Introduction of Sequential Inactivated Polio Vaccine–Oral Polio Vaccine Schedule for Routine Infant Immunization in Brazil's National Immunization Program
Introduction of Sequential Inactivated Polio Vaccine-Oral Polio Vaccine Schedule for Routine Infant Immunization in Brazil's National Immunization Program
Carla Magda Allan S. Domingues 1 2
Sirlene de Fátima Pereira 2
Ana Carolina Cunha Marreiros 2
Nair Menezes 2
Brendan Flannery 0
0 Global Immunization Division, Center for Global Health, Centers for Disease Control and Prevention , Atlanta , Georgia
1 Center for Tropical Medicine, University of Brasília , Distrito Federal , Brazil
2 Secretariat of Health Surveillance, Brazilian Ministry of Health
In August 2012, the Brazilian Ministry of Health introduced inactivated polio vaccine (IPV) as part of sequential polio vaccination schedule for all infants beginning their primary vaccination series. The revised childhood immunization schedule included 2 doses of IPV at 2 and 4 months of age followed by 2 doses of oral polio vaccine (OPV) at 6 and 15 months of age. One annual national polio immunization day was maintained to provide OPV to all children aged 6 to 59 months. The decision to introduce IPV was based on preventing rare cases of vaccineassociated paralytic polio, financially sustaining IPV introduction, ensuring equitable access to IPV, and preparing for future OPV cessation following global eradication. Introducing IPV during a national multivaccination campaign led to rapid uptake, despite challenges with local vaccine supply due to high wastage rates. Continuous monitoring is required to achieve high coverage with the sequential polio vaccine schedule.
acute flaccid paralysis; Brazil; inactivated polio vaccine; poliomyelitis; vaccination schedule
The World Health Organization (WHO) recommends
that all children worldwide be immunized against polio
and that all countries achieve and maintain high levels of
coverage with polio vaccine . Until global polio
eradication is achieved, WHO and the Pan American Health
Organization (PAHO) guidance for national policy on
polio immunization is based on evaluation of the
potential for wild poliovirus (WPV) importation and
transmission [1, 2]. Important factors include risk of WPV
importations resulting from international travel, polio
vaccination coverage, quality of surveillance for acute
flaccid paralysis (AFP), sanitation, and socioeconomic
conditions . In the pre-eradication period, WHO
recommends inactivated polio vaccine (IPV) as an
alternative to oral polio vaccine (OPV) only in countries that
have the lowest risk of both WPV importation and
transmission . In countries that do not achieve
homogeneous vaccination coverage of 95% or greater in every
district, PAHO recommends conducting annual polio
vaccination campaigns targeting all children <5 years of
age regardless of prior vaccination status .
Brazil is an upper-middle-income country in South
America with a population of 199 million and
approximately 3 million annual births. Since its creation in
1973, Brazil’s National Immunization Program has
exclusively used OPV for routine infant immunizations
and supplemental immunization activities (SIAs) .
Use of OPV successfully interrupted transmission of
wild poliovirus in Brazil and eliminated polio from the
Americas. Brazil has maintained high polio vaccination
coverage nationwide since polio elimination, although
heterogeneous vaccination coverage may leave pockets
of individuals susceptible to WPV infection in the
event of a WPV importation.
In August 2012, the Brazilian Ministry of Health
introduced inactivated polio vaccine (IPV) as part of
sequential IPV-OPV vaccination, including 2 doses of IPV at 2
and 4 months of age followed by 2 doses of trivalent OPV at 6
and 15 months of age for all infants beginning their primary
vaccination series . A sequential IPV-OPV schedule was chosen
to prevent vaccine-associated paralytic poliomyelitis (VAPP) and
provide mucosal immunity to reduce the potential for
transmission of wild or vaccine-derived polioviruses (VDPVs). With the
introduction of the sequential IPV-OPV schedule, the Ministry
of Health revised the strategy for National Polio Immunization
Days to conduct a single round of polio vaccination, during the
month of June, offering OPV to all children aged 6 to 59 months
regardless of prior polio vaccination status . The introduction
of a sequential IPV-OPV schedule and transition to a single
supplemental polio immunization day were seen as preparatory steps
for a posteradication polio vaccination strategy in Brazil. Here we
review considerations for IPV introduction in Brazil’s National
Immunization Program and describe early uptake of IPV.
BRIEF HISTORY OF POLIO VACCINATION IN
Polio vaccination with OPV began in the early 1960s in response
to polio outbreaks . OPV was one of the recommended
routine childhood vaccines when the National Immunization
Program was created in 1973 (Table 1), although coverage with
3 doses of OPV among children aged <1 year reached only 51%
in 1979 . From 1971 to 1973, nationally coordinated mass
vaccination campaigns were conducted in most states and
resulted in dramatic declines in polio incidence .
