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1.
Vaccine ; 40(32): 4574-4579, 2022 Jul 30.
Article in English | MEDLINE | ID: covidwho-1886123

ABSTRACT

Measles elimination hinges on vaccination coverage remaining above 95% to retain sufficient community protection. Recent declines in routine measles vaccinations due to the COVID-19 pandemic coupled with prior models indicating the country was close to the 92% herd immunity benchmark are a cause for concern. We evaluated population-level measles susceptibility in the US, including sensitivity analyses accounting for pandemic-related impacts on immunization. We estimated the number of children aged 0-18 currently susceptible to measles and modeled susceptibility proportions in decreased vaccination scenarios. Participants were respondents to the NIS-Teen survey between 2008 and 2017 that also had provider-verified vaccination documentation. The exposure of interest was vaccination with a measles-containing vaccine (MCV), and the age at which they were vaccinated for all doses given. Using age at vaccination, we estimated age-based probabilities of vaccination and modeled population levels of MCV immunization and immunity vs. susceptibility. Currently, 9,145,026 children (13.1%) are estimated to be susceptible to measles. With pandemic level vaccination rates, 15,165,221 children (21.7%) will be susceptible to measles if no attempt at catch-up is made, or 9,454,436 children (13.5%) if catch-up vaccinations mitigate the decline by 2-3%. Models based on increased vaccine hesitancy also show increased susceptibility at national levels, with a 10% increase in hesitancy nationally resulting in 14,925,481 children (21.37%) susceptible to measles, irrespective of pandemic vaccination levels. Current levels of measles immunity remain below herd immunity thresholds. If pandemic-era reductions in childhood immunization are not rectified, population-level immunity to measles is likely to decline further.


Subject(s)
COVID-19 , Measles , Adolescent , COVID-19/epidemiology , COVID-19/prevention & control , Child , Disease Susceptibility/epidemiology , Humans , Infant , Measles/epidemiology , Measles/prevention & control , Measles Vaccine , Measles-Mumps-Rubella Vaccine , Pandemics , Vaccination , Vaccination Coverage
2.
Viruses ; 14(5)2022 05 17.
Article in English | MEDLINE | ID: covidwho-1875808

ABSTRACT

Despite the existence of an effective live-attenuated vaccine, measles can appear in vaccinated individuals. We investigated breakthrough measles cases identified during our surveillance activities within the measles/rubella surveillance network (MoRoNet) in Milan and surrounding areas (Northern Italy). Between 2017 and 2021, we confirmed measles virus (genotypes B3 or D8) infections in 653 patients and 51 of these (7.8%) were vaccinees. Among vaccinated individuals whose serum was available, a secondary failure was evidenced in 69.4% (25/36) of cases while 11 patients (30.6%) were non-responders. Non-responders were more frequently hospitalized and had significantly lower Ct values in both respiratory and urine samples. Median age and time since the last immunization were similar in the two groups. Importantly, we identified onward transmissions from vaccine failure cases. Vaccinees were involved in 20 outbreaks, in 10 of them they were able to transmit the virus, and in 8 of them, they were the index case. Comparing viral hemagglutinin sequences from vaccinated and non-vaccinated subjects did not show a specific mutation pattern. These results suggest that vaccination failure was likely due to the poor immune response of single individuals and highlights the importance of identifying breakthrough cases and characterizing their clinical and virologic profiles.


Subject(s)
Measles , Disease Outbreaks/prevention & control , Humans , Italy/epidemiology , Measles/epidemiology , Measles/prevention & control , Measles Vaccine , Measles virus/genetics , Vaccines, Attenuated
3.
Viruses ; 14(6)2022 05 29.
Article in English | MEDLINE | ID: covidwho-1869826

ABSTRACT

Measles virus (MV) is a highly contagious respiratory virus responsible for outbreaks associated with significant morbidity and mortality among children and young adults. Although safe and effective measles vaccines are available, the COVID-19 pandemic has resulted in vaccination coverage gaps that may lead to the resurgence of measles when restrictions are lifted. This puts individuals who cannot be vaccinated, such as young infants and immunocompromised individuals, at risk. Therapeutic interventions are complicated by the long incubation time of measles, resulting in a narrow treatment window. At present, the only available WHO-advised option is treatment with intravenous immunoglobulins, although this is not approved as standard of care. Antivirals against measles may contribute to intervention strategies to limit the impact of future outbreaks. Here, we review previously described antivirals and antiviral assays, evaluate the antiviral efficacy of a number of compounds to inhibit MV dissemination in vitro, and discuss potential application in specific target populations. We conclude that broadly reactive antivirals could strengthen existing intervention strategies to limit the impact of measles outbreaks.


