Title:
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A cluster-randomised non-inferiority trial of the impact of a two-dose compared to three-dose schedule of pneumococcal conjugate vaccination in rural Gambia: the PVS trial |
Abstract:
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BACKGROUND: Pneumococcal conjugate vaccines (PCV) effectively prevent pneumococcal disease but the global impact of pneumococcal vaccination is hampered by the cost of PCV. The relevance and feasibility of trials of reduced dose schedules is greatest in middle- and low-income countries such as The Gambia where PCV has been introduced with good disease control but where transmission of vaccine-type pneumococci persists. We are conducting a large cluster-randomised non-inferiority field trial of an alternative reduced dose schedule of PCV compared to the standard schedule the PVS trial. METHODS: PVS is a prospective cluster-randomised non-inferiority real-world field trial of an alternative schedule of one dose of PCV scheduled at age 6 weeks with a booster dose at age 9 months (i.e. the alternative 1 + 1 schedule) compared to the standard schedule of three primary doses scheduled at 6 10 and 14 weeks of age (i.e. the standard 3 + 0 schedule). The intervention will be delivered for 4 years. The primary endpoint is the population-level prevalence of nasopharyngeal vaccine-type pneumococcal carriage in children aged 2 weeks to 59 months with clinical pneumonia in year 4 of the trial. Participants and field staff are not masked to group allocation while measurement of the laboratory endpoint will be masked. Sixty-eight geographic population clusters have been randomly allocated in a 1:1 ratio to each schedule and all resident infants are eligible for enrolment. All resident children less than 5 years of age are under continuous surveillance for clinical safety endpoints measured at 11 health facilities; invasive pneumococcal disease radiological pneumonia clinical pneumonia and hospitalisations. Secondary endpoints include the population-level prevalence of nasopharyngeal vaccine-type pneumococcal carriage in years 2 and 4 and vaccine-type carriage prevalence in unimmunised infants aged 612 weeks in year 4. The trial includes components of mathematical modelling health economics and health systems research. DISCUSSION: Analysis will account for potential non-independence of measurements by cluster comparing the population-level impact of the two schedules with interpretation at the individual level. The non-inferiority margin is informed by the acceptable loss of effect of the alternative compared to the standard schedule. The secondary endpoints will provide substantial evidence to support the interpretation of the primary endpoint. PVS will evaluate the effect of transition from a standard 3+ 0 schedule to an alternative 1 + 1 schedule in a setting of high pneumococcal transmission. The results of PVS will inform global decision-making concerning the use of reduced-dose PCV schedules. TRIAL REGISTRATION: International Standard Randomised Controlled Trial Number 15056916. Registered on 15 November 2018. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s13063-021-05964-5. |
Published:
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2022-01-24 |
Journal:
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Trials |
DOI:
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10.1186/s13063-021-05964-5 |
DOI_URL:
|
http://doi.org/10.1186/s13063-021-05964-5 |
Author Name:
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Mackenzie Grant A |
Author link:
|
https://covid19-data.nist.gov/pid/rest/local/author/mackenzie_grant_a |
Author Name:
|
Osei Isaac |
Author link:
|
https://covid19-data.nist.gov/pid/rest/local/author/osei_isaac |
Author Name:
|
Salaudeen Rasheed |
Author link:
|