Discontinuation of mass campaigns in 1974 led to resurgence in polio
cases, which peaked in 1979 and resulted in institution of
biannual national polio immunization days (NIDs) in 1980 [5–7].
The objective of polio NIDs was to vaccinate all children aged
<5 years with OPV, regardless of prior vaccination history.
NIDs played an important role in polio elimination in Brazil
and the Americas . The last confirmed case of wild
poliovirus in Brazil occurred in 1989, followed by the last case in the
Americas in 1991. WHO certified polio elimination from Brazil
and the Americas in 1994 [8, 9].
Investigations of polio outbreaks in Brazil and serologic
studies helped identify factors that influenced immunogenicity
of OPV and led to changes in the OPV formulation adopted
for the Global Polio Eradication Initiative [10–13]. In addition,
research in Brazil on IPV in the 1980s identified potential
advantages of IPV for routine immunization, including higher
seroconversion rates and prevention of VAPP, while OPV was
preferable for mass vaccination .
CONSIDERATIONS FOR IPV INTRODUCTION
Prior to IPV introduction into Brazil’s childhood
immunization schedule, revision of the national polio vaccination policy
Table 1. Selected Revisions of Recommended Childhood
Immunization Schedule in Brazil’s National Immunization
Creation of National Immunization Program
(recommended immunizations: BCG, OPV, measles,
Polio Elimination Plan—2 national polio immunization
Sustainability and National Self-Sufficiency Initiative
(production of DTwP by national vaccine
HepB vaccine campaigns in high-risk areas
Established goals for 90% routine vaccination
coverage (OPV, DTwP) and 95% coverage for OPV
campaigns and measles vaccination
Multivaccination in National Immunization Days (all
Measles elimination plan (measles 2nd dose)
Universal infant immunization against HepB
Phased introduction of MMR vaccine
Yellow fever vaccination in high-risk areas incorporated
into National Immunization Program
Rubella control strategy (measles-rubella or MMR
campaigns, targeting persons aged 1–11 y in most
Introduction of Hib conjugate vaccine
Quadrivalent DTwP-Hib replaces DTwP and
monovalent Hib conjugate vaccine
Introduction of oral rotavirus vaccine (Human
Introduction of pneumococcal conjugate vaccine
Introduction of MenC conjugate vaccine
Sequential IPV-OPV vaccination schedule for polio
Pentavalent DTwP-Hib-HepB replaces DTwP-Hib and
HepB vaccines for infant vaccination
Abbreviations: BCG, Bacillus Calmette–Guérin; HepB, hepatitis B; Hib,
Haemophilus influenzae type b; DTwP, diphtheria-tetanus-pertussis (whole
cell); IPV, inactivated polio vaccine; MenC, meningococcal serogroup C; MMR,
measles-mumps-rubella; OPV, oral polio vaccine.
was discussed at multiple meetings of the national technical
advisory committee on immunizations, composed of
immunization experts and representatives of professional societies.
Considerations included risk of WPV importation, vaccine
safety, sustainability, equity, vaccination strategies, and optimal
schedule. In 2008, the National Immunization Program began
developing a plan for IPV introduction through routine
immunization services. The main components of the revised
polio vaccination policy included use of a sequential IPV-OPV
schedule, continuation of polio vaccination strategies (NIDs
and routine vaccination) until global polio eradication, and
sustainability of polio vaccination in the recommended childhood
Potential for WPV Importation and Transmission
As long as wild poliovirus circulates anywhere in the world, all
polio-free countries are at risk for WPV importation ;
countries immediately bordering endemic countries and those with
low routine immunization coverage are at highest risk .
Transmission potential following an importation is also higher
in tropical countries with suboptimal sanitation . Brazil has
not had any WPV importations since certification of
elimination, and all reported cases of paralytic poliomyelitis in the
Americas have been caused by vaccine viruses or VDPVs .
However, importations of WPV into polio-free countries have
occurred as a result of international air travel , and
previously polio-free regions have experienced extensive outbreaks
resulting from WPV importation .
Routine coverage with 3 doses of OPV (OPV3) in Brazilian
infants, based on administrative data, has been maintained above
95% nationally since 2000 (Table 2). Due to the limitations of
administrative data to monitor immunization coverage at the
municipal level, state and municipal immunization programs
increasingly use rapid coverage monitoring (used in large scale
following mass measles-rubella vaccination in 2008 ) to
identify undervaccinated populations. A survey of children in
state capital cities showed high OPV3 coverage at all
socioeconomic levels . In addition, introduction of a national
immunization registry in 2012 will eventually provide more
accurate estimates of vaccination coverage and reduce the
reliance on administrative data .