Subject(s)
COVID-19 , Measles , Antiviral Agents/pharmacology , Antiviral Agents/therapeutic use , Child , Humans , Measles Vaccine , Measles virus , Pandemics , Vaccination
4.
Pan Afr Med J ; 41: 104, 2022.
Article in English | MEDLINE | ID: covidwho-1789672

ABSTRACT

Introduction: the COVID-19 outbreak was declared a public health emergency of international concern by the WHO on the 30th January 2020. The occurrence of measles outbreaks in the context of COVID-19, both highly infectious respiratory illnesses, impacts additional challenges to the health system in a state with an ongoing humanitarian crisis. This article documents the implementation of an outbreak response immunization (ORI) during the COVID-19 pandemic and the implementation of global guidelines for mass vaccination. Methods: a retrospective review of the response to measles outbreak implemented in Borno state across six local government areas (LGAs) in 2019 was conducted. This review assessed the utilization of the World Health Organization (WHO) decision making framework, measles and COVID-19 epidemiological reports and the measle's vaccination response data. Results: an outbreak response immunization was implemented in six LGAs in Borno State, with a validated post campaign coverage of 96.3% (95% CI: 93.0 - 98.1). In total, 181,634 children aged 9 months-9 years were vaccinated with 27,961 (15.4%) receiving the measles vaccine for the first time. Prior to the interventions, 20 COVID-19 cases were reported in the six LGAs while only seven suspected cases were reported with only two cases confirmed in one of the six LGAs four weeks after the ORI. Conclusion: the WHO decision-making framework for implementing mass vaccinations in the context of the COVID-19 Pandemic was utilized for the outbreak response immunization in Borno State, Nigeria with 181,634 children aged 9 Months-9 years vaccinated with the measles vaccine. The use of the WHO decision-making framework to assess risk benefits of initiating mass vaccination campaigns remains a very important practical tool. These types of responses in Nigeria and other low and middle income countries (LMICs), with hitherto suboptimal immunization coverage and weak health systems and other settings, affected by humanitarian emergencies is essential in the achievement of the regional measle's elimination targets.


Subject(s)
COVID-19 , Measles , COVID-19/prevention & control , Child , Disease Outbreaks/prevention & control , Humans , Immunization , Immunization Programs , Infant , Mass Vaccination , Measles/epidemiology , Measles/prevention & control , Measles Vaccine , Nigeria/epidemiology , Pandemics , Vaccination
5.
Indian J Public Health ; 66(1): 71-73, 2022.
Article in English | MEDLINE | ID: covidwho-1776447

ABSTRACT

India, as a member of the World Health Organization South-East Asia Region, had committed to measles elimination by 2020. Efforts to increase immunization coverage, special immunization activities, and case-based surveillance have been implemented rigorously over the last 7 years, but India has not been able to eliminate measles. Multiple factors led to this namely inadequate vaccination coverage and COVID pandemic and others. The pandemic added its contribution in disruption of vaccine delivery services under Intensified Mission Indradhanush preventing the achievement of the elimination target, in stipulated time. India may need to think beyond strengthening the routine immunization activities and increasing the geographical coverage under Intensified Mission Indradhanush. Promising the future in the measles vaccine delivery system in the form of Measles-Micro-Array-Patches is seen on the horizon may prove to be a game-changer for targeting measles elimination, in the current decade.


Subject(s)
COVID-19 , Measles , Humans , Immunization Programs , India/epidemiology , Measles/epidemiology , Measles/prevention & control , Measles Vaccine , Population Surveillance , Vaccination
6.
Lancet ; 399(10325): 678-690, 2022 02 12.
Article in English | MEDLINE | ID: covidwho-1721141

ABSTRACT

Measles is a highly contagious, potentially fatal, but vaccine-preventable disease caused by measles virus. Symptoms include fever, maculopapular rash, and at least one of cough, coryza, or conjunctivitis, although vaccinated individuals can have milder or even no symptoms. Laboratory diagnosis relies largely on the detection of specific IgM antibodies in serum, dried blood spots, or oral fluid, or the detection of viral RNA in throat or nasopharyngeal swabs, urine, or oral fluid. Complications can affect many organs and often include otitis media, laryngotracheobronchitis, pneumonia, stomatitis, and diarrhoea. Neurological complications are uncommon but serious, and can occur during or soon after the acute disease (eg, acute disseminated encephalomyelitis) or months or even years later (eg, measles inclusion body encephalitis and subacute sclerosing panencephalitis). Patient management mainly involves supportive therapy, such as vitamin A supplementation, monitoring for and treatment of secondary bacterial infections with antibiotics, and rehydration in the case of severe diarrhoea. There is no specific antiviral therapy for the treatment of measles, and disease control largely depends on prevention. However, despite the availability of a safe and effective vaccine, measles is still endemic in many countries and causes considerable morbidity and mortality, especially among children in resource-poor settings. The low case numbers reported in 2020, after a worldwide resurgence of measles between 2017 and 2019, have to be interpreted cautiously, owing to the effect of the COVID-19 pandemic on disease surveillance. Disrupted vaccination activities during the pandemic increase the potential for another resurgence of measles in the near future, and effective, timely catch-up vaccination campaigns, strong commitment and leadership, and sufficient resources will be required to mitigate this threat.