https://covid19-data.nist.gov/pid/rest/local/author/salaudeen_rasheed |
Author Name:
|
Hossain Ilias |
Author link:
|
https://covid19-data.nist.gov/pid/rest/local/author/hossain_ilias |
Author Name:
|
Young Benjamin |
Author link:
|
https://covid19-data.nist.gov/pid/rest/local/author/young_benjamin |
Author Name:
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Secka Ousman |
Author link:
|
https://covid19-data.nist.gov/pid/rest/local/author/secka_ousman |
Author Name:
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DAlessandro Umberto |
Author link:
|
https://covid19-data.nist.gov/pid/rest/local/author/dalessandro_umberto |
Author Name:
|
Palmu Arto A |
Author link:
|
https://covid19-data.nist.gov/pid/rest/local/author/palmu_arto_a |
Author Name:
|
Jokinen Jukka |
Author link:
|
https://covid19-data.nist.gov/pid/rest/local/author/jokinen_jukka |
Author Name:
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Hinds Jason |
Author link:
|
https://covid19-data.nist.gov/pid/rest/local/author/hinds_jason |
Author Name:
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Flasche Stefan |
Author link:
|
https://covid19-data.nist.gov/pid/rest/local/author/flasche_stefan |
Author Name:
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Mulholland Kim |
Author link:
|
https://covid19-data.nist.gov/pid/rest/local/author/mulholland_kim |
Author Name:
|
Nguyen Cattram |
Author link:
|
https://covid19-data.nist.gov/pid/rest/local/author/nguyen_cattram |
Author Name:
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Greenwood Brian |
Author link:
|
https://covid19-data.nist.gov/pid/rest/local/author/greenwood_brian |
sha:
|
538e7ba2c7a8ef02d9b35ef8ee49752ab40a064c |
license:
|
cc-by |
license_url:
|
https://creativecommons.org/licenses/by/4.0/ |
source_x:
|
PMC |
source_x_url:
|
https://www.ncbi.nlm.nih.gov/pubmed/ |
pubmed_id:
|
35073989 |
pubmed_id_url:
|
https://www.ncbi.nlm.nih.gov/pubmed/35073989 |
pmcid:
|
PMC8785014 |
pmcid_url:
|
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8785014 |
url:
|
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8785014/ |
has_full_text:
|
TRUE |
Keywords Extracted from Text Content:
|
infants
nasopharyngeal vaccinetype
PVS
reduced-dose
nasopharyngeal vaccine-type
children
PHP\ASP.Net
9-valent
99,113
specimens
human papillomavirus vaccine
FWHDSS
centre
Harmonised Guideline
GG/MRC
alpha
Human papilloma virus vaccine
Vaccinators
O 2
peripheral
Synflorix®
GG/
oral polio vaccine
COVID-19
lower-chest wall
h.
St George's
Non-typeable isolates
free-call
Measles-Mumps-Rubella [35]
PCV13 vaccines
PCV13-severe
Fig. 4
SUSAR
UK
1 + 1 clusters infants
1, 2, 3
Vaccine
Fuladu West Health
alpha=
Epidemiologist
Waroux
hepatitis B
E6(R2
MSSQL backend database
PCV7/13
Plasma
nasopharyngeal
Front-end
×
Fig. 3
Children
upper
serotypes
V
EC
blood
individuals
peripheral arterial
serotype 1
S. pneumoniae
SAEs
non-vaccine type
ISCTRN
polio vaccine
3-5-year-olds
AVPU
Gambisara
SCC
Measles-Mumps-Rubella-Varicella [36] vaccines
blood cultures
Upper
c
NP carriage of VT
mother
Patients
NVT pneumococcal
CRF
father
thumbprints
measles vaccine
PCV13 [18
Serum
NP specimen
rotavirus
SUSARs
Bank 'low-income'
DMC
Blood
SUSARS
SADRs
Tostan
measlesrubella
micrococcus
OPV
measles
serotypes 1
PCV13
BCG
PI
bile
NVT serotypes
NP VT
trial/future
polio
1 + 1
IPD
PCV9
18C
min-and
PCV13 vaccine
patient
19F
lumbar puncture
1+ 1
NP specimens
Gambia Medicines Control Agency
−
EPI
μl/ml
pleural fluid
Gambia Government/MRCG Joint Ethics Committee
Head
178,510 (225 villages
Fatoto
1 + 1 versus 3 + 0
2 + 1
≥85
trialist
patients
3 + 0 clusters was 6
2+ 1
3+ 0
gentamicin
infants
Koina
PCV10 vaccine
GSK vaccine
March-7
PCV13 vaccine serotypes
children
≤1.38
human
1 + 1alternative
Gambia.
Infants
ethylhydrocupreine
Gambia Government/MRC Joint Ethics Committee
SADR
3 + 0
e-CRF
eCRFs
herd
BHDSS
participants
§
Basse.