Between 1970 and 2010, indicators of sanitation
infrastructure and socioeconomic conditions improved dramatically in
Brazil . However, sanitation, development, and
immunization coverage are heterogeneously distributed throughout
Brazil, and a large number of municipalities report less than
95% coverage with OPV3, especially in tropical areas (Figure 1).
In these areas, continued OPV use in routine immunizations
and SIAs provides advantages for boosting mucosal
immunity, facilitating administration in remote areas, and
providing herd immunity through secondary spread of vaccine
Prevention of VAPP
Prevention of VAPP and risk of VDPVs in
immunocompromised children, despite their rare occurrence, was considered
important for maintaining public confidence in the national
immunization program. Reported incidence of VAPP in Brazil
of 1 case per 10.7–13 million OPV doses administered (or 1
case per 2.4–5.1 million first OPV doses) [22, 23] was lower
than estimates from the United States (2.5 cases per million
OPV doses administered or 0.7 cases per million first OPV
doses) , raising concerns about completeness of VAPP
ascertainment in Brazil.
Limitations of Surveillance
In Brazil, AFP surveillance is conducted by state and municipal
health departments and coordinated by the Secretariat for
Doses Administered (% Pop <1 y)
Doses Administered (% Pop <5 y) 2002 2003
3 212 618 (105.0)
3 209 756 (105.6)
3 152 042 (104.3)
3 188 216 (105.1)
3 086 120 (104.8)
3 032 286 (104.9)
2 920 562 (99.5)
2 962 167 (102.8)
2 838 743 (98.6)
2 891 340 (100.4)
2 781 341 (96.6)
16 828 472 (100.7)
16 792 599 (99.9)
16 489 247 (97.3)
16 397 934 (94.5)
16 126 323 (94.9)
16 079 786 (100.8)
15 522 157 (99.2)
15 028 995 (97.3)
14 295 965 (92.4)
14 186 318 (100.2)
14 004 200 (98.9)
National Polio Immunization Days 1st Round 2nd Round No. Municipalities
(% Pop <5 y)
16 706 362 (99.9)
16 679 283 (99.2)
16 489 380 (97.3)
16 540 230 (95.3)
16 289 363 (95.9)
15 941 552 (99.9)
14 883 257 (95.1)
15 116 210 (97.9)
14 743 488 (95.3)
14 102 506 (99.7)
Abbreviations: OVP, oral polio vaccine; OPV3, 3 doses of OPV; Pop, population.
a Based on the number of doses administered divided by the target population. Data for 2012 include doses of inactivated polio vaccine registered as the third dose
of a polio vaccination series.
b Based on the number of OPV doses administered in the municipality during National Polio Immunization Days divided by the municipal population aged <5 years.
Health Surveillance of the Ministry of Health. While the main
objective of AFP surveillance is early detection of WPV
importation, it is also essential for detection of vaccine-associated
cases and VDPVs. All cases of AFP in individuals younger than
15 years, as well as any suspected poliomyelitis case in
individuals of any age with travel history in the previous 30 days to
countries with circulation of WPV, must be reported to state
and municipal health departments, investigated immediately,
and entered into the national surveillance system for notifiable
diseases [Sistema de Informação de Agravos de Notificação
(Sinan)]. Follow up includes examination of neurological
function and laboratory examination of stool specimens (ideally
collected within 14 days of onset of paralysis).
Review of AFP surveillance indicators highlighted the need
for maintaining surveillance quality and timeliness of diagnosis
of AFP cases to rapidly detect and respond to poliovirus
importations . During 2003–2012, the national nonpolio AFP
reporting rate was slightly above 1.0 case per 100 000 population
aged <15 years, PAHO’s target reporting rate for AFP
surveillance in the Americas (Table 3). However, fewer than 80% of
reported cases had collection of adequate stool specimens,
falling below the target indicator. Maintaining surveillance
quality is challenging and requires coordination between health
professionals, surveillance officers, laboratory staff, and
directors of the Unified Health System (SUS) at all levels.
Polio Vaccination Strategies
From 1980 to 2011, Brazil held biannual NIDs (usually in June
and August) for all children under 5 years of age, regardless of
prior immunization status. With the introduction of the
sequential IPV-OPV schedule, the National Immunization Program
maintained 1 annual NID (in June) with OPV, targeting children
aged 6–59 months, regardless of prior immunization status. The
previous NID in August was replaced with a multivaccination
campaign to provide children up to their fifth birthday with
missing vaccinations and to update child health cards.
The decision to replace 1 NID day with a multivaccination
campaign was based on potential benefits of social mobilization
to improve routine immunization coverage and complete
vaccination schedules. In the 1980s, Brazil’s National Immunization
Program encouraged the use of NIDs to provide opportunities
for “catch-up” vaccination of children missing recommended
doses, as long as multivaccination did not have a
negative impact on vaccination against poliomyelitis . The
decision regarding which antigens to offer during NIDs was left
up to state and municipal immunization programs. An
immunization survey of children born in 2005 showed that 15% had
received recommended vaccines needed to complete
immunization schedules during the most recent NID .