Subject(s)
COVID-19/epidemiology , Endemic Diseases/prevention & control , Mass Vaccination/organization & administration , Measles Vaccine/administration & dosage , Measles/prevention & control , COVID-19/prevention & control , Communicable Disease Control/organization & administration , Communicable Disease Control/standards , Endemic Diseases/statistics & numerical data , Humans , Mass Vaccination/standards , Mass Vaccination/statistics & numerical data , Measles/epidemiology , Measles/immunology , Measles/virology , Measles virus/immunology , Measles virus/pathogenicity , Pandemics/prevention & control
8.
BMC Public Health ; 22(1): 221, 2022 02 03.
Article in English | MEDLINE | ID: covidwho-1707500

ABSTRACT

BACKGROUND: Following the 2015 earthquake, a measles-rubella (MR) supplementary immunization activity (SIA), in four phases, was implemented in Nepal in 2015-2016. A post-campaign coverage survey (PCCS) was then conducted in 2017 to assess SIA performance and explore factors that were associated with vaccine uptake. METHODS: A household survey using stratified multi-stage probability sampling was conducted to assess coverage for a MR dose in the 2015-2016 SIA in Nepal. Logistic regression was then used to identify factors related to vaccine uptake. RESULTS: Eleven thousand two hundred fifty-three households, with 4870 eligible children provided information on vaccination during the 2015-2016 MR SIA. Overall coverage of measles-rubella vaccine was 84.7% (95% CI: 82.0-87.0), but varied between 77.5% (95% CI: 72.0, 82.2) in phase-3, of 21 districts vaccinated in Feb-Mar 2016, to 97.7% (CI: 95.4, 98.9) in phase-4, of the last seven mountainous districts vaccinated in Mar-Apr 2016. Coverage in rural areas was higher at 85.6% (CI: 81.9, 88.8) than in urban areas at 79.0% (CI: 75.5, 82.1). Of the 4223 children whose caregivers knew about the SIA, 96.5% received the MR dose and of the 647 children whose caregivers had not heard about the campaign, only 1.8% received the MR dose. CONCLUSIONS: The coverage in the 2015-2016 MR SIA in Nepal varied by geographical region with rural areas achieving higher coverage than urban areas. The single most important predictor of vaccination was the caregiver being informed in advance about the vaccination campaign. Enhanced efforts on social mobilization for vaccination have been used in Nepal since this survey, notably for the most recent 2020 MR campaign.


Subject(s)
Measles , Rubella , Child , Humans , Immunization Programs , Infant , Measles/epidemiology , Measles/prevention & control , Measles Vaccine , Nepal/epidemiology , Rubella/prevention & control , Rubella Vaccine , Vaccination
9.
Lancet ; 398(10299): 522-534, 2021 08 07.
Article in English | MEDLINE | ID: covidwho-1592159

