Strategy to identify priority groups for COVID-19 vaccination: A population based cohort study

BackgroundEvidence from COVID-19 outbreak shows that individuals with specific chronic diseases are at higher risk of severe prognosis after infection. Public health authorities are developing vaccination programmes with priorities that minimize the risk of mortality and severe events in individuals and communities. We propose an evidence-based strategy that targets the frailest subjects whose timely vaccination is likely to minimize future deaths and preserve the resilience of the health service by preventing infections.MethodsThe cohort includes 146,087 cases with COVID-19 diagnosed in 2020 in Milan (3.49 million inhabitants). Individual level data on 42 chronic diseases and vital status updated as of January 21, 2021, were available in administrative data. Analyses were performed in three sub-cohorts of age (16–64, 65–79 and 80+ years) and comorbidities affecting mortality were selected by means of LASSO cross-validated conditional logistic regression. Simplified models based on previous results identified high-risk categories worth targeting with highest priority. Results adjusted by age and gender, were reported in terms of odds ratios and 95%CI.ResultsThe final models include as predictors of mortality (7,667 deaths, 5.2%) 10, 12, and 5 chronic diseases, respectively. The older age categories shared, as risk factors, chronic renal failure, chronic heart failure, cerebrovascular disease, Parkinson disease and psychiatric diseases. In the younger age category, predictors included neoplasm, organ transplantation and psychiatric conditions. Results were consistent with those obtained on mortality at 60 days from diagnosis (6,968 deaths).ConclusionThis approach defines a two-level stratification for priorities in the vaccination that can easily be applied by health authorities, eventually adapted to local results in terms of number and types of comorbidities, and rapidly updated with current data. After the early phase of vaccination, data on effectiveness and safety will give the opportunity to revise prioritization and discuss the future approach in the remaining population.     

COVID-19 vaccination and menstrual cycle characteristics: A prospective cohort study

We prospectively examined the association between COVID-19 vaccination and menstrual cycle characteristics in an internet-based prospective cohort study. We included a sample of 1,137 participants who enrolled in Pregnancy Study Online (PRESTO), a preconception cohort study of couples trying to conceive, during January 2021-August 2022. Eligible participants were aged 21–45 years, United States or Canadian residents, and trying to conceive without fertility treatment. At baseline and every 8 weeks for up to 12 months, participants completed questionnaires on which they provided information on COVID-19 vaccination and menstrual cycle characteristics, including cycle regularity, cycle length, bleed length, heaviness of bleed, and menstrual pain. We fit generalized estimating equation (GEE) models with a log link function and Poisson distribution to estimate the adjusted risk ratio (RR) for irregular cycles associated with COVID-19 vaccination. We used linear regression with GEE to estimate adjusted mean differences in menstrual cycle length associated with COVID-19 vaccination. We adjusted for sociodemographic, lifestyle, medical and reproductive factors. Participants had 1.1 day longer menstrual cycles after receiving the first dose of COVID-19 vaccine (95 % CI: 0.4, 1.9) and 1.3 day longer cycles after receiving the second dose (95 % CI: 0.2, 2.5). Associations were attenuated at the second cycle post-vaccination. We did not observe strong associations between COVID-19 vaccination and cycle regularity, bleed length, heaviness of bleed, or menstrual pain. In conclusion, COVID-19 vaccination was associated with a ∼1 day temporary increase in menstrual cycle length, but was not appreciably associated with other menstrual cycle characteristics.     

