A Four Years Longitudinal Study of Childhood Vaccination Trends and Supply Chain Resilience in Tanzania amid COVID-19 Pandemic (preprint)

Background The COVID-19 pandemic has significantly disrupted healthcare systems at all levels globally, notably affecting routine healthcare services such as childhood immunisations. This study delves into the impact of these disruptions on routine childhood vaccination programs in Tanzania. Methodology We conducted a longitudinal study over four years in five Tanzanian regions: Mwanza, Dar es Salaam, Mtwara, Arusha, and Dodoma. The study analysed trends in the usage of six key vaccines: Bacille Calmette-Guérin (BCG), Bivalent Oral Polio Vaccine (bOPV), Diphtheria Tetanus Pertussis, Hepatitis-B and Hib vaccine (DTP-HepB-Hib), measles-rubella (MR), Pneumococcal Conjugate Vaccine (PCV), and Rota vaccines. We evaluated annual and monthly vaccination trends using time series and regression analyses. Predictive modelling was performed using an Autoregressive Integrated Moving Average (ARIMA) model. Results The study recorded a total of 32,602,734 vaccination events across the regions from 2019 to 2022. Despite declining vaccination rates in 2020, there was a notable rebound in 2021, indicating the resilience of Tanzania's immunisation program. The analysis also highlighted regional differences in varying vaccination rates when standardised per 1000 population. Seasonal fluctuations were observed in the monthly vaccination rates, with BCG showing the most stable trend. Predictive modelling of BCG indicated stable and increasing vaccination coverage through 2023. Conclusion The findings underscore the robustness of Tanzania's childhood immunisation infrastructure in overcoming the challenges posed by the COVID-19 pandemic, marked by a strong recovery in vaccination rates post-2020. We provide valuable insights into the dynamics of vaccinations during a global health crisis and highlight the importance of sustained immunisation efforts in maintaining public health.

Impact of pregnancy on polyfunctional IgG and memory B cell responses to Tdap immunization.

BACKGROUND: Maternal pertussis immunization using Tdap vaccine is recommended in many countries to protect newborns from severe post-natal infection. Immunological changes during pregnancy may influence the response to vaccines. The quality of IgG and memory B cell responses to Tdap immunization in pregnant women has not yet been described. METHODS: The impact of pregnancy on the response to Tdap vaccination was assessed by comparing humoral immune responses in 42 pregnant and 39 non-pregnant women. The levels of serum pertussis antigens and tetanus toxoid-specific IgG, IgG subclasses, IgG Fc-mediated effector functions, as well as memory B cell frequencies were assessed before and at several time points after vaccination. RESULTS: Tdap immunization induced similar levels of pertussis and tetanus-specific IgG and IgG subclasses in pregnant and non-pregnant women. Pregnant women produced IgG promoting complement deposition, and neutrophils and macrophages phagocytosis at levels comparable to non-pregnant women. They were also able to expand pertussis and tetanus-specific memory B cells at similar frequencies as non-pregnant women, suggesting equivalent "boostability". Higher levels of vaccine-specific IgG, IgG subclasses, and IgG Fc-mediated effector functions were detected in cord blood as compared to maternal blood, indicating efficient transport across the placenta. CONCLUSIONS: This study demonstrates that pregnancy does not affect the quality of effector IgG and memory B cell responses to Tdap immunization and that polyfunctional IgG are efficiently transferred across the placenta. REGISTRY'S URL AND THE TRIAL'S REGISTRATION NUMBER: ClinicalTrials.Gov (NCT03519373).

Vaccination in pregnancy.

The evidence indicates that pregnancy is associated with increased severity of some infectious diseases. Given the high maternal morbidity associated with influenza in pregnancy and the high neonatal morbidity and mortality associated with pertussis, the traditionally two recommended vaccines during pregnancy were those against influenza and Tdap (tetanus toxoid, reduced diphtheria toxoid and acellular pertussis) vaccines. The recent COVID-19 pandemic introduced a third vaccine that after much debate is now recommended for all pregnant women. Other vaccines can be offered based for high-risk pregnant women, and only when the benefits of receiving them outweigh the risks. The soon expected vaccines against group B streptococcus infection and respiratory syncytial virus infection will be a breakthrough in reducing perinatal mortality. In this paper, the recommendations for administration of each vaccine during pregnancy are discussed.