ABSTRACT

BACKGROUND: The COVID-19 pandemic and efforts to reduce SARS-CoV-2 transmission substantially affected health services worldwide. To better understand the impact of the pandemic on childhood routine immunisation, we estimated disruptions in vaccine coverage associated with the pandemic in 2020, globally and by Global Burden of Disease (GBD) super-region. METHODS: For this analysis we used a two-step hierarchical random spline modelling approach to estimate global and regional disruptions to routine immunisation using administrative data and reports from electronic immunisation systems, with mobility data as a model input. Paired with estimates of vaccine coverage expected in the absence of COVID-19, which were derived from vaccine coverage models from GBD 2020, Release 1 (GBD 2020 R1), we estimated the number of children who missed routinely delivered doses of the third-dose diphtheria-tetanus-pertussis (DTP3) vaccine and first-dose measles-containing vaccine (MCV1) in 2020. FINDINGS: Globally, in 2020, estimated vaccine coverage was 76·7% (95% uncertainty interval 74·3-78·6) for DTP3 and 78·9% (74·8-81·9) for MCV1, representing relative reductions of 7·7% (6·0-10·1) for DTP3 and 7·9% (5·2-11·7) for MCV1, compared to expected doses delivered in the absence of the COVID-19 pandemic. From January to December, 2020, we estimated that 30·0 million (27·6-33·1) children missed doses of DTP3 and 27·2 million (23·4-32·5) children missed MCV1 doses. Compared to expected gaps in coverage for eligible children in 2020, these estimates represented an additional 8·5 million (6·5-11·6) children not routinely vaccinated with DTP3 and an additional 8·9 million (5·7-13·7) children not routinely vaccinated with MCV1 attributable to the COVID-19 pandemic. Globally, monthly disruptions were highest in April, 2020, across all GBD super-regions, with 4·6 million (4·0-5·4) children missing doses of DTP3 and 4·4 million (3·7-5·2) children missing doses of MCV1. Every GBD super-region saw reductions in vaccine coverage in March and April, with the most severe annual impacts in north Africa and the Middle East, south Asia, and Latin America and the Caribbean. We estimated the lowest annual reductions in vaccine delivery in sub-Saharan Africa, where disruptions remained minimal throughout the year. For some super-regions, including southeast Asia, east Asia, and Oceania for both DTP3 and MCV1, the high-income super-region for DTP3, and south Asia for MCV1, estimates suggest that monthly doses were delivered at or above expected levels during the second half of 2020. INTERPRETATION: Routine immunisation services faced stark challenges in 2020, with the COVID-19 pandemic causing the most widespread and largest global disruption in recent history. Although the latest coverage trajectories point towards recovery in some regions, a combination of lagging catch-up immunisation services, continued SARS-CoV-2 transmission, and persistent gaps in vaccine coverage before the pandemic still left millions of children under-vaccinated or unvaccinated against preventable diseases at the end of 2020, and these gaps are likely to extend throughout 2021. Strengthening routine immunisation data systems and efforts to target resources and outreach will be essential to minimise the risk of vaccine-preventable disease outbreaks, reach children who missed routine vaccine doses during the pandemic, and accelerate progress towards higher and more equitable vaccination coverage over the next decade. FUNDING: Bill & Melinda Gates Foundation.


Subject(s)
COVID-19 , Diphtheria-Tetanus-Pertussis Vaccine , Measles Vaccine , Vaccination Coverage/statistics & numerical data , Child , Global Health , Humans , Models, Statistical
10.
Lancet Glob Health ; 10(2): e288-e292, 2022 02.
Article in English | MEDLINE | ID: covidwho-1586171

ABSTRACT

Measles virus and respiratory syncytial virus (RSV) are two important global health pathogens causing substantial morbidity and mortality worldwide. The current measles vaccination schedule has the first dose given at 9-12 months of age and the second dose given at 15-18 months of age. Measles outbreaks have been associated with an increase in severe RSV infections in children younger than 6 months, probably as a result of measles-induced immunosuppression. A resurgence in measles cases was already occurring before the COVID-19 pandemic, which has affected global immunisation programmes, resulting in millions of children, mostly in low-income and middle-income countries (LMICs), missing out on their measles vaccine. This will leave many children living in the most vulnerable of circumstances highly susceptible to measles and RSV infections when current COVID-19 public health control measures are lifted. This Viewpoint discusses these issues and highlights the need for urgent action to address this looming crisis. The use of early measles vaccination at 4 months of age could be an effective strategy to prevent severe morbidity and death from both measles and RSV infections in many LMICs.


Subject(s)
Measles Vaccine/administration & dosage , Measles/prevention & control , Respiratory Syncytial Virus Infections/prevention & control , COVID-19/epidemiology , Developing Countries , Global Health , Humans , Immunocompetence/immunology , Measles/complications , Pandemics , Respiratory Syncytial Virus, Human , SARS-CoV-2
11.
Hum Vaccin Immunother ; 18(1): 2007707, 2022 12 31.
Article in English | MEDLINE | ID: covidwho-1585259

ABSTRACT

Response measures to mitigate the coronavirus disease 2019 pandemic impacted access to routine vaccination services. We evaluate the impact of the pandemic on routine infant vaccination uptake by comparing vaccination coverage, vaccine delays and doses administered in 2019 and 2020, in Quebec, Canada. Using a population-based vaccination registry, we compared vaccination coverage at 3, 5, 13 and 19 months of age between 2019 and 2020 cohorts each month from January to November. For vaccine delays, we measured the cumulative proportion vaccinated in each targeted cohort monthly. We also compared the measles-containing vaccines administered before 24 months of age between the same period in 2019 and 2020. A decline in vaccination coverage and children vaccinated on time was observed in all cohorts during the first months of the pandemic. The greatest impact was observed for the 18-month vaccination visit with a difference in vaccination coverage between both cohorts of 30.9% in May. Measles-containing doses administered during the first months of the pandemic were lower in 2020 compared with 2019: -21.1% in March (95%CI-21.6;-20.4), and -39.2% in April (95%CI-40.0;-38.2). After May, the coverage increased for all cohorts to reach pre-pandemic levels after a few months for most target ages. Routine childhood vaccinations were affected during the first months of the pandemic, but catch-up occurred thereafter and vaccination coverage in affected cohorts were very close to levels of 2019 after a few months of follow-up. Real-time monitoring of childhood vaccination is essential but also for other vaccination programs, severely affected by the pandemic.


