The importance of supplementary immunisation activities to prevent measles outbreaks during the COVID-19 pandemic in Kenya

Mburu, Caroline; Ojal, John; Chebet, R.; Akech, Donald; Karia, Boniface; Tuju, James; Sigilai, Antipa; Abbas, Kaja; Jit, Mark; Funk, Sebastian; Smits, Gaby; Gageldonk, Pieter G. M. van; Klis, Fiona R.M. van der; Tabu, Collins; Nokes, D. James; Scott, John A.; Adetifa, Ifedayo

doi:10.1101/2020.08.25.20181198

Cited by 5 publications

(6 citation statements)

References 22 publications

(34 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This risk rises again rapidly once travel restrictions and physical distancing are relaxed, thereby underlying the significance of implementing postponed immunisation campaigns at the earliest to prevent measles outbreaks as COVID-19 restrictions are lifted. 15…”

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Impact of COVID-19-related disruptions to measles, meningococcal A, and yellow fever vaccination in 10 countries

Gaythorpe

Abbas

Huber

et al. 2021

Preprint

Self Cite

View full text Add to dashboard Cite

SummaryBackgroundChildhood immunisation services have been disrupted by the COVID-19 pandemic. WHO recommends considering outbreak risk using epidemiological criteria when deciding whether to conduct preventive vaccination campaigns during the pandemic.MethodsWe used 2-3 models per infection to estimate the health impact of 50% reduced routine vaccination coverage in 2020 and delay of campaign vaccination from 2020 to 2021 for measles vaccination in Bangladesh, Chad, Ethiopia, Kenya, Nigeria, and South Sudan, for meningococcal A vaccination in Burkina Faso, Chad, Niger, and Nigeria, and for yellow fever vaccination in the Democratic Republic of Congo, Ghana, and Nigeria. Our counterfactual comparative scenario was sustaining immunisation services at coverage projections made prior to COVID-19 (i.e. without any disruption).FindingsReduced routine vaccination coverage in 2020 without catch-up vaccination may lead to an increase in measles and yellow fever disease burden in the modelled countries. Delaying planned campaigns in Ethiopia and Nigeria by a year may significantly increased the risk of measles outbreaks (both countries did complete their SIAS planned for 2020). For yellow fever vaccination, delay in campaigns leads to a potential disease burden rise of >1 death per 100,000 people until the campaigns are implemented. For meningococcal A vaccination, short term disruptions in 2020 are unlikely to have a significant impact due to the persistence of direct and indirect benefits from past introductory campaigns of the 1 to 29-year-old population, bolstered by inclusion of the vaccine into the routine immunisation schedule accompanied by further catch-up campaigns.InterpretationThe impact of COVID-19-related disruption to vaccination programs varies between infections and countries. Planning and implementation of campaigns should consider country and infection-specific epidemiological factors and local immunity gaps worsened by the COVID-19 pandemic when prioritising vaccines and strategies for catch-up vaccination.FundingBill & Melinda Gates Foundation and Gavi, the Vaccine AllianceResearch in contextEvidence before the studyWe searched PubMed for (COVID-19 OR coronavirus OR SARS-CoV-2) AND (child health intervention OR vaccin* or immuni*) AND (disruption OR suspension OR reduction) AND (indirect effect OR health impact) on January 14, 2021, with no language restrictions. We found 178 articles of which 13 articles were relevant. Six articles reported some empirical data on immunization disruption in Bangladesh, Japan, Kenya, Nigeria, Pakistan, Saudi Arabia, South Africa, Spain and Italy, and a survey study focussed on immunization disruption in low and middle-income countries. One article proposed using the WHO health systems framework to assess the effects of COVID-19 on immunisation programmes in South Africa, another study on leveraging systems thinking and implementation science to improve immunization system performance in Africa, and two studies were review articles. One modelling study focused on the indirect effects, including reduction in routine immunisation services, of the COVID-19 pandemic on maternal and child mortality in low-income and middle-income countries. Another modelling study focused on a benefit-risk analysis of routine childhood immunisation during the COVID-19 pandemic in Africa. We also found one other study in the grey literature that analysed the impact on SARS-CoV-2 infections as a result of fixed-post and door-to-door vaccination campaigns targeted at children under five years of age in an Ethiopia-like setting.Added value of this studyWe estimated the increase in cases and deaths caused by the disruption to immunisation services leading to outbreaks for measles, meningococcal A and yellow fever in 10 countries. The reduction in routine immunisation coverage among under-immunised cohorts of children has enhanced the risk of outbreaks which cannot be averted without catch-up vaccination. This can lead to an increase of 9.89% (0.91 additional deaths per 100,000 individuals, or 48,000 in total) across the three diseases from 2020 to 2030 in the countries considered. Results vary by infection and country, but generally most excess deaths are due to measles. Postponing campaign immunisation may not have a detrimental short-term health impact if campaign immunisation is implemented ahead of future outbreaks caused by these immunity gaps.Implications of the available evidenceThe COVID-19 pandemic has caused significant disruptions to routine services and vaccination campaigns and resulted in immunity gaps with potential to cause outbreaks in the affected populations. The short-term and long-term health impact differ between measles, meningococcal A and yellow fever vaccination and by countries based on the local epidemiological situation. Thereby, catch-up vaccination should be planned by considering the heterogeneity in population susceptibility across different countries to measles, meningococcal A and yellow fever outbreaks and implemented in time to prevent these outbreaks. The study findings can inform risk-benefit trade-off discussions around the timing of campaigns.