Revision of Recommended Childhood Immunization Schedule
IPV introduction was part of a revision of the childhood
immunization calendar in 2012 (Table 4), including the sequential
IPV-OPV schedule and 3 doses of pentavalent
DTwP–Haemophilus influenzae type b conjugate-recombinant hepatitis B
vaccine ( pentavalent vaccine, Bio-Manguinhos Institute, Rio de
Janeiro, Brazil and Butantan Institute, São Paulo, Brazil).
Pentavalent vaccine replaced quadrivalent DTwP-Hib vaccine and
eliminated the need for 2 injections of monovalent hepatitis B
Investigation Within 48 h of Notification
Adequate Stool Specimen
Abbreviation: AFP, acute flaccid paralysis.
a Collection of 2 stool specimens 24 hours apart within 14 days of onset of paralysis.
b Reported AFP cases per 100 000 persons <15 years.
vaccine to complete the primary hepatitis B schedule ( previously
recommended at birth, 1 month, and 6 months of age). The
birth dose of monovalent hepatitis B vaccine was maintained for
the prevention of vertical transmission. Launching the sequential
IPV-OPV schedule with pentavalent vaccine introduction
(replacing separate injections of hepatitis B and DTwP-Hib
vaccines) resulted in the same number of injections a child would
receive to complete the recommended immunization schedule.
An interval of 60 days was recommended between the first
and second IPV doses, as well as between the second IPV dose
and the first OPV dose in the sequential series. During the first
6 months of life, a minimum interval between doses of 30 days
was recommended for infants traveling to endemic countries or
at risk of exposure to WPV. Additional guidance was provided
for vaccination of children who had received OPV or for whom
OPV was not recommended (Table 5).
The additional cost of IPV was compared with introduction of
new vaccines and increases in the National Immunization
Program budget . Equity was an important consideration,
as IPV became recommended by professional societies ,
while children of higher socioeconomic status were more likely
to receive IPV in the private sector  and less likely to receive
Child’s Age and Prior Vaccination Status
At least 2 mo of age, received 1 dose of OPV
between birth and 60 d of life
Age <12 mo, previously unvaccinated against polio
Child with medical indication to receive IPV at CRIEa
Children who begin schedule with OPV may continue with
OPV doses administered from birth to 60 d of life are not
counted for the primary series
Previously unvaccinated children ≥12 mo may initiate polio
vaccination series with OPV
Sequential IPV-OPV schedule not recommended
Source: National Immunization Program, Ministry of Health, Brasília, Brazil.
Abbreviations: IPV, inactivated polio vaccine; OPV, oral polio vaccine; CRIE, Special Immunobiological Reference Center.
a Acronym for name in Portuguese: Centro de Referência para Imunobiologicos Especiais.
OPV during NIDs . In the public sector, IPV had been
recommended for specific groups of children for whom OPV was
contraindicated and was provided at specialized vaccine
reference centers (CRIE, for the acronym in Portuguese) since 1993
. Increased referral of children to specialized reference
centers for IPV resulted in a jump in IPV doses administered
from 20 145 in 2008 to 37 305 in 2010.
In 2010, the Science and Technology Secretariat of the Ministry
of Health, together with public vaccine manufacturer
BioManguinhos Institute, Rio de Janeiro, developed technical
guidelines for incorporating standalone IPV or IPV-containing
combination vaccines into the National Immunization Program,
considering options of international purchase, national
production, or acquisition of technology for national production. These
technical guidelines estimated costs of IPV introduction, as well
as mapping strategies to achieve sustainable IPV use in Brazil.
To comply with national legislation requiring self-sustainability
in vaccine production as well as international regulations on IPV
manufacture, Brazil’s Ministry of Health and Bio-Manguinhos
Institute signed an agreement with Sanofi Pasteur to supply IPV
types 1, 2, and 3 for formulation and distribution in Brazil after
2012. Bio-Manguinhos Institute would also begin evaluating
combination products, including imported IPV and domestically
produced DTwP, hepatitis B (HepB), and H. influenzae type b (Hib)
antigens for future use in Brazil.
EARLY UPTAKE OF IPV
Beginning with the national multivaccination campaign in
August 2012, IPV was administered to children at 2 months of
age (60 days), initiating the primary immunization series with
pentavalent DTwP-Hib-HepB, pneumococcal conjugate
vaccine, and oral rotavirus vaccine. Vaccination histories of
children aged <5 years documented in child health cards were
evaluated by health workers at fixed vaccination posts in health
facilities or mobile posts that functioned during the campaign.
Vaccination series were initiated in previously unvaccinated
children and those without documented vaccination history.