Subject(s)
COVID-19 , COVID-19/epidemiology , COVID-19/prevention & control , Child , Humans , Immunization Programs , Infant , Measles Vaccine , Pandemics , Quebec/epidemiology , Vaccination , Vaccination Coverage
12.
Biomed Res Int ; 2021: 6995096, 2021.
Article in English | MEDLINE | ID: covidwho-1573872

ABSTRACT

At the beginning of the COVID-19 pandemic, early modelling studies estimated a reduction in childhood vaccinations in low- and middle-income countries. Regular provision of both curative and preventive services such as antenatal care and childhood immunizations has been negatively affected since the onset of the pandemic. Our study was aimed at examining the impact that the pandemic had on childhood vaccination services at the Tamale Teaching Hospital (TTH). A mixed methods study design was employed for the study, which was conducted at the Child Welfare Clinic (CWC) of the TTH. With quantitative approach, we retrospectively looked at the uptake of the various vaccines during the pandemic era, defined as the period between 1st March 2020 and 28th February, 2021, and the prepandemic era defined as the period 1st March 2019 to 29th February, 2020. The qualitative approach was used to understand the perspective of five healthcare providers at the CWC and the four caregivers of children who have missed a vaccine or delayed in coming, on the factors accounting for any observed change. Data analysis was done using Microsoft Excel 2016 and thematic content analysis. Quantitative data were presented in frequencies, percentages, and line graphs. With the exception of the Measles Rubella (MR) 2 vaccine, we observed a decline ranging from 47% (2298) to 10.5% (116), with the greatest decline seen in the BCG and the least decline seen in the MR1 vaccine. The month of May 2020 saw the greatest decline, that is, 70.6% (813). A decline of 38.3% (4473) was noted when comparison was made between the designated prepandemic and pandemic eras, for all the vaccines in our study. Fear of COVID-19 infection and misinformation were commonly given as reasons for the decline. Catch-up immunization schedule should be instituted to curtail possible future outbreaks of vaccine-preventable diseases.


Subject(s)
Immunization Programs/trends , Vaccination/trends , BCG Vaccine , COVID-19/complications , COVID-19/psychology , Female , Ghana/epidemiology , Humans , Infant , Infant, Newborn , Male , Measles Vaccine , Pandemics , Pregnancy , Retrospective Studies , Tertiary Care Centers/trends
13.
MMWR Morb Mortal Wkly Rep ; 70(45): 1563-1569, 2021 Nov 12.
Article in English | MEDLINE | ID: covidwho-1513269

ABSTRACT

In 2012, the World Health Assembly endorsed the Global Vaccine Action Plan,* with the objective of eliminating measles† in five of the six World Health Organization (WHO) regions by 2020 (1). The Immunization Agenda 2021-2030 (IA2030)§ uses measles incidence as an indicator of the strength of immunization systems. The Measles-Rubella Strategic Framework 2021-2030¶ and the Measles Outbreaks Strategic Response Plan 2021-2023** are aligned with the IA2030 and highlight robust measles surveillance systems to document immunity gaps, identify root causes of undervaccination, and develop locally tailored solutions to ensure administration of 2 doses of measles-containing vaccine (MCV) to all children. This report describes progress toward World Health Assembly milestones and measles elimination objectives during 2000-2020 and updates a previous report (2). During 2000-2010, estimated MCV first dose (MCV1) coverage increased globally from 72% to 84%, peaked at 86% in 2019, but declined to 84% in 2020 during the COVID-19 pandemic. All countries conducted measles surveillance, although fewer than one third achieved the sensitivity indicator target of ≥2 discarded†† cases per 100,000 population in 2020. Annual reported measles incidence decreased 88% during 2000-2016, from 145 to 18 cases per 1 million population, rebounded to 120 in 2019, before falling to 22 in 2020. During 2000-2020, the annual number of estimated measles deaths decreased 94%, from 1,072,800 to 60,700, averting an estimated 31.7 million measles deaths. To achieve regional measles elimination targets, enhanced efforts are needed to reach all children with 2 MCV doses, implement robust surveillance, and identify and close immunity gaps.


