| Clin Infect Dis 2000 Jul;31(1):110-9 | Related
Articles, |
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Epidemiol Infect 2000 Apr;124(2):263-71 |
Secondary measles vaccine failures identified
by measurement of IgG avidity: high occurrence among teenagers vaccinated at a
young age.
Paunio M, Hedman K, Davidkin I, Valle M, Heinonen OP, Leinikki P, Salmi A,
Peltola H.
Department of Public Health, University of Helsinki, Finland.
Failure to seroconvert (primary vaccine failure) is believed to be the
principal reason (approx. > 95%) why some vaccinees remain susceptible to
measles and is often attributed to the persistence of maternal antibodies in
children vaccinated at a young age. Avidity testing is able to separate primary
from secondary vaccine failures (waning and/or incomplete immunity), but has
not been utilized in measles epidemiology. Low-avidity (LA) and high-avidity
(HA) virus-specific IgG antibodies indicate primary and secondary failure,
respectively. Measles vaccine failures (n = 142; mean age 10.1 years, range
2-22 years) from an outbreak in 1988-9 in Finland were tested for measles-virus
IgG avidity using a protein denaturating EIA. Severity of measles was recorded
in 89 failures and 169 non-vaccinees (mean age 16.2 years, range 2-22 years).
The patients with HA antibodies (n = 28) tended to have clinically mild measles
and rapid IgG response. Among failures vaccinated at < 12, 12-15 and > 15
months of age with single doses of Schwarz-strain vaccine in the 1970s, 50 (95%
CI 1-99), 36 (CI 16-56) and 25% (CI 8-42) had HA antibodies, respectively. When
a single measles, mumps and rubella (MMR) vaccine had been given after 1982 at
15 months of age, only 7% (CI 0-14) showed HA antibodies. Omitting re-vaccinees
and those vaccinated at < 15 months, Schwarz-strain recipients had 3.6 (CI
1.1-11.5) higher occurrence of HA responses compared to MMR recipients. Apart
from one municipality, where even re-vaccinees had high risk of primary
infection, 89% (CI 69 to approximately 100) of the infected re-vaccinees had an
HA response. Secondary measles-vaccine failures are more common than was more
previously thought, particularly among individuals vaccinated in early life,
long ago, and among re-vaccinees. Waning immunity even among individuals
vaccinated after 15 months of age, without the boosting effect of natural
infections should be considered a relevant possibility in future planning of
vaccination against measles.
PMID: 10813152 [PubMed - indexed for MEDLINE]
|
J Virol 2000 May;74(10):4652-7 |
Successful vaccine-induced seroconversion by
single-dose immunization in the presence of measles virus-specific maternal
antibodies.
Schlereth B, Rose JK, Buonocore L, ter Meulen V, Niewiesk S.
Institute of Virology and Immunobiology, University of Wuerzburg, 97078
Wurzburg, Germany.
In humans, maternal antibodies inhibit successful immunization against measles,
because they interfere with vaccine-induced seroconversion. We have
investigated this problem using the cotton rat model (Sigmodon hispidus). As in
humans, passively transferred antibodies inhibit the induction of measles virus
(MV)-neutralizing antibodies and protection after immunization with MV. In
contrast, a recombinant vesicular stomatitis virus (VSV) expressing the MV
hemagglutinin (VSV-H) induces high titers of neutralizing antibodies to MV in
the presence of MV-specific antibodies. The induction of neutralizing
antibodies increased with increasing virus dose, and all doses gave good
protection from subsequent challenge with MV. Induction of antibodies by VSV-H
was observed in the presence of passively transferred human or cotton rat
antibodies, which were used as the models of maternal antibodies. Because MV
hemagglutinin is not a functional part of the VSV-H envelope, MV-specific
antibodies only slightly inhibit VSV-H replication in vitro. This dissociation
of function and antigenicity is probably key to the induction of a neutralizing
antibody in the presence of a maternal antibody.
PMID: 10775601 [PubMed - indexed for MEDLINE]
|
Eur J Immunol 1998 Dec;28(12):4138-48 |
Influence of maternal antibodies on vaccine
responses: inhibition of antibody but not T cell responses allows successful
early prime-boost strategies in mice.
Siegrist CA, Barrios C, Martinez X, Brandt C, Berney M, Cordova M, Kovarik
J, Lambert PH.
W.H.O. Collaborating Center for Neonatal Vaccinology, Department of Pathology,
University of Geneva Medical School, Switzerland.
Claire-Anne.Siegrist@medecine.unige.ch
The transfer of maternal antibodies to the offspring and their inhibitory
effects on active infant immunization is an important factor hampering the use
of certain vaccines, such as measles or respiratory syncytial virus vaccine, in
early infancy. The resulting delay in protection by conventional or novel
vaccines may have significant public health consequences. To define
immunization approaches which may circumvent this phenomenon, experiments were
set up to further elucidate its immunological bases. The influence of maternal
antibodies on antibody and T cell responses to measles hemagglutinin (MV-HA)
were analyzed following MV-HA immunization of pups born to immune or control
BALB/c mothers using four different antigen delivery systems: live or
inactivated conventional measles vaccine, a live recombinant canarypox vector
and a DNA vaccine. High levels (> 5 log10) of maternal anti-HA antibodies
totally inhibited antibody responses to each of the vaccine constructs, whereas
normal antibody responses were elicited in presence of lower titers of maternal
antibodies. However, even high titers of maternal antibodies affected neither
the induction of vaccine-specific Th1/Th2 responses, as assessed by
proliferation and levels of IFN-gamma and IL-5 production, nor CTL responses in
infant mice. On the basis of these unaltered T cell responses, very early
priming and boosting (at 1 and 3 weeks of age, respectively) with live measles
vaccine allowed to circumvent maternal antibody inhibition of antibody
responses in pups of immune mothers. This was confirmed in another immunization
model (tetanus toxoid). It suggests that effective vaccine responses may be
obtained earlier in presence of maternal antibodies through the use of
appropriate immunization strategies using conventional or novel vaccines for
early priming.
