about the effectiveness of vaccines in real-world settings. This study's objective was to examine the effect of the "Pfizer/BioNTech and Oxford/AstraZeneca" vaccines to prevent SARS-CoV-2 cases and deaths in Saudi Arabia. MATERIALS AND METHODS: In this retrospective cohort study, we collected data on SARS-CoV-2 cases and deaths from the date of the first case of SARS-CoV-2 in Saudi Arabia March 2, 2020, to the date of launching the vaccination campaign on December 14, 2020; and from December 15, 2020, to September 8, 2021. We recorded the World Health Organization data and Ministry of Health of Saudi Arabia to evaluate the impact of the "Pfizer/BioNTech, (BNT162b2 mRNA) and Oxford/AstraZeneca (AZD1222)" vaccine against SARS-CoV-2 cases and deaths before and after the vaccination campaign in Saudi Arabia. RESULTS: Saudi Arabia launched the "Pfizer/BioNTech and Oxford/AstraZeneca" vaccination campaign against SARS-CoV-2 on December 14, 2020. In Saudi Arabia, before the vaccination campaign from March 2, 2020, to December 14, 2020, the mean daily SARS-CoV-2 cases were 1235.60, daily deaths were 22.70, that significantly reduced (p=0.0001) compared to the period after the vaccination campaign from December 15, 2020, to September 8, 2021, in which the daily cases fell to 692.08, and daily deaths fell to 9.48 (p=0.0001). CONCLUSIONS: In Saudi Arabia, Pfizer/BioNTech and Oxford/AstraZeneca vaccinations significantly reduced the number of SARS-CoV-2 cases and deaths after the vaccination compared to the period before the vaccination campaign at country levels. The study findings demonstrate that vaccination and adherence to nonpharmaceutical intervention can better control the COVID-19 pandemic.

Household visitation during the COVID-19 pandemic.

The COVID-19 pandemic has posed novel risks related to the indoor mixing of individuals from different households and challenged policymakers to adequately regulate this behaviour. While in many cases household visits are necessary for the purpose of social care, they have been linked to broadening community transmission of the virus. In this study we propose a novel, privacy-preserving framework for the measurement of household visitation at national and regional scales, making use of passively collected mobility data. We implement this approach in England from January 2020 to May 2021. The measures expose significant spatial and temporal variation in household visitation patterns, impacted by both national and regional lockdown policies, and the rollout of the vaccination programme. The findings point to complex social processes unfolding differently over space and time, likely informed by variations in policy adherence, vaccine relaxation, and regional interventions.

COVID-19 vaccination for people with severe mental illness: why, what, and how?

Psychiatric disorders, and especially severe mental illness, are associated with an increased risk of severe acute respiratory syndrome coronavirus 2 infection and COVID-19-related morbidity and mortality. People with severe mental illness should therefore be prioritised in vaccine allocation strategies. Here, we discuss the risk for worse COVID-19 outcomes in this vulnerable group, the effect of severe mental illness and psychotropic medications on vaccination response, the attitudes of people with severe mental illness towards vaccination, and, the potential barriers to, and possible solutions for, an efficient vaccination programme in this population.

Saudi experts' recommendation for RSV prophylaxis in the era of COVID-19: Consensus from the Saudi Pediatric Pulmonology Association.

Respiratory syncytial virus (RSV) is the most common cause of bronchiolitis and viral pneumonia in pediatrics worldwide. In the Kingdom of Saudi Arabia (KSA), the prevalence of RSV is 23.5% in pediatric patients with acute lower respiratory tract illness. Coronavirus disease (COVID-19) poses critical public health and socioeconomic challenges in KSA. The Saudi Pediatric Pulmonology Association (SPPA), a subsidiary of the Saudi Thoracic Society (STS), developed a task force to determine the potential challenges and barriers to the RSV immunoprophylaxis program during the era of COVID-19 and to compose a practical, nationwide, and multidisciplinary approach to address these challenges. Some of the recommendations to manage these challenges include increasing the number of RSV immunoprophylaxis clinics, drive-thru visits, home-care services, and swift referrals to the RSV immunoprophylaxis program specialists. Additional training is required for healthcare personnel to add RSV immunoprophylaxis to the regular immunization schedule.

Evaluation of a COVID-19 Vaccine Campaign and SARS-CoV-2 Infection and Mortality Among Adults Aged 60 Years And Older in a Middle-Income Country.