Subject(s)
Disease Eradication , Global Health/statistics & numerical data , Measles/prevention & control , Child , Humans , Immunization Programs , Incidence , Infant , Measles/epidemiology , Measles Vaccine/administration & dosage , World Health Organization
14.
MMWR Morb Mortal Wkly Rep ; 70(43): 1495-1500, 2021 10 29.
Article in English | MEDLINE | ID: covidwho-1498052

ABSTRACT

Endorsed by the World Health Assembly in 2020, the Immunization Agenda 2030 (IA2030) strives to reduce morbidity and mortality from vaccine-preventable diseases across the life course (1). This report, which updates a previous report (2), presents global, regional,* and national vaccination coverage estimates and trends as of 2020. Changes are described in vaccination coverage and the numbers of unvaccinated and undervaccinated children as measured by receipt of the first and third doses of diphtheria, tetanus, and pertussis-containing vaccine (DTP) in 2020, when the COVID-19 pandemic began, compared with 2019. Global estimates of coverage with the third dose of DTP (DTP3) and a polio vaccine (Pol3) decreased from 86% in 2019 to 83% in 2020. Similarly, coverage with the first dose of measles-containing vaccine (MCV1) dropped from 86% in 2019 to 84% in 2020. The last year that coverage estimates were at 2020 levels was 2009 for DTP3 and 2014 for both MCV1 and Pol3. Worldwide, 22.7 million children (17% of the target population) were not vaccinated with DTP3 in 2020 compared with 19.0 million (14%) in 2019. Children who did not receive the first DTP dose (DTP1) by age 12 months (zero-dose children) accounted for 95% of the increased number. Among those who did not receive DTP3 in 2020, approximately 17.1 million (75%) were zero-dose children. Global coverage decreased in 2020 compared with 2019 estimates for the completed series of Haemophilus influenzae type b (Hib), hepatitis B vaccine (HepB), human papillomavirus vaccine (HPV), and rubella-containing vaccine (RCV). Full recovery from COVID-19-associated disruptions will require targeted, context-specific strategies to identify and catch up zero-dose and undervaccinated children, introduce interventions to minimize missed vaccinations, monitor coverage, and respond to program setbacks (3).


Subject(s)
Global Health , Vaccination Coverage/statistics & numerical data , Vaccines/administration & dosage , Adolescent , Child , Child, Preschool , Diphtheria-Tetanus-Pertussis Vaccine/administration & dosage , Goals , Humans , Immunization Programs , Immunization Schedule , Infant , Measles Vaccine/administration & dosage , Poliovirus Vaccines/administration & dosage , World Health Organization
15.
Nat Commun ; 12(1): 6277, 2021 11 01.
Article in English | MEDLINE | ID: covidwho-1493102

ABSTRACT

Several COVID-19 vaccines have now been deployed to tackle the SARS-CoV-2 pandemic, most of them based on messenger RNA or adenovirus vectors.The duration of protection afforded by these vaccines is unknown, as well as their capacity to protect from emerging new variants. To provide sufficient coverage for the world population, additional strategies need to be tested. The live pediatric measles vaccine (MV) is an attractive approach, given its extensive safety and efficacy history, along with its established large-scale manufacturing capacity. We develop an MV-based SARS-CoV-2 vaccine expressing the prefusion-stabilized, membrane-anchored full-length S antigen, which proves to be efficient at eliciting strong Th1-dominant T-cell responses and high neutralizing antibody titers. In both mouse and golden Syrian hamster models, these responses protect the animals from intranasal infectious challenge. Additionally, the elicited antibodies efficiently neutralize in vitro the three currently circulating variants of SARS-CoV-2.


Subject(s)
COVID-19 Vaccines/immunology , COVID-19/immunology , Genetic Vectors , Immunity , Adenoviridae , Animals , Antibodies, Neutralizing/immunology , Antibodies, Viral/immunology , COVID-19/prevention & control , COVID-19 Vaccines/administration & dosage , Cricetinae , Cytokines , Female , Immunization , Immunization, Secondary , Male , Measles Vaccine/immunology , Mesocricetus , Mice , SARS-CoV-2/genetics , Spike Glycoprotein, Coronavirus/genetics , Spike Glycoprotein, Coronavirus/immunology
16.
PLoS One ; 16(10): e0258961, 2021.
Article in English | MEDLINE | ID: covidwho-1484862