Nepal measles outbreak response immunization during COVID-19: A risk-based intervention strategy

In 2020, National Immunization Programme (NIP) of Nepal implemented a measles outbreak response immunization (ORI) campaign, which was additional to an ongoing preventive measles-rubella SIA campaign. Both campaigns were implemented during ongoing COVID-19 transmission. By April, 220 measles cases and two deaths were confirmed from eight districts of Nepal. The NIP triangulated information from surveillance (measles and COVID-19), measles immunization performance and immunity profile, programme capacities and community engagement and applied a logical decision-making framework to the collated data to inform ‘Go/No-Go’ decisions for ORI interventions. This was reviewed by the National Immunization Advisory Committee (NIAC) for endorsement. Outbreak response with non-selective immunization (ORI), vitamin-A administration and case management were implemented in affected municipalities of four districts, while in the remaining districts outbreak response without ORI were undertaken. The structure and iterative application of this logical framework has been described. ORI was implemented without interrupting the ongoing measles-rubella vaccination campaign which had targeted children from 9 to 59 months of age. The age group for ORI was same as SIA in one sub-district area, while for the other three sub-district areas it was from 6 months to 15 years of age. More than 32,000 persons (97% coverage) were vaccinated in ORI response. Overall measles incidence decreased by 98% after ORI. The daily incidence rate of measles was 94 times higher (95% confidence interval: 36.11 – 347.62) before the ORI compared to two weeks after ORI until year end. Close attention to surveillance and other data to inform actions and seamless collaboration between NIP and core immunization partners (WHO, UNICEF), with guidance from NIAC were key elements in successful implementation. This was an example of feasible application of the global framework for implementation of a mass vaccination campaign during COVID-19 through application of a simple decision-making logical framework.     

Prenatal maternal COVID-19 vaccination and pregnancy outcomes

BackgroundPrenatal maternal physiological changes may cause severe COVID-19 among pregnant women. The Pfizer-BioNTech COVID-19 vaccine (BNT162b2 mRNA) has been shown to be highly effective and it is recommended for individuals aged ≥16 years, including pregnant women, although the vaccine has not been tested on the latter.ObjectiveTo study the association between prenatal Pfizer-BioNTech COVID-19 vaccination, pregnancy course and outcomes.Study designA retrospective cohort study was performed, including all women who delivered between January and June 2021 at Soroka University Medical Center, the largest birth center in Israel. Excluded were women diagnosed with COVID-19 in the past, multiple gestations or unknown vaccination status. Pregnancy, delivery and newborn complications were compared between women who received 1 or 2-dose vaccines during pregnancy and unvaccinated women. Multivariable models were used to adjust for background characteristics.ResultsA total of 4,399 women participated in this study, 913 (20.8%) of which were vaccinated during pregnancy. All vaccinations occurred during second or third trimesters. As compared to the unvaccinated women, vaccinated women were older, more likely to conceive following fertility treatments, to have sufficient prenatal care, and of higher socioeconomic position. In both crude and multivariable analyses, no differences were found between the groups in pregnancy, delivery and newborn complications, including gestational age at delivery, incidence of small for gestational age and newborn respiratory complications.ConclusionsPrenatal maternal COVID-19 vaccine has no adverse effects on pregnancy course and outcomes. These findings may help pregnant women and health care providers to make informed decision regarding vaccination.     

全球新冠疫苗研发与接种策略进展

WHO于2023年5月5日宣布新型冠状病毒感染(corona virus disease 2019,COVID-19)疫情不再构成国际关注的突发公共卫生事件。全球疫情相对稳定,但是各国仍不能放松对COVID-19的警惕。接种新冠疫苗仍是有效的预防手段。本文主要围绕当前全球新冠疫苗研发进展、不同国家疫苗接种策略调整情况等进行对比分析,并结合WHO推荐对新冠疫苗接种策略的最新指导意见,分析探讨全球新冠疫苗研发及各国疫苗接种策略对我国的启示,提出适合我国国情的针对性疫苗接种建议。     