Importance: Although there are reports of COVID-19 vaccine implementation in real-world populations, these come from high-income countries or from experience with messenger RNA technology vaccines. Data on outcomes of vaccine deployment in low- or middle-income countries are lacking. Objective: To assess whether the pragmatic application of the 3 COVID-19 vaccines available in Argentina, 2 of which have no reports of evaluation in real-world settings to date, were associated with a reduction in morbidity, all-cause mortality, and mortality due to COVID-19. Design, Setting, and Participants: This cohort study used individual and ecological data to explore outcomes following vaccination with rAd26-rAd5, ChAdOx1, and BBIBP-CorV. To correct for differences in exposure times, results are shown using incidence density per 100 000 person-days from the start of the vaccination campaign (December 29, 2020) to the occurrence of an event or the end of follow-up (May 15, 2021). Participants included 663 602 people aged at least 60 years residing in the city of Buenos Aires, Argentina. Statistical analysis was performed from June 1 to June 15, 2021. Main Outcomes and Measures: Diagnosis of COVID-19 confirmed by reverse transcription-polymerase chain reaction, death from all causes, and death within 30 days of a diagnosis of COVID-19. Poisson regression models were fitted to estimate associations with all 3 outcomes. Results: Among 663 602 residents of the city of Buenos Aires included in the study, 540 792 (81.4%) were vaccinated with at least 1 dose, with 457 066 receiving 1 dose (mean [SD] age, 74.5 (8.9) years; 61.5% were female [n = 281 284]; 68.0% [n = 310 987] received the rAd26-rAd5 vaccine; 29.5% [n = 135 036] received ChAdOx1; 2.4% [n = 11 043] received BBIBP-CorV) and 83 726 receiving 2 doses (mean [SD] age, 73.4 [6.8] years; 63.5% were female [n = 53 204]). The incidence density of confirmed COVID-19 was 36.25 cases/100 000 person-days (95% CI, 35.80-36.70 cases/100 000 person-days) among those who did not receive a vaccine, 19.13 cases/100 000 person-days (95% CI, 18.63-19.62 cases/100 000 person-days) among those who received 1 dose, and 4.33 cases/100 000 person-days (95% CI, 3.85-4.81 cases/100 000 person-days) among those who received 2 doses. All-cause mortality was 11.74 cases/100 000 person-days (95% CI, 11.51-11.96 cases/100 000 person-days), 4.01 cases/100 000 person-days (95% CI, 3.78-4.24 cases/100 000 person-days) and 0.40 cases/100 000 person-days (95% CI, 0.26-0.55 cases/100 000 person-days). COVID-19-related-death rate was 2.31 cases/100 000 person-days (95% CI, 2.19-2.42 cases/100 000 person-days), 0.59 cases/100 000 person-days (95% CI, 0.50-0.67 cases/100 000 person-days), and 0.04 cases/100 000 person-days (95% CI, 0.0-0.09 cases/100 000 person-days) among the same groups. A 2-dose vaccination schedule was associated with an 88.1% (95% CI, 86.8%-89.2%) reduction in documented infection, 96.6% (95% CI, 95.3%-97.5%) reduction in all-cause death, and 98.3% (95% CI, 95.3%-99.4%) reduction in COVID-19-related death. A single dose was associated with a 47.2% (95% CI, 44.2%-50.1%) reduction in documented infection, 65.8% (95% CI, 61.7%-69.5%) reduction in all-cause death, and 74.5% (95% CI, 66%-80.8%) reduction in COVID-19-related death. Conclusions and Relevance: This study found that within the first 5 months after the start of the vaccination campaign, vaccination was associated with a significant reduction in COVID-19 infection as well as a reduction in mortality.

Translating Implementation Experiences and Lessons Learned From Polio Eradication Into a Global Health Course: Insights From an International Consortium.

Lessons learned from one global health program can inform responses to challenges faced by other programs. One way to disseminate these lessons is through courses. However, such courses are often delivered by and taught to people based in high-income countries and thus may not present a truly global perspective. The Synthesis and Translation of Research and Innovations from Polio Eradication (STRIPE) is a consortium of 8 institutions in Afghanistan, Bangladesh, the Democratic Republic of the Congo, Ethiopia, India, Indonesia, Nigeria, and the United States that seeks to carry out such a transfer of the lessons learned in polio eradication. This short report describes the collaborative process of developing content and curriculum for an international course, the learnings that emerged, the barriers we faced, and recommendations for future similar efforts. Various parts of our course were developed by teams of researchers from countries across South Asia and sub-Saharan Africa. We held a series of regional in-person team meetings hosted in different countries to improve rapport and provide a chance to work together in person. The course content reflects the diversity of team members' knowledge in a variety of contexts. Challenges to this effort included team coordination (e.g., scheduling across time zones); hierarchies across and between countries; and the coronavirus disease (COVID-19) pandemic. We recommend planning for these hierarchies ahead of time and ensuring significant in-person meeting time to make the most of international collaboration.