ABSTRACT

INTRODUCTION: In 2011, member states of the World Health Organization (WHO) Africa Regional Office (AFRO) resolved to eliminate Measles by 2020. Our study aims to assess The Gambia's progress towards the set AFRO measles elimination target and highlight surveillance and immunisation gaps to better inform future measles prevention strategies. MATERIAL AND METHODS: A retrospective review of measles surveillance data for the period 2011-2019, was extracted from The Gambia case-based measles surveillance database. WHO-UNICEF national coverage estimates were used for estimating national level MCV coverage. Measles post campaign coverage survey coverage estimates were used to estimate national measles campaign coverage. RESULTS: One hundred and twenty-five of the 863 reported suspected cases were laboratory confirmed as measles cases. More than half (53.6%) of the confirmed cases have unknown vaccination status, 24% of cases were vaccinated, 52.8% of cases occurred among males, and 72.8% cases were among urban residents. The incidence of measles cases per million population was lowest (0) in 2011-2012 and highest in 2015 and 2016 (31 and 23 respectively). The indicator for surveillance sensitivity was met in all years except in 2016 and 2019. Children aged 5-9 years (Incidence Rate Ratio-IRR = 0.6) and residents of Central River region (IRR = 0.21) had lower measles risk whilst unvaccinated (Adjusted IRR = 5.95) and those with unknown vaccination status (IRR 2.21) had higher measles risk. Vaccine effectiveness was 89.5%. CONCLUSION: The Gambia's quest to attain measles elimination status by 2020 has registered significant success but it is unlikely that all target indicators will be met. Vaccination has been very effective in preventing cases. There is variation in measles risk by health region, and it will be important to take it into account when designing prevention and control strategies. The quality of case investigations should be improved to enhance the quality of surveillance for decision making.


Subject(s)
Immunization Programs , Measles Vaccine/therapeutic use , Measles/epidemiology , Vaccination Coverage , Adolescent , Adult , Child , Child, Preschool , Disease Eradication , Female , Gambia/epidemiology , Humans , Incidence , Infant , Infant, Newborn , Male , Measles/prevention & control , Population Surveillance , Retrospective Studies
17.
Viruses ; 13(10)2021 10 02.
Article in English | MEDLINE | ID: covidwho-1465472

ABSTRACT

The MMR vaccination program was introduced in Spain in 1981. Consistently high vaccination coverage has led to Spain being declared free of endemic measles transmission since 2014. A few imported and import-related cases were reported during the post-elimination phase (2014 to 2020), with very low incidence: three cases per million of inhabitants a year, 70% in adults. In the post-elimination phase an increasing proportion of measles appeared in two-dose vaccinated individuals (up to 14%), posing a challenge to surveillance and laboratory investigations. Severity and clinical presentation were milder among the vaccinated. The IgM response varied and the viral load decreased, making the virus more difficult to detect. A valid set of samples (serum, urine and throat swab) is strongly recommended for accurate case classification. One third of measles in fully vaccinated people was contracted in healthcare settings, mainly in doctors and nurses, consistent with the important role of high intensity exposure in measles breakthrough cases. Surveillance protocols and laboratory algorithms should be adapted in advanced elimination settings. Reinforcing the immunity of people working in high exposure environments, such as healthcare settings, and implementing additional infection control measures, such as masking and social distancing, are becoming crucial for the global aim of measles eradication.


Subject(s)
Measles/diagnosis , Measles/epidemiology , Adolescent , Child , Child, Preschool , Disease Outbreaks/prevention & control , Epidemiological Monitoring , Female , Humans , Infant , Infant, Newborn , Male , Measles/prevention & control , Measles Vaccine/immunology , Measles Vaccine/pharmacology , Measles virus/pathogenicity , Morbillivirus/pathogenicity , Spain/epidemiology , Vaccination/trends , Vaccination Coverage/statistics & numerical data , Vaccination Coverage/trends , Young Adult
18.
Pan Afr Med J ; 39: 192, 2021.
Article in English | MEDLINE | ID: covidwho-1405544