Immunizations offered included all vaccines in the
recommended childhood vaccination calendar of the National Immunization
Program. Vaccination was selective, based on evaluation of each
child’s vaccination history. IPV and pentavalent
DTwP-HibHepB vaccines were administered according to the revised
childhood vaccination schedule.
The 2012 national multivaccination campaign was organized
along the same principles as an NID to expand access to
vaccines by providing immunizations at a large number of fixed
and mobile vaccine posts, as well as through outreach. The
multivaccination campaign was conducted over a 7-day period
from 18 to 24 August and involved approximately 350 000
health workers at 115 000 vaccination posts (including
approximately 30 000 permanent vaccination posts at health facilities)
and 40 000 vehicles. Federal funding for the campaign was the
same as for the national polio immunization day (18.6 million
reais [US $9.3 million]) in addition to contributions from state
and municipal health departments.
Administrative Estimates of IPV Coverage
Brazil has an annual birth cohort of approximately 2.8 million
surviving infants. In 2012, the monthly vaccination target
(based on registered live births in 2011) was 240 006 children
aged <1 year for each vaccine dose recommended in the first year
of life. During the initial multivaccination campaign from 18 to
24 August 2012, a total of 114 803 IPV doses were administered
to children aged <1 year (Table 6); 102 784 were registered as first
doses and 12 019 as second doses for children who received IPV
in the private sector or had medical indications for receipt of IPV
at the Ministry of Health’s CRIE. In routine immunization
services, a total of 770 942 first IPV doses were administered from
September to December 2012, reaching 80% of the quarterly target
of 960 024 doses among children aged <1 year nationally and
>95% of the quarterly target in 2658 (48%) of 5564 municipalities
(Figure 1B), while 319 579 second doses were administered in
No. of IPV Doses Reported
(% of Target)
Calendar Month August
102 784 (43)
173 554 (72)
205 153 (85)
204 333 (85)
187 902 (78)
Abbreviation: IPV, inactivated polio vaccine.
a Monthly target population = 240 006 children aged <1 year (1/12th of
registered live births in 2011 from national live birth registration system
November and December, reaching 67% of the target population
Standalone IPV was included in the children’s immunization
calendar in 2012. A total of 11 million doses of standalone IPV in
10-dose vials were purchased in 2012 at a cost of 55 million reais
(approximately US $26 million in 2012). Although the 10-dose
presentation of IPV includes 2-phenoxyethanol as a preservative,
vials were to be discarded 6 hours after opening. IPV vaccination
occurred simultaneously in all states and the federal district.
During the first months of IPV use, immunization programs
reported substantially increased vaccine wastage due to
requirements to discard opened vials after 6 hours. Unexpectedly high
wastage resulted in IPV stock-outs in some health centers,
requiring constant management and redistribution of available
vaccine to avoid running out of IPV over larger areas. In cases
of IPV stock-outs at health centers, the National Immunization
Program advised rescheduling children to maintain sequential
IPV-OPV schedules rather than returning to an OPV-only
schedule. In November 2012, Brazil’s national regulatory
authority approved a label change, permitting the use of 10-dose
vials for 7 days after opening. The label change reduced IPV
wastage and resolved problems with vaccine supply.
Surveillance for Adverse Events Following Immunization
IPV is well tolerated and has not been associated with severe
adverse events . Based on reported rates of adverse events
following immunization (AEFI), mild, local reactions were
expected in a small proportion of vaccinees, including erythema
at the injection site (<3%), induration (<12%), and tenderness
(<30%). Reporting of systemic reactions (such as fever) and
other AEFIs associated with any of the vaccines coadministered
with IPV, including DTwP-Hib-HepB, oral rotavirus, and
pneumococcal conjugate vaccine, was expected in infants who had
received IPV. Immunization providers were also alerted to the
possibility of hypersensitivity reactions in infants due to the
presence in the IPV formulation of trace amounts of the
antibiotics streptomycin, neomycin, and polymyxin B. Following IPV
introduction, no increase was observed in rates of reported AEFIs,
including fever, convulsions, and hypotonic-hyporesponsive
episodes (data not shown). A single AEFI (classified as a moderate
local reaction) was reported in an infant who received IPV with
no concomitant injections.
Communication strategies for the multivaccination campaign
targeted 2 main audiences: information for healthcare workers,
professional societies, and opinion leaders provided rationale
for the new vaccination schedule; while public messages
encouraged parents to take children younger than 5 years of age
to an immunization post during the campaign to review the
child’s vaccinations, even if the child was considered “up to
date.” Messages emphasized prevention of vaccine-preventable
diseases, as well as the introduction of 2 new vaccines (
pentavalent vaccine and IPV). Prior to IPV introduction, state and
municipal immunization programs conducted trainings for
healthcare professionals on the sequential IPV-OPV schedule;
high acceptance of IPV, and the revised immunization calendar
was reported. As in other vaccination campaigns, the Brazilian
Minister of Health held a press conference prior to the
campaign launch to explain the objectives of the multivaccination
campaign to the media, reaching a broad audience. Social
networks and electronic media were also used as in previous
campaigns to provide information on vaccination activities .