A qualitative study of parental views of HPV vaccination in Ireland

BackgroundDespite significant evidence supporting the Human Papillomavirus (HPV) vaccine in the prevention of cervical cancer, uptake of this vaccine is below target in many countries. HPV uptake in Ireland has declined from 87% in 2014–15 to 51% in 2016–17 and currently remains suboptimal at 64.1% in 2017–18.ObjectivesThis study aimed to explore parental views of the HPV vaccine; elucidate specific concerns relating to this vaccine and to identify relevant influences on the decision to vaccinate against HPV to inform strategies to optimise uptake.MethodsAn in-depth qualitative study, using semi-structured interviews was conducted among parents of 11–13-year-old girls (n = 18) who had not yet been offered the HPV vaccine. Convenience sampling was used. Interviews, conducted in the Republic of Ireland over six-months in 2018, were audio-recorded, transcribed, and analysed by thematic analysis.ResultsEighteen interviews were conducted (14 female and 4 male participants). Parents favoured HPV vaccination to protect their daughters and prevent disease. Barriers to vaccination included; the fear of long-term side effects, lack of knowledge and the risk versus benefit ratio. General practitioners (GPs) were identified as having a strong influence over parental vaccination decisions, as did media reports and the recent cervical screening programme controversy in Ireland.ConclusionThis study suggests that significant parental concerns remain to the HPV vaccine. More comprehensive information on the research surrounding this vaccine’s safety profile is required. GP’s may play a pivotal role in HPV vaccination going forward.     

COVID-19 vaccination in pregnant women in Sweden and Norway

Vaccines against SARS-CoV-2 are highly effective in preventing severe disease and mortality. Although pregnant women are at increased risk of severe COVID-19, vaccination uptake among pregnant women varies. We used the Swedish and Norwegian population-based health registries to identify pregnant women and to investigate background characteristics associated with not being vaccinated. In this study of 164 560 women giving birth between May 2021 and May 2022, 78% in Sweden and 87% in Norway have been vaccinated with at least one dose at delivery. Not being vaccinated while being pregnant was associated with age below 30 years, low education and income level, birth region other than Scandinavia, smoking during pregnancy, not living with a partner, and gestational diabetes. These results can assist health authorities develop targeted vaccination information to diminish vaccination inequality and prevent severe disease in vulnerable groups.     

Safety and immunogenicity of heterologous ChAdOx1-nCoV19 and BNT162b2 vaccination: A meta-analysis of the heterologous COVID-19 vaccination outcomes

IntroductionHere, we systematically assessed the safety and immunogenicity of the heterologous ChAd/BNT vaccination regimens.Materials and methodsWe evaluated the immunogenicity by the geometric mean titers ratio (GMTR) of the neutralizing antibody and anti-spike IgG. The safety of heterologous ChAd/BNT vaccination was evaluated using the pooled risk ratios (RRs) calculated by the random-effects model about the adverse events. Our study was registered with PROSPERO, CRD42021265165.ResultsEleven studies were included in the analyses. Compared to the homologous ChAd/ChAd vaccination, the heterologous ChAd/BNT vaccination showed significantly higher immunogenicity in terms of the neutralizing antibody and GMTR of anti-spike IgG, but at the same time displayed higher incidence of total adverse reactions, especially for the local adverse reactions. Moreover, heterologous ChAd/BNT vaccination showed similar immunogenicity to the homologous BNT/BNT vaccination (GMTR of neutralizing antibody and anti-spike IgG) and similar safety.DiscussionHeterologous ChAd/BNT vaccination showed robust immunogenicity and tolerable safety.     

The effect of SARS-CoV-2 vaccination on post-acute sequelae of COVID-19 (PASC): A prospective cohort study