Influenza and pertussis vaccine coverage in pregnancy in Australia, 2016-2021.

Vaccination in pregnancy is the best strategy to reduce complications from influenza or pertussis infection in infants who are too young to be protected directly from vaccination. Pregnant women are also at risk of influenza complications preventable through antenatal vaccination. Both vaccines are funded under the National Immunisation Program for pregnant women in Australia, but coverage is not routinely reported nationally. We reviewed all reported Australian maternal influenza and pertussis vaccine coverage data for the period 2016-2021, to identify gaps and information needs. Maternal influenza vaccine coverage was suboptimal at < 58% for 2016-2018, with higher coverage of 62-75% reported in two states (Victoria and Western Australia) for 2019-2021. Maternal pertussis vaccine coverage from 2016 was generally higher than for influenza at > 70%, with the highest jurisdictional coverage of 89% reported in Western Australia in 2020. Vaccination rates were often suboptimal among First Nations pregnant women and up to 20% lower than among non-First Nations Australian women; while data were limited, coverage was low among culturally and linguistically diverse women and among women of lower socio-economic status. Jurisdictional perinatal data collections were the best source of information on antenatal vaccine coverage but were only available for a minority of the population; a nationally consistent systematic approach is lacking. Timely and comprehensive data are needed to provide feedback to improve maternal vaccination coverage, particularly among groups with higher risk and/or low uptake, and as new vaccines are recommended, including COVID-19 vaccination.

Evaluation of BioFire Respiratory Panel 2 plus for Detection of Bordetella pertussis in Nasopharyngeal Swab Specimens from Children with Clinically Suspected Pertussis.

The objective of this study was to compare the performances of BioFire Respiratory Panel 2 (RP2) plus, quantitative real-time PCR (qPCR), and culture for the detection of Bordetella pertussis in nasopharyngeal swab (NPS) specimens. Consecutive NPS specimens were collected from patients with clinically suspected pertussis from 1 March 1 to 31 July 2018 in Shenzhen Children's Hospital. All the specimens were tested in parallel by RP2 plus, qPCR, and culture methods. A total of 464 children were enrolled in this study. The positive pertussis rates of culture, RP2 plus, and qPCR were 23.1%, 39.0%, and 38.4%, respectively. Compared to the combined reference standard, the sensitivity, specificity, positive predictive value, and negative predictive values were, respectively, 56.6% (95% confidence interval [CI], 49.2 to 63.7%), 100% (98.3 to 100%), 100% (95.7 to 100%), and 77.0% (72.2 to 81.2%) for culture, 89.9% (84.5 to 93.7%), 96.0% (92.8 to 97.9%), 93.9% (89.1 to 96.8%), and 93.3% (89.5 to 95.8%) for RP2 plus, and 86.8% (80.9 to 91.1%), 94.9% (91.4 to 97.1%), 92.1% (86.9 to 95.5%), and 91.3% (87.2 to 94.2%) for qPCR. The most prevalent codetected pathogen was human rhinovirus/enterovirus (n = 99, 52.4%), followed by parainfluenza virus (n =32, 16.9%) and respiratory syncytial virus (n = 29, 15.3%), in children with B. pertussis present, which was consistent with the top three pathogens previously found in children with B. pertussis absent. Turnaround times for RP2 plus, qPCR, and culture were 2 h, 8 h, and 120 h, respectively. RP2 plus quickly and accurately detected B. pertussis, providing valuable information for an early clinical diagnosis and optimal choice of therapy. IMPORTANCE In recent years, there have been some epidemic or local outbreaks of pertussis in countries with high vaccination rates. One of the crucial factors in controlling pertussis is early diagnosis, which is based on specific laboratory measurements, including culture, serological tests, and PCR assays. Compared to culture and serological tests, PCR is more suitable for clinical application, with a fast detection speed of several hours independent of the disease stage and individual vaccination status. BioFire Respiratory Panel 2 plus, a multiplex PCR assay for simultaneously detecting 22 respiratory pathogens, facilitates the quick detection of Bordetella pertussis and coinfecting respiratory pathogens. It also provides valuable information for an early clinical diagnosis and optimal choice of therapy for children with clinically suspected pertussis.