Brazil is one of a growing number of countries that have
introduced IPV in national immunization programs [15, 31]. As of
December 2012, 66 WHO member states included IPV in national
immunization programs, including 7 in the Americas (Bahamas,
Brazil, Canada, Costa Rica, Mexico, United States, and Uruguay)
. In an additional 18 member states (15 of which are in the
Americas), IPV was recommended for children at increased risk
of VAPP, including immunocompromised children . IPV use
is expected to increase as countries implement WHO
recommendations for the polio endgame strategy .
With the introduction of a sequential IPV-OPV polio
vaccination schedule, Brazil’s National Immunization Program
initiated plans for IPV use following worldwide eradication of
polio, when only IPV use will be recommended .
Introduction of IPV in Brazil’s National Immunization Program also
meets updated recommendations from WHO’s Strategic
Advisory Group of Experts in November 2012 that all countries
introduce at least 1 dose of IPV in routine infant immunization
schedules prior to withdrawal of type-2 OPV virus from
trivalent OPV to mitigate risks of poliomyelitis associated with
type-2 VDPVs .
Several considerations were important for the choice of a
sequential IPV-OPV schedule in Brazil’s National Immunization
Program. Despite limited experience with sequential IPV-OPV
schedules for routine infant immunizations in Latin America ,
experiences from the United States and countries in other regions
have demonstrated success in maintaining elimination of wild
poliovirus and preventing VAPP . Several other Latin American
countries, including Costa Rica and Mexico, have maintained
national polio immunization days with OPV following an IPV-only
routine infant immunization schedule , as recommended by
PAHO . In Brazil, the decision to maintain 1 NID with OPV
was based on reducing risk of poliovirus transmission in the
event of a WPV or VDPV importation and maintaining annual
outreach activities to difficult-to-access populations during
campaigns. Financial sustainability of IPV introduction was also
considered in the context of increased government commitment to
the national immunization program with the introduction of
new childhood vaccines in the past decade, including oral
rotavirus vaccine, and pneumococcal and meningococcal serogroup C
conjugate vaccines . Finally, IPV introduction in Brazil
contributes to equitable access to recommended vaccines among all
Brazilian children, in accordance with the founding principles of
Brazil’s national immunization program [3, 19].
Interpretation of immunization coverage and AFP
surveillance data from Brazil is subject to several limitations.
Declining reporting rates of VAPP since certification of polio
elimination likely reflect underreporting of AFP cases [22, 23,
36]; incidence of VAPP in Brazil, while still rare, was believed to
be higher than reported. Administrative coverage estimates are
based on numbers of doses administered rather than children
vaccinated, and municipal estimates of coverage are unreliable
because doses are recorded by health center rather than place of
residence. Brazil’s national immunization program has initiated
a national immunization registry to provide more reliable
immunization coverage data . Data from immunization
coverage surveys were only available for selected urban populations
. Concerns about heterogeneous polio immunization
coverage and pockets of susceptible populations, especially in rural
areas with conditions favorable to poliovirus transmission,
motivated maintenance of 2 OPV doses in the routine polio
immunization schedule and continuation of 1 annual polio
immunization day for children aged <5 years.
With the international purchase of IPV, Brazil’s Ministry
of Health launched an initiative with 3 national vaccine
manufacturers—Bio-Manguinhos Institute of the Oswaldo Cruz
Foundation in Rio de Janeiro, Butantan Institute in São Paulo,
and Ezequiel Dias Foundation in Belo Horizonte—to produce a
heptavalent vaccine for the national immunization program,
containing diphtheria, tetanus, pertussis, Hib, HepB, IPV, and
meningococcal serogroup C conjugate antigens. Availability of a
nationally produced combination product containing IPV would
reduce the number of vaccination visits and injections, and
potentially reduce medical waste. In addition, production of
combination vaccines in single-dose vials can reduce vaccine wastage
without substantially increasing requirements for cold storage
capacity. Brazil’s national immunization program continually
works to expand access to safe and effective vaccines for all
Acknowledgments. We would like to thank health professionals in
immunizations, disease surveillance, and public health laboratories at all levels
in the Brazilian health system, and the communications staff for their work
over the past 29 years to maintain Brazil polio free; the work of these
individuals demonstrates their commitment to public health and exemplifies
the principles of the Brazilian Unified Health System. We would especially
like to acknowledge the work of vaccination teams to reach children and
achieve high vaccine coverage, both in routine immunizations and during
campaigns throughout the country. The Brazilian National Technical
Advisory Committee for Immunizations has provided essential support for the
National Immunization Program, as well as important linkages with professional
organizations and the Brazilian population. We thank Concepción Estívariz
from the US Centers for Disease Control and Prevention (CDC) for
background information and helpful suggestions for revision of the manuscript.