show abstract

Section: Discussionmentioning

confidence: 99%

“…For the 200 runs, we selected pairs of values for these two parameters so that duration of protection for the older age group is not shorter than the duration of protection for 0-4-year-olds. 14,15 Vaccine efficacy against carriage and disease is 90%.…”

Section: Supplementary Appendixmentioning

confidence: 99%

Impact of COVID-19-related disruptions to measles, meningococcal A, and yellow fever vaccination in 10 countries

Gaythorpe

Abbas

Huber

et al. 2021

Preprint

Self Cite

View full text Add to dashboard Cite

show abstract

“…11 Although physical distancing measures due to the COVID-19 pandemic might have reduced the transmission of childhood infectious diseases, the risk of vaccine-preventable disease outbreaks among children will increase as COVID-19-related mitigation measures are lifted. 12 Therefore, we commend Causey and colleagues 1 for generating this timely evidence and these modelled estimates of disruptions to childhood immunisation as a result of the COVID-19 pandemic, which are important for inferring immunity gaps and epidemiological risk assessment of vaccine-preventable disease outbreaks among children in the future. We recommend national immunisation programmes to act upon this valuable evidence for planning and implementation of catch-up vaccination services to close the immunity gaps, to avoid reversing the substantial gains from childhood immunisation in reducing mortality and morbidity globally.…”

Section: Disruptions To Childhood Immunisation Due To the Covid-19 Pandemicmentioning

confidence: 99%

Disruptions to childhood immunisation due to the COVID-19 pandemic

Abbas

Mogasale

2021

The Lancet

View full text Add to dashboard Cite

“…A recent study has examined risks of vaccine-preventable disease outbreaks (measles, meningococcal A, and Yellow Fever) associated with delaying immunisation campaigns, which varied across countries 11 . Another study assessed the risk of measles outbreaks in Kenya and found that although COVID-19 interventions also temporarily reduced the risk of an outbreak from measles immunity gaps, this risk rises rapidly once these restrictions are lifted highlighting the need to implement catch-up campaigns 12 . One study looked at the risk of transmission in the community during fixed-post or house-to-house immunisation campaigns in six countries (Angola, Ecuador, Pakistan, Ukraine, Nepal and Lao PDR), but did not model specific interactions between vaccination staff and service users 13 .…”

Section: Introductionmentioning

confidence: 99%

SARS-CoV-2 infection risk during delivery of childhood vaccination campaigns: a modelling study

Procter

Abbas

Griffiths

et al. 2021

Preprint

Self Cite

View full text Add to dashboard Cite

Background The COVID-19 pandemic has disrupted delivery of immunisation services globally. Many countries have postponed vaccination campaigns out of concern about infection risks to staff delivering vaccination, the children being vaccinated and their families. The World Health Organization recommends considering both the benefit of preventive campaigns and the risk of SARS-CoV-2 transmission when making decisions about campaigns during COVID-19 outbreaks, but there has been little quantification of the risks. Methods We modelled excess SARS-CoV-2 infection risk to vaccinators, vaccinees and their caregivers resulting from vaccination campaigns delivered during a COVID-19 epidemic. Our model used population age-structure and contact patterns from three exemplar countries (Burkina Faso, Ethiopia, and Chile). It combined an existing compartmental transmission model of an underlying COVID-19 epidemic with a Reed-Frost model of SARS-CoV-2 infection risk to vaccinators and vaccinees. We explored how excess risk depends on key parameters governing SARS-CoV-2 transmissibility, and aspects of campaign delivery such as campaign duration, number of vaccinations, and effectiveness of personal protective equipment (PPE) and symptomatic screening. Results Infection risks differ considerably depending on the circumstances in which vaccination campaigns are conducted. A campaign conducted at the peak of a SARS-CoV-2 epidemic with high prevalence and without special infection mitigation measures could increase absolute infection risk by 32% to 58% for vaccinators, and 0.3% to 0.9% for vaccinees and caregivers. However, these risks could be reduced to 3.6% to 8.0% and 0.1% to 0.4% respectively by use of PPE that reduces transmission by 90% (as might be achieved with N95 respirators or high-quality surgical masks) and symptomatic screening. Conclusions SARS-CoV-2 infection risks to vaccinators, vaccinees and caregivers during vaccination campaigns can be greatly reduced by adequate PPE, symptomatic screening, and appropriate campaign timing. Our results support the use of adequate risk mitigation measures for vaccination campaigns held during SARS-CoV-2 epidemics, rather than cancelling them entirely.

show abstract

The importance of supplementary immunisation activities to prevent measles outbreaks during the COVID-19 pandemic in Kenya

Cited by 5 publications

References 22 publications

Impact of COVID-19-related disruptions to measles, meningococcal A, and yellow fever vaccination in 10 countries

Impact of COVID-19-related disruptions to measles, meningococcal A, and yellow fever vaccination in 10 countries

Disruptions to childhood immunisation due to the COVID-19 pandemic

SARS-CoV-2 infection risk during delivery of childhood vaccination campaigns: a modelling study

Contact Info

Product

Resources

About