Acceptance of vaccination against pertussis, COVID-19 and influenza during pregnancy: a cross-sectional study.

BACKGROUND: This study aims to assess the uptake of maternal pertussis and COVID-19 vaccination and the intention towards accepting the maternal influenza vaccination. Insights into different socio-demographic factors related to maternal vaccination coverage might help to address vaccine acceptance and improve maternal vaccine uptake in the future. METHODS: We conducted a cross-sectional survey among pregnant women and recent mothers, up to 6 months post-partum. The primary outcome measures of this study were behaviour for maternal pertussis and COVID-19 vaccination, and maternal influenza vaccination intention. Associations between socio-demographic factors and maternal pertussis vaccination and maternal COVID-19 vaccination behaviour; and socio-demographic factors and maternal influenza vaccination intention were assessed using binary logistic regression analyses. RESULTS: In total 1361 respondents filled out the questionnaire. Almost all women (95%) were vaccinated against pertussis during pregnancy, while almost two-third were vaccinated against COVID-19 during pregnancy (58%) and almost one-third (28%) had a positive intention towards receiving the maternal influenza vaccination. Results show that young maternal age and low education level were associated with lower maternal vaccination acceptance. CONCLUSION: Vaccination campaigns focusing on the severity of diseases that are prevented, are needed to increase maternal vaccine acceptance in younger and low-educated pregnant women. We expect that differences in vaccination coverage between the three maternal vaccinations might partly be explained by existing recommendations, campaigns and whether the vaccination is part of the national immunisation program.

mSphere of Influence: Pertussis Vaccination and Antibodies in Mothers and Infants.

Susana Portillo works in the field of mother-infant immunity with an emphasis on vaccination and prevention of respiratory diseases. In this mSphere of Influence, she reflects here on how two pertussis vaccine articles made an impact on her research. She discusses how much more remains to be understood about the role of maternal antibodies in preventing or reducing infant illnesses, their capacity to engage other immune components to deliver an efficient antimicrobial response, and their influence on the infant's own response to vaccination. She emphasizes the need for safe and effective interventions that strengthen maternal and infant immunity before and after birth.

Assessing the relationship between operationally defined zero-dose communities and access to selected primary healthcare services for children and pregnant women in emergency settings.

In this study the authors examine the relationship between "zero-dose" communities and access to healthcare services. This was done by first ensuring the first dose of the Diphtheria Tetanus and Pertussis vaccine was a better measure of zero-dose communities than the measles-containing vaccine. Once ensured, it was used to examine the association with access to primary healthcare services for children and pregnant women in the Democratic Republic of Congo, Afghanistan, and Bangladesh. These services were divided into: a) unscheduled healthcare services such as birth assistance as well as seeking care and treatment for diarrheal diseases and cough/fever episodes and b) other scheduled health services such as antenatal care visits and vitamin A supplementation. Using recent Demographic Health Survey data (2014: Democratic Republic of Congo, 2015: Afghanistan, 2018: Bangladesh), data was analyzed via Chi Squared analysis or Fischer's Exact Test. If significant, a linear regression analysis was performed to examine if the association was linear. While the linear relationship observed between children who had received the first dose of the Diphtheria Tetanus and Pertussis vaccine (the reverse to zero-dose communities) and coverage of other vaccines was expected, the results of the regression analysis depicted an unexpected split in behavior. For scheduled and birth assistance health services, a linear relationship was generally observed. For unscheduled services associated with illness treatments, this was not the case. While it does not appear that the first dose of the Diphtheria Tetanus and Pertussis vaccine can be used to predict (at least in a linear manner) access to some primary (particularly illness treatment) healthcare services in emergency/ humanitarian settings, it can serve as an indirect measure of health services not associated with the treatment of childhood infections such as antenatal care, skilled birth assistance, and to a lesser degree even vitamin A supplementation.