Real-time geospatial analysis identifies gaps in COVID-19 vaccination in a minority population.

COVID-19 vaccination is being rapidly rolled out in the US and many other countries, and it is crucial to provide fast and accurate assessment of vaccination coverage and vaccination gaps to make strategic adjustments promoting vaccine coverage. We reported the effective use of real-time geospatial analysis to identify barriers and gaps in COVID-19 vaccination in a minority population living in South Texas on the US-Mexico Border, to inform vaccination campaign strategies. We developed 4 rank-based approaches to evaluate the vaccination gap at the census tract level, which considered both population vulnerability and vaccination priority and eligibility. We identified areas with the highest vaccination gaps using different assessment approaches. Real-time geospatial analysis to identify vaccination gaps is critical to rapidly increase vaccination uptake, and to reach herd immunity in the vulnerable and the vaccine hesitant groups. Our results assisted the City of Brownsville Public Health Department in adjusting real-time targeting of vaccination, gathering coverage assessment, and deploying services to areas identified as high vaccination gap. The analyses and responses can be adopted in other locations.

SARS-CoV-2 vaccination efficacy on hospitalisation and variants.

We report data regarding three countries with similar healthcare systems which had three different vaccinal strategies between 1st of January and 10th of April 2021: rapid full vaccination (Israel), rapid first-dose vaccination (United Kingdom) and a delayed vaccination strategy (France).

COVID-19 Vaccination Efforts: Is Afghanistan Prepared?

A country's preparedness for a prompt and successful implementation of vaccination programs plays a pivotal role in disease control and prevention. As it stands now, Afghanistan seems to be ill-prepared to embrace a successful implementation of the COVID-19 vaccination program because of a spate of challenges. These include, but are not limited to, the insufficient number of vaccinators, a dearth of fully integrated functioning cold chain, challenging geographical barriers, cultural issues, insecurity, and protracted conflict. The COVID-19 infodemic along with vaccine mistrust in the country will lead to a pervasive public vaccine hesitancy in Afghanistan, which will present serious obstacles to the COVID-19 immunization efforts. The politicization of the Ministry of Public Health (MoPH) and the complaints of embezzlement and misuse of the pandemic aid have already eroded public trust during the pandemic. To ensure a large-scale and equitable distribution of COVID-19 vaccines, the cold chain infrastructure should be strengthened, and the immunization personnel trained. Antivaccination propaganda and misinformation should be tackled with effective communication approaches and effective community engagement, which consider culturally relevant messages appropriate to the culture and people. The allegations of corruption should be addressed to revive public trust in public health interventions, including COVID-19 vaccination.

Behavioural nudges increase COVID-19 vaccinations.

Enhancing vaccine uptake is a critical public health challenge1. Overcoming vaccine hesitancy2,3 and failure to follow through on vaccination intentions3 requires effective communication strategies3,4. Here we present two sequential randomized controlled trials to test the effect of behavioural interventions on the uptake of COVID-19 vaccines. We designed text-based reminders that make vaccination salient and easy, and delivered them to participants drawn from a healthcare system one day (first randomized controlled trial) (n = 93,354 participants; clinicaltrials number NCT04800965) and eight days (second randomized controlled trial) (n = 67,092 individuals; clinicaltrials number NCT04801524) after they received a notification of vaccine eligibility. The first reminder boosted appointment and vaccination rates within the healthcare system by 6.07 (84%) and 3.57 (26%) percentage points, respectively; the second reminder increased those outcomes by 1.65 and 1.06 percentage points, respectively. The first reminder had a greater effect when it was designed to make participants feel ownership of the vaccine dose. However, we found no evidence that combining the first reminder with a video-based information intervention designed to address vaccine hesitancy heightened its effect. We performed online studies (n = 3,181 participants) to examine vaccination intentions, which revealed patterns that diverged from those of the first randomized controlled trial; this underscores the importance of pilot-testing interventions in the field. Our findings inform the design of behavioural nudges for promoting health decisions5, and highlight the value of making vaccination easy and inducing feelings of ownership over vaccines.