BackgroundSymptoms of post-acute sequelae of COVID-19 (PASC) may improve following SARS-CoV-2 vaccination. However few prospective data that also explore the underlying biological mechanism are available. We assessed the effect of vaccination on symptomatology of participants with PASC, and compared antibody dynamics between those with and without PASC.MethodsRECoVERED is a prospective cohort study of adult patients with mild to critical COVID-19, enrolled from illness onset. Among participants with PASC, vaccinated participants were exact-matched 1:1 on age, sex, obesity status and time since illness onset to unvaccinated participants. Between matched pairs, we compared the monthly mean numbers of symptoms over a 3-month follow-up period, and, using exact logistic regression, the proportion of participants who fully recovered from PASC. Finally, we assessed the association between PACS status and rate of decay of spike- and RBD-binding IgG titers up to 9 months after illness onset using Bayesian hierarchical linear regression.FindingsOf 349 enrolled participants, 316 (90.5%) had ≥3 months of follow-up, of whom 186 (58.9%) developed PASC. Among 36 matched pairs with PASC, the mean number of symptoms reported each month during 3 months of follow-up were comparable between vaccinated and unvaccinated groups. Odds of full recovery from PASC also did not differ between matched pairs (OR 1.57 [95%CI 0.46–5.84]) within 3 months after the matched time-point. The median half-life of spike- and RBD-binding IgG levels were, in days (95%CrI), 233 (183–324) and 181 (147–230) among participants with PASC, and 170 (125–252) and 144 (113–196) among those without PASC, respectively.InterpretationOur study found no strong evidence to suggest that vaccination improves symptoms of PASC. This was corroborated by comparable spike- and RBD-binding IgG waning trajectories between those with and without PASC, refuting any immunological basis for a therapeutic effect of vaccination on PASC.     

Retention of general practitioners in rural Nepal: a qualitative study

Objectives:  To explore the key issues that influence GP retention in rural areas of Nepal.
Design:  A qualitative study using triangulation of data from one postal questionnaire, one hand-delivered questionnaire with semistructured interview and focus group discussions. Data from a small community survey from 13 rural districts also included.
Participants:  Sixty-two Nepali GPs, 25 doctors in General Practice training programs, 11 individuals involved in policy development and rural health care.
Results:  The key issues identified by this study as critical to the retention of Nepali GPs in rural areas were:
•  Career/promotion prospects
•  Status/recognition
•  Financial incentives
•  Working conditions
•  Education for children
•  Continuing medical education
•  Political stability and security
Conclusions:  The strongest theme was that of career development. This must be addressed by the Government of Nepal if there is to be any hope of improving retention of GPs in rural areas. GPs need to have a clear career ladder, with recognition of the value of service in rural areas. There is, however, no one single answer to the complex interacting factors that impact on GP retention in rural Nepal. A multifaceted, holistic response is necessary. From the level of community awareness, a career structure and financial remuneration to adequately set up hospitals, functional teams, family support, continuing professional development and a secure working environment – each area must be addressed for the whole to function.     

The social and socio-political embeddedness of COVID-19 vaccination decision-making: A five-country qualitative interview study from Europe

The uptake of COVID-19 vaccines has varied considerably across European countries. This study investigates people’s decision-making process regarding vaccination by analyzing qualitative interviews (n = 214) with residents from five European countries: Austria, Germany, Italy, Portugal, and Switzerland. We identify three factors that shape vaccination decision-making: individual experiences and pre-existing attitudes towards vaccination, social environment, and socio-political context. Based on this analysis, we present a typology of decision-making regarding COVID-19 vaccines, where some types present stable stances towards vaccines and others change over time. Trust in government and relevant stakeholders, broader social factors, and people’s direct social environment were particularly relevant to these dynamics. We conclude that vaccination campaigns should be considered long-term projects (also outside of pandemics) in need of regular adjustment, communication and fine-tuning to ensure public trust. This is particularly pertinent for booster vaccinations, such as COVID-19 or influenza.     