Barriers and facilitators of vaccine hesitancy for COVID-19, influenza, and pertussis during pregnancy and in mothers of infants under two years: An umbrella review.

BACKGROUND: Vaccination during pregnancy has been repeatedly demonstrated to be safe and effective in protecting against infection and associated harms for the mother, developing baby, and subsequent infant. However, maternal vaccination uptake remains low compared to the general population. OBJECTIVES: An umbrella review to explore the barriers and facilitators to Influenza, Pertussis and COVID-19 vaccination during pregnancy and within 2 years after childbirth, and to inform interventions to encourage uptake (PROSPERO registration number: CRD42022327624). METHODS: Ten databases were searched for systematic reviews published between 2009 and April 2022 exploring the predictors of vaccination or effectiveness of interventions to improve vaccination for Pertussis, Influenza, or COVD-19. Both pregnant women and mothers of infants under two years were included. Barriers and facilitators were organised using the WHO model of determinants of vaccine hesitancy through narrative synthesis, the Joanna Briggs Institute checklist assessed review quality, and the degree of overlap of primary studies was calculated. RESULTS: 19 reviews were included. Considerable overlap was found especially for intervention reviews, and the quality of the included reviews and their primary studies varied. Sociodemographic factors were specifically researched in the context of COVID-19, exerting a small but consistent effect on vaccination. Concerns around the safety of vaccination particularly for the developing baby were a main barrier. While key facilitators included recommendation from a healthcare professional, previous vaccination, knowledge around vaccination, and communication with and support from social groups. Intervention reviews indicated multi-component interventions involving human interaction to be most effective. CONCLUSION: The main barriers and facilitators for Influenza, Pertussis and COVID-19 vaccination have been identified and constitute the foundation for policy development at the international level. Ethnicity, socioeconomic status, concerns about vaccine safety and side effects, and lack of healthcare professionals' recommendations, are the most relevant factors of vaccine hesitancy. Adapting educational interventions to specific populations, person-to-person interaction, healthcare professionals' involvement, and interpersonal support are important strategies to improve uptake.

Surveillance Systems for Monitoring Vaccination Coverage with Vaccines Recommended for Pregnant Women, United States.

Pregnant women* and their infants are at increased risk for serious influenza, pertussis, and COVID-19-related complications, including preterm birth, low-birth weight, and maternal and fetal death. The advisory committee on immunization practices recommends pregnant women receive tetanus-toxoid, reduced diphtheria toxoid, and acellular pertussis (Tdap) vaccine during pregnancy, and influenza and COVID-19 vaccines before or during pregnancy. Vaccination coverage estimates and factors associated with maternal vaccination are measured by various surveillance systems. The objective of this report is to provide a detailed overview of the following surveillance systems that can be used to assess coverage of vaccines recommended for pregnant women: Internet panel survey, National Health Interview Survey, National Immunization Survey-Adult COVID Module, Behavioral Risk Factor Surveillance System, Pregnancy Risk Assessment Monitoring System, Vaccine Safety Datalink, and MarketScan. Influenza, Tdap, and COVID-19 vaccination coverage estimates vary by data source, and select estimates are presented. Each surveillance system differs in the population of pregnant women, time period, geographic area for which estimates can be obtained, how vaccination status is determined, and data collected regarding vaccine-related knowledge, attitudes, behaviors, and barriers. Thus, multiple systems are useful for a more complete understanding of maternal vaccination. Ongoing surveillance from the various systems to obtain vaccination coverage and information regarding disparities and barriers related to vaccination are needed to guide program and policy improvements.

Pertussis in Poland in 2020.