ABSTRACT

INTRODUCTION: following the declaration of the COVID-19 pandemic, many countries imposed restrictions on public gatherings, health workers were repurposed for COVID-19 response, and public demand for preventive health services declined due to fear of getting COVID-19 in health care settings. These factors led to the disruption in health service delivery, including childhood immunization, in the first months of the pandemic. Measles surveillance supported with laboratory confirmation, is implemented in the African Region as part of the strategies towards attaining measles elimination. World Health Organisation developed guidelines to assist countries to continue to safely provide essential health services including immunization and the surveillance of vaccine preventable diseases during the pandemic. METHODS: we analysed the measles case-based surveillance and laboratory databases for the years 2014 to 2020, to determine the impact of the COVID-19 pandemic on measles surveillance, comparing the performance in 2020 against the preceding years. RESULTS: the weekly reporting of suspected measles cases declined starting in April 2020. Twelve countries had more than 50% decline in both the number of reported cases as well as in the number of specimens collected in 2020, as compared to the mean for the years 2014-2018. In 2020, only 30% of the specimens from suspected measles cases arrived at the national laboratory within 3 days of collection. At Regional level, 86% of the districts reported suspected measles cases in 2020, while the non-measles febrile rash illness rate was 2.1 per 100,000 population, which was the lowest rate documented since 2014. Only 11 countries met the targets for the two principal surveillance performance indicators in 2020 as compared to an average of 21 countries in the years 2014-2019. CONCLUSION: the overall quality of measles surveillance has declined during the COVID pandemic in many countries. Countries should implement immediate and proactive measures to revitalise active surveillance for measles and monitor the quality of surveillance. We recommend that countries consider implementing specimen collection and testing methods that can facilitate timely confirmation of suspected measles cases in remote communities and areas with transportation challenges.


Subject(s)
COVID-19 , Measles/epidemiology , Population Surveillance/methods , Africa/epidemiology , Humans , Immunization Programs , Measles/prevention & control , Measles Vaccine/administration & dosage , Vaccination , World Health Organization
19.
Front Immunol ; 12: 680506, 2021.
Article in English | MEDLINE | ID: covidwho-1325529

ABSTRACT

It has been proven that post-vaccination immunity to measles virus after two doses of vaccine is not able to persistently protect against infection throughout life. The goal of this research was to determine the immune layer to the measles virus among women in labor and maternity ward personnel in the same medical institution. The levels of IgG antibodies to measles virus in the umbilical cord blood of 594 women in labor and 88 workers of the maternity ward were studied by ELISA. It was revealed that 22.7% of umbilical cord blood serum samples from parturient women and 21.4% of blood serum samples from maternity ward personnel were seronegative (<0.18 IU/ml). Levels of IgG antibodies to measles virus in low values (<1.0 IU/ml) were detected in 67% of blood serum samples among women in labor and 68.9% among employees of the maternity ward. Among women in labor, women under 35 years of age are at the highest risk of contracting measles; the proportion of women with low levels of protective antibodies in this age group was almost 70%, and the proportion of women without protective levels of antibodies was 23%. Compared with the age group 36-43, the age of women in labor under 35 was associated with a higher chance of not having immune protection against infection with measles virus OR [95% CI] = 2.2 [1.1-4.5] (p = 0.02) or had a low level of protection OR [95% CI] = 1.9 [1.2-3.0] (p = 0.001). It was also found that among women over 35 years of age, the proportion of persons with a high level of antibodies in women in labor was statistically significantly higher than among members of the maternity ward staff (13 and 0%, respectively, p = 0.007). Thus, maternity ward employees and women in labor constitute a risk group for measles due to the presence of a high proportion of seronegative persons among women of childbearing age (both maternity ward employees and women in labor). These conditions create the need to revise current approaches to present vaccination procedures, especially in the current epidemiological situation with COVID-19.


Subject(s)
Antibodies, Viral/blood , Measles virus/immunology , Measles/prevention & control , Obstetrics and Gynecology Department, Hospital/statistics & numerical data , Adult , Age Distribution , Female , Health Personnel , Humans , Immunoglobulin G/blood , Measles/blood , Measles Vaccine/immunology , Middle Aged , Pregnancy , Young Adult
20.
Hum Vaccin Immunother ; 18(1): 1-6, 2022 12 31.
Article in English | MEDLINE | ID: covidwho-1297359

ABSTRACT

With unprecedented speed, multiple vaccines against SARS-CoV-2 are available 1 year after the COVID-19 pandemic was first identified. As we push to achieve global control through these new vaccines, old challenges present themselves, including cold-chain storage, the logistics of mass vaccination, and vaccine hesitancy. Understanding how much hesitancy toward COVID-19 vaccines might occur and what factors may be driving these concerns can improve the ability of public health workers and communicators to maximize vaccine uptake. We nested a survey within a measles-rubella mass vaccination campaign in Zambia in November 2020 and asked about sentiments and beliefs toward COVID-19 and COVID-19 vaccines. Among parents bringing their children to receive a measles-rubella vaccine, we found high acceptability of COVID-19 vaccination of their children, but substantial uncertainty and hesitancy about receiving the vaccine themselves. COVID-19 vaccination hesitancy was correlated with beliefs around COVID-19 severity and risk, as well as vaccine safety and effectiveness.


Subject(s)
COVID-19 , Vaccines , COVID-19/prevention & control , COVID-19 Vaccines , Child , Humans , Mass Vaccination , Measles Vaccine , Pandemics , SARS-CoV-2 , Vaccination , Zambia/epidemiology
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