Early exploration of COVID-19 vaccination safety and effectiveness during pregnancy: interim descriptive data from a prospective observational study

ObjectiveDuring December 2020, a massive vaccination program was introduced in our country. The Pfizer-BioNTech, BNT162b2 vaccine was first offered exclusively to high-risk population, such as medical personnel (including pregnant women). In this study we compare short term outcomes in vaccinated vs. non-vaccinated pregnant women.MethodsIn this prospective observational cohort study, vaccinated and non-vaccinated pregnant women were recruited using an online Google forms questionnaire targeting medical groups on Facebook and WhatsApp. A second questionnaire was sent one month after the first one for interim analysis. Our primary outcome was composite complications in vaccinated and non-vaccinated groups, considered any of the following: vaginal bleeding, pregnancy loss, hypertension, gestational diabetes, and preterm birth. Secondary outcomes included: vaccine side effects, diagnosis of COVID-19 since the last questionnaire, prevalence of vaccinated participants, and reasons for refusal to be vaccinated.ResultsOverall, 432 women answered the first questionnaire, of which 326 responses were received to the second questionnaire. Vaccination rate increased from 25.5% to 62% within a month. Maternal age, gestational age at enrollment, nulliparity and number of children were similar in both groups. The rate of composite pregnancy complications was similar between vaccinated and non-vaccinated group (15.8% vs 20.1%, p = 0.37), respectively. The risk for COVID-19 infection was significantly lower in the vaccinated group (1.5% vs 6.5%, p = 0.024, Odds Ratio: 4.5, 95% confidence interval 1.19–17.6).ConclusionsmRNA vaccine during pregnancy does not seem to increase the rate of pregnancy complications and is effective in prevention of COVID-19 infection.     

Influenza vaccination in the time of COVID-19: A national U.S. survey of adults

IntroductionDecisions about influenza vaccination for fall-winter 2020 were made against the backdrop of the COVID-19 pandemic. During May 2020, the authors examined intended vaccination in the next 12 months in relationship to demographic variables, healthcare attitudes, and personal COVID-19 experiences for two samples of adults--those who did not receive influenza vaccine during the prior 12 months, and those who did.MethodsIn May 2020, a cross-sectional online survey was conducted with a national US sample. Participants reported prior influenza vaccination (yes/no during prior 12 months) and anticipated vaccination (yes/no during next 12 months). Covariates included demographic characteristics (e.g., gender, race-ethnicity, political ideology), general beliefs (e.g., benefits of vaccines, altruistic attitudes), and COVID-19 health beliefs and experiences (COVID-19 worry and severity, perception of COVID-19 as a community threat, knowing someone with COVID-19). For each group, hierarchical multivariable logistic regression was conducted with intent to vaccinate as the outcome.ResultsAmong participants (n = 3502), 47% did not receive influenza vaccine in the prior 12 months and 53% had; 25.5% of non-vaccinators and 91.9% of vaccinators intended future vaccination. For non-vaccinators, odds of intending vaccination was associated with race/ethnicity (Hispanics were more likely to intend than white-NH; AOR = 1.74; 95% CI = 1.23–2.4), greater perceived benefits of vaccination (AOR = 2.19; 95% CI = 1.88–2.54), and perception of COVID-19 as a community threat (AOR = 1.91; 95% CI = 1.49–2.45). For vaccinators, odds of intending vaccination was associated with age (AOR = 1.04; 95% CI = 1.03–1.05), race/ethnicity (Black-NH and Other-NH were less likely to intend than white-NH, AOR = 0.60; 95% CI = 0.36–0.999; and AOR = 0.45; 95% CI = 0.24–0.84, respectively), greater perceived benefits of vaccination (AOR = 1.88; 95% CI = 1.45–2.45) and greater perception of collective benefits of vaccines (AOR = 1.48; 95% CI = 1.15–1.90).ConclusionsThe COVID-19 pandemic may have served as a cue to action for influenza vaccination intention among some prior non-vaccinators whereas intention among prior vaccinators is more related to positive attitudes toward vaccination.     