INTRODUCTION: The epidemiological situation of infectious diseases in Poland in 2020, including pertussis cases, was significantly influenced by the limitation of interpersonal contacts introduced to reduce the transmission of SARS-CoV-2 virus. There was a reduction by more than half in the number of recorded pertussis cases, from 1,629 in 2019 to 753 in 2020. Pertussis is most dangerous for young children, however, it can get sick at any age, and the disease does not leave permanent immunity. Severe pertussis can also develop in the elderly, which may increase the risk of mortality. Adults usually have pertussis is mildly symptomatic and constitute an important reservoir of B. pertussis. The most effective strategy for the prevention of pertussis is still immunization of children in accordance with the Protective Vaccination Program, and in the case of adults, vaccination with the pertussis component in acellular form, repeated regularly every 10 years. OBJECTIVES: The aim of the study was to assess the epidemiological situation of pertussis in Poland in 2020 compared to the situation in previous years, with particular emphasis on the assessment of the vaccination status of children against pertussis. MATERIAL AND METHODS: The assessment of the epidemiological situation of pertussis in Poland was performed on the basis of the results of the analysis of unit reports of pertussis registered in the NIPH NIH - NRI in the EpiBaza system and data from the annual bulletin "Infectious diseases and poisonings in Poland in 2020" and the bulletin "Vaccinations in Poland in 2020". RESULTS: In 2020, 753 cases of pertussis were registered. The incidence was 1.96 per 100,000 population and was lower compared to the incidence in 2019 (4.24). The highest incidence of pertussis occurred in the age group 0-4 years (9.9), and high in children and adolescents aged 5-9 years (5.1) and 10-14 years (6.0 per 100,000 population). About half of the cases concerned people over 15 years of age. In general, a higher incidence of women was observed than that of men, as well as a greater number of cases in cities than in rural areas. In 2020, among people suffering from pertussis, 206 people (i.e. 27%) required hospitalization. In 2020, one fatal case of the disease was reported to the epidemiological surveillance system. SUMMARY AND CONCLUSIONS: In Poland, in 2020, there was a decrease in the number of pertussis cases by more than a half compared to the previous year. Despite the decline in disease rates, pertussis remains a public health problem as immunization-induced immunity is not sustained throughout life. Increasing the number of people susceptible to pertussis may lead to compensatory epidemics in the future, therefore the highest possible level of vaccination of the population, >92-94%, should be maintained to prevent new cases of pertussis.

Seroepidemiology of pertussis in the east of China: Estimates of incidence of infection in adolescents and adults pre- and post-COVID-19.

Introduction: The dramatic decrease in the number of reported cases of pertussis during COVID-19 pandemic has been underestimated. The objective was to compare the estimated incidence rate of pertussis in populations pre- and post-COVID-19 pandemic by analyzing the anti-pertussis toxin (anti-PT) IgG and anti-filamentous hemagglutininant (anti-FHA) IgG antibodies in healthy Chinese population from 2018 to 2021. Methods: All serum samples (N = 1,000) were collected from healthy population (aged ≥ 15 years) who attended an annual monitoring project of antibody levels in Jiangsu province in 2018-2021 were measured by ELISA. Results: The positive rates of anti-PT IgG and anti-FHA IgG antibodies were 11.4% (114/1,000) and 20.2% (202/1,000) (≥40 IU/ml), the GMC were 17.25 (95% CI: 15.49-19.03) IU/mL and 24.94 (95% CI: 22.73-27.16) IU/mL in the study population, respectively. The percentage of participants with anti-PT IgG antibodies higher than 40 IU/mL was 5.20% (11/212) in 2018, 5.5% (19/348) in 2019, 21.2% (46/217) in 2020 and 17.0% (38/223) in 2021, respectively. The non-detectable rate (<5 IU/mL) of anti-PT IgG antibodies was 16.9, 17.7, 28.1, and 37.3% in 2018, 2019, 2020, and 2021, respectively. We assumed that the infection occurred within 58.6 days, and based on the overall proportion (2.9%) of individuals with anti-PT IgG antibody ≥100 IU/ml, the incidence rate (/100) was estimated by the formula to be 18.08 (95% CI: 12.40-26.11). In addition, the estimated incidence of Post-COVID-19 was higher than that of Pre-COVID-19 (36.33/100 vs. 12.84/100), and the difference was statistically significant (p < 0.05). Conclusions: Our results suggest a high rate of under-reporting of pertussis in Jiangsu Province both pre- and post-COVID-19 pandemic, and there are a large number of adults of childbearing age who are susceptible to pertussis. It seems imperative that vaccination of adolescents and adults should be considered for inclusion in vaccination programs.