Disclaimer. The findings and conclusions in this report are those of the
authors and do not necessarily represent the official position of the CDC.
Supplement sponsorship. This article is part of a supplement entitled
“The Final Phase of Polio Eradication and Endgame Strategies for the
PostEradication Era,” which was sponsored by the Centers for Disease Control
Potential conflicts of interest. Carla Domingues, Sirlene Pereira, Ana
Carolina Marreiros, and Nair Menezes are employed by the Brazilian
Ministry of Health, which purchases inactivated polio vaccine for use in the
national immunization program. In Brazil, inactivated polio vaccine is
purchased in bulk from Sanofi Pasteur and distributed by Bio-Manguinhos
Institute, a public vaccine manufacturer funded by the Brazilian Ministry of
Health. All other authors report no potential conflicts.
All authors have submitted the ICMJE Form for Disclosure of Potential
Conflicts of Interest. Conflicts that the editors consider relevant to the
content of the manuscript have been disclosed
1. World Health Organization. Polio vaccines and polio immunization in the pre-eradication era: WHO position paper . Wkly Epidemiol Rec 2010 ; 85 : 213 - 28 .
2. Pan American Health Organization . Immunization: prioritizing vunerable populations . In: Final report of the XVIII Technical Advisory Group (TAG) meeting on vaccine-preventable diseases of the Pan American Health Organization . Washington, DC: Pan American Health Organization , 2011 : 15 - 6 .
3. Ministry of Health. Programa Nacional de Imunizações-30 anos. Série C Projetos e Programas e Relatórios . Brasília, Brazil: Ministry of Health , 2003 .
4. Ministry of Health. Informe Técnico da Introdução da Vacina Inativada Poliomielite . Departamento de Vigilância Epidemiológica . http:// portal.saude. gov.br/portal/arquivos/pdf/informe_introducao_vacina_ inativada_polio_vip_2012 .pdf. Accessed 1 October 2013 .
5. Risi JB Jr. The control of poliomyelitis in Brazil . Rev Infect Dis 1984 ; 6 ( suppl 2 ): S400 - 3 .
6. Nascimento DR . As campanhas de vacinação contra a poliomielite no Brasil (1960-1990) . Ciência e Saúde Coletiva 2011 ; 16 : 501 - 11 .
7. Olive JM , Risi JB Jr., de Quadros CA. National immunization days: experience in Latin America . J Infect Dis 1997 ; 175 (suppl 1): S189 - 93 .
8. Ministry of Health. Programa Nacinal de Imunizações-25 anos. Série A Normas e Manuais Técnicos . Brasília, Brazil: Fundação Nacional de Saúde, Brazilian Ministry of Health , 1998 .
9. Silva SJM . A vigilância da Poliomielite-Paralisias Flácidas Agudas . Revista Brasileira de Enfermagem 2005 ; 58 : 110 - 1 .
10. de Brito Bastos NC , Carvalho Filho ES , Schatzmayr H , Homma A , Chaves J. Antipoliomyelitis program in Brazil; a serologic study of immunity levels . Bull Pan Am Health Organ 1974 ; 8 : 54 - 65 .
11. Patriarca PA , Laender F , Palmeira G , et al. Randomised trial of alternative formulations of oral poliovaccine in Brazil . Lancet 1988 ; 1 : 429 - 33 .
12. Patriarca PA , Wright PF , John TJ. Factors affecting the immunogenicity of oral poliovirus vaccine in developing countries: review . Rev Infect Dis 1991 ; 13 : 926 - 39 .
13. World Health Organization Collaborative Study Group on Oral Poliovirus Vaccine . Factors affecting the immunogenicity of oral poliovirus vaccine: a prospective evaluation in Brazil and the Gambia . J Infect Dis 1995 ; 171 : 1097 - 106 .
14. Schatzmayr HG , Maurice Y , Fujita M , de Fillipis AM . Serological evaluation of poliomyelitis oral and inactivated vaccines in an urban lowincome population at Rio de Janeiro , Brazil. Vaccine 1986 ; 4 : 111 - 3 .
15. Salas-Peraza D , Avila-Aguero ML , Morice-Trejos A. Switching from OPV to IPV: are we behind the schedule in Latin America? Expert Rev Vaccines 2010 ; 9 : 475 - 83 .
16. Stewardson AJ , Roberts JA , Beckett CL , et al. Imported case of poliomyelitis , Melbourne, Australia, 2007 . Emerg Infect Dis 2009 ; 15 : 63 - 5 .