Potential impact of COVID-19 pandemic on vaccination coverage in children: A case study of measles-containing vaccine administration in the United States (US)

BackgroundThe COVID-19 pandemic and stay-at-home orders have caused an unprecedented decrease in the administration of routinely recommended vaccines. However, the impact of this decrease on overall vaccination coverage in a specific birth cohort is not known.MethodsWe projected measles vaccination coverage for the cohort of children becoming one year old in 2020 in the United States, for different durations of stay-at-home orders, along with varying catch-up vaccination efforts.ResultsA 15% sustained catch-up rate outside stay-at-home orders (compared to what would be expected via natality information) may be necessary to achieve projected vaccination coverage similar to previous years. Permanent decreases in vaccine administration could lead to projected vaccination coverage levels below 80%.ConclusionModeling measles vaccination coverage under a range of scenarios provides useful information about the potential magnitude and impact of under-immunization. Sustained catch-up efforts are needed to assure that measles vaccination coverage remains high.     

Barriers to COVID-19 vaccination of migrant populations: A qualitative interview study of immunisation providers in Victoria,Australia

IntroductionThis study aimed to understand barriers and enablers, future strategies, communication approaches and resources needed for COVID-19 vaccination among migrant communities in Melbourne, Australia.Material and methodsWe interviewed 24 immunisation providers who deliver immunisation services to migrant populations in Melbourne. We used the WHO Behavioural and Social Drivers framework (underlined) to organise barriers and enablers to COVID-19 vaccination.ResultsParticipants believed migrants had concerns about vaccine safety and efficacy and saw vaccines as minimally beneficial in the ‘low COVID-19′ environment of Australia (what people think and feel). Healthcare providers with established relationships within migrant communities played key roles in vaccine advocacy (social processes). Migrants’ vaccine motivation was mediated by health literacy, institutional trust and previous experiences with health services. Practical issues included perceived lack of information on vaccine booking process and accessibility challenges.ConclusionsStrategies to increase migrant vaccine coverage should utilise immunisation providers with community links and trusted local vaccine ambassadors to engage and address community vaccine concerns.     

Safety of simultaneous vaccination with COVID-19 vaccines in the Vaccine Safety Datalink

IntroductionSafety data on simultaneous vaccination (SV) with primary series monovalent COVID-19 vaccines and other vaccines are limited. We describe SV with primary series COVID-19 vaccines and assess 23 pre-specified health outcomes following SV among persons aged ≥5 years in the Vaccine Safety Datalink (VSD).MethodsWe utilized VSD’s COVID-19 vaccine surveillance data from December 11, 2020-May 21, 2022. Analyses assessed frequency of SV. Rate ratios (RRs) were estimated by Poisson regression when the number of outcomes was ≥5 across both doses, comparing outcome rates between COVID-19 vaccinees receiving SV and COVID-19 vaccinees receiving no SV in the 1–21 days following COVID-19 vaccine dose 1 and 1–42 days following dose 2 by SV type received (“All SV”, “Influenza SV”, “Non-influenza SV”).ResultsSV with COVID-19 vaccines was not common practice (dose 1: 0.7 % of 8,455,037 persons, dose 2: 0.3 % of 7,787,013 persons). The most frequent simultaneous vaccines were influenza, HPV, Tdap, and meningococcal. Outcomes following SV with COVID-19 vaccines were rare (total of 56 outcomes observed after dose 1 and dose 2). Overall rate of outcomes among COVID-19 vaccinees who received SV was not statistically significantly different than the rate among those who did not receive SV (6.5 vs. 6.8 per 10,000 persons). Statistically significant elevated RRs were observed for appendicitis (2.09; 95 % CI, 1.06–4.13) and convulsions/seizures (2.78; 95 % CI, 1.10–7.06) in the “All SV” group following dose 1, and for Bell’s palsy (2.82; 95 % CI, 1.14–6.97) in the “Influenza SV” group following dose 2.ConclusionCombined pre-specified health outcomes observed among persons who received SV with COVID-19 vaccine were rare and not statistically significantly different compared to persons who did not receive SV with COVID-19 vaccine. Statistically significant adjusted rate ratios were observed for some individual outcomes, but the number of outcomes was small and there was no adjustment for multiple testing.