Willingness to get vaccinated against influenza, pneumococcal disease, pertussis, and herpes zoster - A pre-COVID-19 exploration among the older adult population.

BACKGROUND: Older adults are at increased risk for adverse health outcomes when having an influenza, pneumococcal disease, pertussis, or herpes zoster infection. Despite the ability of vaccinations to prevent these adverse outcomes, vaccination coverage is low in the European Union. This study aimed to explore the sociodemographic, lifestyle, and health-related characteristics associated with vaccination willingness for these vaccine-preventable diseases. METHODS: Cross-sectional data from wave 6 (years 2013-2017) of the population-based Doetinchem Cohort Study was analysed, with 3063 participants aged 46-86 years included. The outcome was the self-reported willingness to get vaccinated against influenza, pneumococcal disease, pertussis, and herpes zoster (willing, neutral, not willing). Multinomial logistic regression was used to investigate the socio-demographic, lifestyle and health characteristics associated with vaccination willingness. RESULTS: For influenza 36 % was willing to get vaccinated, 35 % was neutral and 28 % was not willing to get vaccinated. The willingness to get vaccinated for the relatively unfamiliar vaccine-preventable diseases was lower: 26 % for pneumococcal disease (neutral: 50 %, not willing: 23 %), 26 % for pertussis (neutral 53 %, not willing: 22 %), and 23 % for herpes zoster (neutral 54 %, not willing: 24 %). A relative lower willingness was found among those 46-64 years old (compared to those 65 years or older). Women, having a high SES, being employed and having a good health were all associated with lower willingness to get vaccinated, which was the case for all vaccine-preventable diseases. CONCLUSIONS: Older adults were generally more willing to get vaccinated against influenza than for the three less familiar diseases. Characteristics of those less willing may be used to improve strategies to increase vaccination coverage. Additional studies are needed to investigate the willingness to get vaccinated during and after the COVID-19 pandemic that may have changed the feel of urgency for vaccination.

Knowledge and decisions about maternal immunisation by pregnant women in Aotearoa New Zealand.

BACKGROUND: Maternal vaccinations for influenza and pertussis are recommended in New Zealand to protect mothers and their infant from infection. However, maternal immunisation coverage in New Zealand is suboptimal. Furthermore, there is unacceptable inequitable maternal immunisation rates across the country with Maori and Pacific women having significantly lower maternal immunisation rates than those of other New Zealanders. METHODS: This research set out to explore what pregnant/recently pregnant Maori and Pacific women knew about immunisation during pregnancy and what factors influenced their decision to be vaccinated. A semi-structured interview guide was developed with questions focusing on knowledge of pertussis and influenza vaccination during pregnancy and decision-making. Maori and Pacific women aged over 16 years were purposively sampled and interviewed in Dunedin and Gisborne, New Zealand between May and August 2021. Interviews were analysed following a directed qualitative content approach. Data were arranged into coding nodes based on the study aims (deductive analysis) informed by previous literature and within these participant experiences were inductively coded into themes and subthemes. RESULTS: Not all women were aware of maternal vaccine recommendations or they diseases they protected against. Many underestimated how dangerous influenza and pertussis could be and some were more concerned about potential harms of the vaccine. Furthermore, understanding potential harms of infection and protection provided by vaccination did not necessarily mean women would choose to be vaccinated. Those who decided to vaccinate felt well-informed, had vaccination recommended by their healthcare provider, and did so to protect their and their infant's health. Those who decided against vaccination were concerned about safety of the vaccines, lacked the information they needed, were not offered the vaccine, or did not consider vaccination a priority. CONCLUSIONS: There is a lack of understanding about vaccine benefits and risks of vaccine-preventable diseases which can result in the reinforcement of negative influences such as the fear of side effects. Furthermore, if vaccine benefits are not understood, inaccessibility of vaccines and the precedence of other life priorities may prevent uptake. Being well-informed and supported to make positive decisions to vaccinate in pregnancy is likely to improve vaccine coverage in Maori and Pacific Island New Zealanders.