4-6
PCV7
NVT pneumococci
Oct-Dec
haemoglobin
plasma
PCV10
vaccine
colonies
Janjanbureh
SGUL
pneumococci
Streptococcus viridans
Jan-Sept
b) non-PCV13 vaccine serotypes
− 5
NP swab
joint
latex
lung aspirate
IgG
Gambia
rotavirus vaccine
pleural
of~1500
NP
NP swabs
head,
ICC=
NP carriage of
ID
7F, 9 V
PVS
≤15
peripheral O 2
https://doi
Bill
GM
EC
Joint Global Health Trials Scheme
Statistician
SF
IH
EPI
UD
AP
UK
INV006724
patients
infants
BG
org/10.1186/s13063-021
IO
CN, |
Extracted Text Content in Record:
|
First 5000 Characters:Background: Pneumococcal conjugate vaccines (PCV) effectively prevent pneumococcal disease but the global impact of pneumococcal vaccination is hampered by the cost of PCV. The relevance and feasibility of trials of reduced dose schedules is greatest in middle-and low-income countries, such as The Gambia, where PCV has been introduced with good disease control but where transmission of vaccine-type pneumococci persists. We are conducting a large cluster-randomised, non-inferiority, field trial of an alternative reduced dose schedule of PCV compared to the standard schedule, the PVS trial. Methods: PVS is a prospective, cluster-randomised, non-inferiority, real-world field trial of an alternative schedule of one dose of PCV scheduled at age 6 weeks with a booster dose at age 9 months (i.e. the alternative '1 + 1' schedule) compared to the standard schedule of three primary doses scheduled at 6, 10, and 14 weeks of age (i.e. the standard '3 + 0' schedule). The intervention will be delivered for 4 years. The primary endpoint is the population-level prevalence of nasopharyngeal vaccine-type pneumococcal carriage in children aged 2 weeks to 59 months with clinical pneumonia in year 4 of the trial. Participants and field staff are not masked to group allocation while measurement of the laboratory endpoint will be masked. Sixty-eight geographic population clusters have been randomly allocated, in a 1:1 ratio, to each schedule and all resident infants are eligible for enrolment. All resident children less than 5 years of age are under continuous surveillance for clinical safety endpoints measured at 11 health facilities; invasive pneumococcal disease, radiological pneumonia, clinical pneumonia, and hospitalisations. Secondary endpoints include the population-level prevalence of nasopharyngeal vaccinetype pneumococcal carriage in years 2 and 4 and vaccine-type carriage prevalence in unimmunised infants aged 6-12 weeks in year 4. The trial includes components of mathematical modelling, health economics, and health systems research.
Discussion: Analysis will account for potential non-independence of measurements by cluster, comparing the populationlevel impact of the two schedules with interpretation at the individual level. The non-inferiority margin is informed by the 'acceptable loss of effect' of the alternative compared to the standard schedule. The secondary endpoints will provide substantial evidence to support the interpretation of the primary endpoint. PVS will evaluate the effect of transition from a standard 3+ 0 schedule to an alternative 1 + 1 schedule in a setting of high pneumococcal transmission. The results of PVS will inform global decision-making concerning the use of reduced-dose PCV schedules. Trial registration: International Standard Randomised
Despite the pneumococcus causing more childhood deaths than any single pathogen [2, 3] , global control of pneumococcal disease is hampered by the cost of pneumococcal conjugate vaccines (PCVs). In addition to the relatively high cost of several new vaccines that have recently been introduced in many low-income countries, expanded programmes on immunisation (EPI) face the additional challenge of schedules with increasing numbers of doses. Reducing the cost and complexity of EPI schedules would improve the flexibility, acceptability and sustainability of immunisation programmes.
Low-income countries receive subsidised PCV through the GAVI Alliance, providing a co-payment of 0.15-0.30 USD per dose (increasing 15% per year in 'intermediate' countries) [4] . However, when countries' Gross National Income per capita exceeds the World Bank 'low-income' threshold of~1500 USD, they begin to transition from GAVI support. During transition, co-payments increase each year for 5 years to a final price set under the GAVI Advance Market Commitment (2.00-2.90 USD per dose) [5] . GAVI expenditure on PCV represents approximately half of its vaccine budget [6] . The importance of the cost of PCV was evident in The Gambia where its introduction, at 0.2 USD per dose, increased the national cost of the EPI programme by one third, with vaccine representing 91% of the total cost of introducing PCV [7] . Thus, a major determinant of the sustainability of pneumococcal vaccination in low-and middle-income countries is vaccine cost. Middle-income countries, ineligible for GAVI support, experience many child deaths due to pneumococcus but cost has precluded many from introducing PCV.