17. Centers for Disease Control and Prevention. Outbreaks following wild poliovirus importations-Europe , Africa, and Asia, January 2009 - September 2010 . MMWR Morb Mortal Wkly Rep 2010 ; 59 : 1393 - 9 .
18. Teixeira AM , Samad SA , Souza MA , Segatto TC , Morice A , Flannery B. Brazilian experience with rapid monitoring of vaccination coverage during a national rubella elimination campaign . Rev Panam Salud Publica 2011 ; 30 : 7 - 14 .
19. Barata RB , Ribeiro MC , de Moraes JC , Flannery B , Vaccine Coverage Survey G. Socioeconomic inequalities and vaccination coverage: results of an immunisation coverage survey in 27 Brazilian capitals , 2007 - 2008 . J Epidemiol Community Health 2012 ; 66 : 934 - 41 .
20. Domingues CM , Teixeira AM , Carvalho SM . National immunization program: vaccination, compliance and pharmacovigilance . Rev Inst Med Trop Sao Paulo 2012 ; 54 (suppl 18): S22 - 7 .
21. Paim J , Travassos C , Almeida C , Bahia L , Macinko J. The Brazilian health system: history , advances, and challenges. Lancet 2011 ; 377 : 1778 - 97 .
22. de Oliveira LH , Struchiner CJ . Vaccine-associated paralytic poliomyelitis: a retrospective cohort study of acute flaccid paralyses in Brazil . Int J Epidemiol 2000 ; 29 : 757 - 63 .
23. Teixeira-Rocha ES , Carmo EH , Tavares-Neto J. The occurrence of vaccine-associated paralytic poliomyelitis in Brazil , 1995 to 2001 . Rev Panam Salud Publica 2005 ; 18 : 21 - 4 .
24. Kew OM , Sutter RW , de Gourville EM , Dowdle WR , Pallansch MA. Vaccine-derived polioviruses and the endgame strategy for global polio eradication . Annu Rev Microbiol 2005 ; 59 : 587 - 635 .
25. World Health Organization: Poliomyelitis. WHO-recommended standards for surveillance of selected vaccine- preventable diseases WHO/ V&B/0301. Geneva: WHO , 2008 : 31 - 4 .
26. Mello MLR , Moraes JC , Barbosa HA , Flannery B. Participation in national polio immunization days: results of a vaccine coverage survey among children in 27 Brazilian cities . Rev Bras Epidemiol 2010 ; 13 : 1 - 11 .
27. Sociedade Brasileira de Pediatria. Novo Calendário de Vacinas da Sociedade Brasileira de Pediatria SBP Notícias . Vol 57. Sociedade Brasileira de Pediatria, 2009 . http://www.sbp. com.br/img/sbp_noticias/sbp57 .pdf. Accessed 1 October 2013 .
28. Ministry of Health. Manual dos Centros de Referência para Imunobiológicos Especiais . Série A. Normas e Manuais Técnicos . 3a edição. Brasília, Brazil: Ministry of Health , 2006 .
29. Plotkin SA , Vidor E. Poliovirus vaccine-inactivated . In: Plotkin SA, Orenstein WA , Offit P, eds. Vaccines. 5th ed . Philadelphia, PA: Saunders Elsevier, 2008 : 605 - 29 .
30. Vieira JC , Carvalho MT , Checchia RL , Trombiere M , Flannery B. Survey of rubella knowledge and acceptability of rubella vaccination among Brazilian adults prior to mass vaccination . Rev Panam Salud Publica 2011 ; 30 : 335 - 41 .
31. Schoub BD . Introduction of inactivated polio vaccine (IPV) into the routine immunization schedule of South Africa . Vaccine 2012 ; 30 (suppl 3): C35 - 7 .
32. World Health Organization. Vaccine introduction [database online] . http://www.who.int/immunization_monitoring/data/year_vaccine_ introduction.xls. Accessed 1 October 2013 .
33. Estivariz CF , Pallansch MA , Anand A , et al. Poliovirus vaccination options for achieving eradication and securing the endgame . Curr Opin Virol 2013 ; 3 : 309 - 15 .
34. Inactivated poliovirus vaccine following oral poliovirus vaccine cessation . Wkly Epidemiol Rec 2006 ; 81 : 137 - 44 .
35. Meeting of the Strategic Advisory Group of Experts on Immunization, November 2012-conclusions and recommendations . Wkly Epidemiol Rec 2013 ; 88 : 1 - 16 .
36. Andrus JK , Strebel PM , de Quadros CA , Olive JM . Risk of vaccineassociated paralytic poliomyelitis in Latin America , 1989 - 91 . Bull World Health Organ 1995 ; 73 : 33 - 40 .