Impact of national COVID-19 restrictions on incidence of notifiable communicable diseases in England: an interrupted time series analysis.

BACKGROUND: Non-pharmaceutical interventions (NPIs), such as travel restrictions, social distancing and isolation policies, aimed at controlling the spread of COVID-19 may have reduced transmission of other endemic communicable diseases, such as measles, mumps and meningitis in England. METHODS: An interrupted time series analysis was conducted to examine whether NPIs was associated with trends in endemic communicable diseases, using weekly reported cases of seven notifiable communicable diseases (food poisoning, measles, meningitis, mumps, scarlet fever and pertussis) between 02/01/2017 to 02/01/2021 for England. RESULTS: Following the introduction of COVID-19 restrictions, there was an 81.1% (95% CI; 77.2-84.4) adjusted percentage reduction in the total number of notifiable diseases recorded per week in England. The greatest decrease was observed for measles, with a 90.5% percentage reduction (95% CI; 86.8-93.1) from 42 to 5 cases per week. The smallest decrease was observed for food poisoning, with a 56.4% (95%CI; 42.5-54.2) decrease from 191 to 83 cases per week. CONCLUSIONS: A total reduction in the incidence of endemic notifiable diseases was observed in England following the implementation of public health measures aimed at reducing transmission of SARS-COV-2 on March 23, 2020. The greatest reductions were observed in diseases most frequently observed during childhood that are transmitted via close human-to-human contact, such as measles and pertussis. A less substantive reduction was observed in reported cases of food poisoning, likely due to dining services (i.e., home deliveries and takeaways) remaining open and providing a potential route of transmission. This study provides further evidence of the effectiveness of non-pharmaceutical public health interventions in reducing the transmission of both respiratory and food-borne communicable diseases.

Effects of Vaccination Against Influenza, Pertussis, and COVID-19 on Human Milk Antibodies: Current Evidence and Implications for Health Equity.

Human milk contains three antibody classes that confer mucosal immunity to the breastfed infant: secretory IgA (SIgA), secretory IgM (SIgM), and IgG. Influenza and pertussis vaccines administered during pregnancy induce pathogen specific SIgA and IgG responses in human milk that have been shown to protect the breastfed infant from these respiratory illnesses. In addition, mRNA vaccines against the SARS-CoV-2 virus administered during pregnancy and lactation induce anti-SARS-CoV-2 IgG and IgA responses in human milk. This review summarizes the immunologic benefits of influenza, pertussis, and COVID-19 vaccines conferred by human milk. Additionally, future research direction in human milk immunity and public health needs to improve lactational support are discussed.

The decline in immunity and circulation of pertussis among Chinese population during the COVID-19 pandemic: A cross-sectional sero-epidemiological study.