EPI programmes in low-and middle-income countries are becoming more complicated and costly with the introduction of new vaccines. The addition of vaccines such as PCV, rotavirus vaccine, injectable polio vaccine, meningococcal group A conjugate, human papillomavirus vaccine, and typhoid conjugate challenges the implementation, acceptance, cold-chain capacity, and sustainability of EPIs. The difficulty of introducing such new vaccines has its biggest impact in low-and middle-income countries where the bu |
Keywords Extracted from PMC Text:
|
NP
BHDSS
polio
NVT pneumococcal
PCV10 vaccine
2–12
lumbar puncture
CRF
OPV
Synflorix®
NP swabs
19F
×
thumbprints
Epidemiologist
Head
PCV13—
CO2
PCV13
gentamicin
PCV13 [18
Measles-Mumps-Rubella [35]
human papillomavirus vaccine
haemoglobin
DMC
ethylhydrocupreine
2+ 1
pneumococci
eCRFs
NP carriage of
COVID-19
Bank '
Front-end
serotype 1
human
trialist
oral polio vaccine
Koina
1 + 1
patients
Blood
ageAge
PCV13 vaccine serotypes
PCV9
Non-typeable isolates
Measles-Mumps-Rubella-Varicella [36] vaccines
BCG
Waroux
individuals
NP VT
mother's
Sabi
Gambia Government/MRCG Joint Ethics Committee
NP swab
http://www.equator-network.org/reporting-guidelines/spirit-2013-statement-defining-standard-protocol-items-for-clinical-trials/
≤15
pleural fluid
colonies
Fatoto
SADRs
EPI '
Patients
EC's
GSK vaccine
measles vaccine
PCV13 vaccines
−
serotypes
Gambia Medicines Control Agency
's
7F, 9 V
children
patient
infants
Human papilloma virus vaccine
PVS
≥85
PCV7
Vaccine
Streptococcus viridans
Gambisara
latex
Fig. 4
IgG
NVT pneumococci
NVT serotypes
EC
2016/2017
3–5-year-olds
blood cultures
participants
upper
PCV10
e-CRF
O2
alpha
UK
3+ 0
2 + 1
guardians
SAEs
blood
Gambia.
Bansang
RHDs
ISCTRN
Plasma
Children
SADR
ID
FWHDSS
lower-chest wall
free-call
serotypes 1
SUSARS
S. pneumoniae
1 + 1 clusters infants
plasma
PCVs
's father
NP specimen
herd
St George's
9-valent
hepatitis B
curly brackets
peripheral arterial
b) non-PCV13 vaccine serotypes
URR
1, 2, 3
language
SCC
SGUL
low-
μl/ml
rotavirus vaccine
PCV7/13
1+ 1
GG/MRC
lung aspirate
EPI
polio vaccine
nasopharyngeal
Oct–Dec 2015
Basse.
3 + 0
≤1.38
Gambia
head,
peripheral O2
rotavirus
Vaccinators
− 28–91
Harmonised Guideline
micrococcus
c
Janjanbureh
IPD
Tostan
SUSAR
18C
DMC's
h.
MSSQL backend database
Serum
measles
PCV13 vaccine
NP specimens
SUSARs
PI
Infants
Gambia Government/MRC Joint Ethics Committee
E6(R2
specimens
1 + 1 versus 3 + 0
PHP\ASP.Net
joint
bile
vaccine
3 + 0 clusters was 6 |
Extracted PMC Text Content in Record:
|
First 5000 Characters:Note: the numbers in curly brackets in this protocol refer to SPIRIT checklist item numbers [1]. The order of the items has been modified to group similar items (see http://www.equator-network.org/reporting-guidelines/spirit-2013-statement-defining-standard-protocol-items-for-clinical-trials/).