BACKGROUND: In recent years, the resurgence of pertussis has posed a public health challenge in many countries. This study aimed to evaluate the immunity levels against pertussis among populations of different ages in China. METHODS: We conducted a cross-sectional serological survey in Zhejiang Province, China in 2020. Serum IgG antibodies against pertussis toxin (anti-PT), filamentous hemagglutinin (anti-FHA), and pertactin (anti-PRN) were quantitatively measured. The geometric mean concentration (GMC) of three antibodies was calculated. An anti-PT level < 5 IU/mL was considered undetectable, ≥20 IU/mL as seropositive and ≥80 IU/mL as an indicator of recent infection. Mathematical models were fitted for anti-PT concentrations over time in children after four doses of the pertussis vaccination. RESULTS: A total of 4459 participants aged 0-59 years were included in the analyses. The overall positivity rate of anti-PT was 29.80% with the highest (81.44%) rate in the 1-2 years old and the lowest (4.72%) in 10-14 years old. The GMCs of anti-PT, anti-FHA and anti-PRN for the whole participants were 9.67 (95%CI: 9.25-10.10),18.93 (18.24-19.67), and 8.99 (8.61-9.38) IU/mL, respectively. Over 50% of subjects aged ≥ 7 years had undetectable anti-PT IgG antibodies (<5IU/mL). The proportions of the populations with anti-PT IgG ≥ 80 IU/mL were approximately 0.9%, 0.3% and 1.1% among the 10-14, 15-29, and 40-59 years old groups, respectively. The power regression equation of the attenuation model after last dose of pertussis vaccine was y = 41.088x-1.238 (R2 = 0.935, p < 0.001). The fitted anti-PT concentrations was only 5.60 IU/mL at 5 years following the last vaccination dose. CONCLUSION: The prevalence of pertussis decreased during the study period in the COVID-19 pandemic; however, there was still a certain proportion of adolescents and adults with evidence of recent infection. The decline in antibody levels after pertussis vaccination was observed, and booster doses are in urgent need in China.

Lessons from a mature acellular pertussis vaccination program and strategies to overcome suboptimal vaccine effectiveness.

INTRODUCTION: Despite high vaccination coverage among children and adolescents, pertussis remains a public health problem, with large outbreaks occurring periodically in the US and other developed countries. AREAS COVERED: We examine lessons learned more than 20 years after implementation of programs which use only acellular pertussis vaccines and propose avenues for possible effective use of acellular pertussis vaccine to prevent large outbreaks. EXPERT OPINION: Acellular pertussis vaccines were introduced more than 20 years ago, yet the incidence of pertussis has been increasing over the past decade, with periodic large outbreaks marked by notable shifts in disease burden from infants and young children toward fully vaccinated adolescents and young adults. This age shift is mainly driven by the waning of vaccine immunity. To better protect adolescents against pertussis, modification of the current acellular pertussis vaccination schedule or adoption of new vaccination strategies should be considered. For infants not yet eligible to be vaccinated, maternal vaccination against pertussis during pregnancy is an effective way to protect infants from infection, severe disease and death. Implementation of maternal vaccination programs should be encouraged in countries without one or efforts to improve coverage should be supported in countries with existing program.

Barriers and facilitators to vaccination for COVID-19, pertussis, and influenza during pregnancy: Protocol for an umbrella review.

Pregnant women are particularly vulnerable to infection. Furthermore, infection from pertussis, influenza and COVID-19 increases the likelihood of adverse consequences to the mother and developing baby such as stillbirth, ICU admission, and pre-term caesarean birth. Increased rates of transmission and risk of adverse consequences from infection justifies the provision of national maternal vaccination programmes. Additionally, maternal vaccination helps protect the infant until they are able to receive their own vaccinations; a time when they are most at risk of mortality from influenza and pertussis. Vaccination during pregnancy has been repeatedly demonstrated as safe and effective in reducing harm, although rates of uptake remain low compared to the general population. The current protocol describes the methodology for an umbrella review aiming to explore the barriers and facilitators of vaccination during pregnancy for pertussis, influenza, and COVID-19. Systematic reviews that investigate the barriers and facilitators of at least one of either pertussis, influenza, or COVID-19 will be included in this review. Multiple databases will be searched, and included reviews assessed for quality (using the Joanna Briggs Institute (JBI) quality assessment for systematic reviews) and degree of overlap of included primary studies. Included reviews will be analysed according to the WHO SAGE model of determinants of vaccine hesitancy and separated by whether these explore influenza and pertussis, or COVID-19. The outcomes of this review will help inform the development of interventions to increase uptake of vaccination during pregnancy, and on whether interventions need to be tailored depending on the infectious disease. The key findings will identify the specific barriers and facilitators of vaccination hesitancy by considering contextual influences (e.g. sociodemographic variables), individual/social group influences (e.g. trust in the institutions), and vaccine-specific issues (e.g. safety and recommendations).