Despite the pneumococcus causing more childhood deaths than any single pathogen [2, 3], global control of pneumococcal disease is hampered by the cost of pneumococcal conjugate vaccines (PCVs). In addition to the relatively high cost of several new vaccines that have recently been introduced in many low-income countries, expanded programmes on immunisation (EPI) face the additional challenge of schedules with increasing numbers of doses. Reducing the cost and complexity of EPI schedules would improve the flexibility, acceptability and sustainability of immunisation programmes.
Low-income countries receive subsidised PCV through the GAVI Alliance, providing a co-payment of 0.15–0.30 USD per dose (increasing 15% per year in 'intermediate' countries) [4]. However, when countries' Gross National Income per capita exceeds the World Bank 'low-income' threshold of ~ 1500 USD, they begin to transition from GAVI support. During transition, co-payments increase each year for 5 years to a final price set under the GAVI Advance Market Commitment (2.00–2.90 USD per dose) [5]. GAVI expenditure on PCV represents approximately half of its vaccine budget [6]. The importance of the cost of PCV was evident in The Gambia where its introduction, at 0.2 USD per dose, increased the national cost of the EPI programme by one third, with vaccine representing 91% of the total cost of introducing PCV [7]. Thus, a major determinant of the sustainability of pneumococcal vaccination in low- and middle-income countries is vaccine cost. Middle-income countries, ineligible for GAVI support, experience many child deaths due to pneumococcus but cost has precluded many from introducing PCV.
EPI programmes in low- and middle-income countries are becoming more complicated and costly with the introduction of new vaccines. The addition of vaccines such as PCV, rotavirus vaccine, injectable polio vaccine, meningococcal group A conjugate, human papillomavirus vaccine, and typhoid conjugate challenges the implementation, acceptance, cold-chain capacity, and sustainability of EPIs. The difficulty of introducing such new vaccines has its biggest impact in low- and middle-income countries where the burden of disease is greatest but resources are scarce.
The Medical Research Council Unit The Gambia at London School of Hygiene & Tropical Medicine (MRCG at LSHTM) has a long history investigating the burden of pneumococcal disease and pneumococcal vaccination. In 2000–2004, a trial of a 9-valent PCV (PCV9) was conducted in Central and Upper River Regions (CRR and URR) of The Gambia. Vaccine efficacy in children aged 3–29 months was 37% against radiological pneumonia, 77% against vaccine-type (VT) invasive pneumococcal disease (IPD), and 16% against all-cause mortality [8]. In 2009, The Gambia introduced PCV7 into the routine EPI using a three-dose schedule without a booster dose (i.e. a '3 + 0' schedule). In 2011, PCV7 was replaced by PCV13. The Pneumococcal Surveillance Project (PSP) has documented the impact of PCV13 in the Basse Health & Demographic Surveillance System (BHDSS) in rural Gambia. Four to five years after the introduction of PCV7/13 the incidence of VT IPD had declined by 82%, with a 24% reduction in radiological pneumonia, and 61% reduction in severe hypoxic pneumonia in children aged 2–59 months [9, 10]. Eight years after the introduction of PCV7/13 the incidence of VT IPD in the 2–59 month age group has declined by 92% and radiological pneumonia has declined by 33% [11]. Before the introduction of PCV, PSP detected an average of 35 annual cases of VT IPD among children aged 2–59 months. In 2016, we detected six cases of VT IPD, and in 2017, we detected three. In 2016/2017, we detected zero cases of VT IPD among children in the first year of life. These data indicate that the introduction of PCV7/13 has now controlled VT IPD.
It is now evident that following the introduction of PCV13, herd protection has developed in The Gambia. The annual count of VT IPD in older children in PSP was six to ten before the introduction of PCV13 in 2011. Following the introduction of PCV13 the annual case counts in 2015, 2016, and 2017 were four, one, and zero, respectively. In the 5–14 year age group, IPD incidence declined by 69% (95%CI, − 28–91%) and radiological pneumonia by 27% (95%CI, − 5–49%) [11]. Similar findings of the direct and herd effect of PCV are evident in Kenya [12, 13].
The prevalence of nasopharyngeal (NP) carriage of PCV13 VT in the BHDSS area before the introduction of vaccine was 47% in the under-5-year age group. In 2015 and 2017, the prevalence of vaccine types was 15% and 17%, respectively (author's own data). The downward trajectory of VT p |
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