PMID: 9862350 [PubMed - indexed for MEDLINE]
| Pediatr Infect Dis J 1998 Apr;17(4):313-6 | Related
Articles, |
| Vaccine 1998 Apr;16(6):564-8 | Related
Articles, |
| J Infect Dis 1997 Mar;175(3):524-32 | Related
Articles, |
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Can J Public Health 1996 Mar-Apr;87(2):97-100 |
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Measles immunization strategy: measles
antibody response following MMR II vaccination of children at one year of age.
Ratnam S, West R, Gadag V, Burris J.
Newfoundland Public Health Laboratory, Department of Health, Faculty of
Medicine, Memorial University of Newfoundland, St. John's.
Measles antibody levels were determined by the plaque reduction neutralization
(PRN) test in 580 one-year-old children before vaccination and four to six
weeks after MMR II vaccination. Fifty-one (8.8%) had maternally derived measles
antibody at prevaccination, and this was more common among children of women
born before 1967 (10.6%) vs. 4.3%; p < 0.01). Among those with maternal
antibody, only 22 (43.1%) responded with a protective PRN titre of over 120, in
contrast to 463 (87.5%) of the 529 without maternal antibody at prevaccination
(p < 0.0001). Also, the geometric mean titre was significantly lower for the
former (114.1 vs. 378.5; p < 0.0001). Overall, 15 (2.6%) of the 580 children
had no antibody response after vaccination, and a further 80 (13.8%) had a
subprotective response (PRN titre < 120). This lack of response could not be
attributed entirely to the presence of maternal measles antibody at the time of
vaccination. The MMR II vaccine may not be sufficiently immunogenic in inducing
adequate measles antibody response after a single dose given at one year of
age.
Publication Types:
·
Clinical Trial
·
Controlled Clinical Trial
PMID: 8753636 [PubMed - indexed for MEDLINE]
|
Epidemiol Infect 1995 Dec;115(3):603-21 |
Measles vaccination policy.
Williams BG, Cutts FT, Dye C.
Epidemiology Research Unit, Johannesburg, South Africa.
Where immunization campaigns locally eliminate measles, it will be important to
identify the vaccination policy most likely to prevent future epidemics. The
optimum age for vaccination depends on the rate of decline of maternal
antibody, because the presence of antibody reduces vaccine efficacy. The first
part of this paper contains a quantitative reappraisal of the data on antibody
decline and seroconversion rates by age. The decline in maternal antibody
protection follows delayed exponentials, with delays of 2-4 months, and
subsequent half-lives of 1-2 months. Using this result in an analytical
mathematical model we find that the optimal age to administer a single dose of
vaccine to children, which is independent of vaccine coverage, lies within the
range 11-19 months. We also show that, where the optimal age cannot be met, it
is better to err towards late rather than early vaccination. There are
therefore two reasons why developing countries, which presently vaccinate
during infancy because measles transmission rates are high should eventually
switch to the second year of life. The possible gains from two-dose vaccination
schedules are explored with respect to both coverage and efficacy. A two-dose
schedule will be beneficial, in principle, only when there is a need to
increase net vaccine efficacy, after coverage has been maximized with a
one-dose schedule.
PMID: 8557092 [PubMed - indexed for MEDLINE]
|
Cent Afr J Med 1995 Aug;41(8):241-5 |
Questioning the level of efficacy of the
measles vaccine in use in Zimbabwe.
Marufu T, Siziya S, Manyame B, Xaba E, Silape-Marufu Z, Zimbizi P, Ruwodo C,
Mason E, Matchaba-Hove RB, Mudyarabikwa O.
University of Zimbabwe Medical School, Department of Community Medicine,
Harare, Zimbabwe.
A prospective study was carried out between 1987 and 1989 in the City of Gweru
(Zimbabwe) to assess the efficacy of the measles vaccine. The vaccine efficacy
assessment was carried out on an epidemiological basis by relating measles
transmission in the vaccinated and unvaccinated children aged 10 to 23 months.
Measles cases were identified on the basis of a standard case definition and
data on occurrence of measles cases was collected through an active
surveillance system. Efficacies of 73 pc, 82 pc and 77 pc were calculated for
the years 1987, 1988 and 1989 respectively. Over the three year period mean
efficacy was found to be 77 pc (95 pc confidence interval 75 to 79 pc). The
vaccine efficacies found in this study were lower than 85 pc which is the
officially accepted efficacy of the measles vaccine that is in use in Zimbabwe. The low vaccine efficacy found in this study is attributed to the fact that the
measles vaccine is applied (at nine months of age) when probably 10 to 20 pc of
children still have prenatally acquired maternal antibodies. It is suggested
that further studies be carried out in Zimbabwe to enable the country to define
the way forward.
PMID: 7585910 [PubMed - indexed for MEDLINE]
|
Bull World Health Organ 1991;69(1):1-7 |
Principles of measles control.
Cutts FT, Henderson RH, Clements CJ, Chen RT, Patriarca PA.
Immunization Division, Centers for Disease Control, Atlanta, GA 30333.
WHO's Expanded Programme on Immunization has significantly helped to reduce
global morbidity and mortality from measles. Recently, some African countries
with high vaccine coverage levels have reported measles outbreaks in children
above the current target age group for immunization. Outbreaks such as these
are to be expected, unless close to 100% of the population are immunized with a
vaccine which is 100% effective. Success of an immunization programme requires
identification of the distribution and ages of susceptible children and
reduction of their concentration throughout the community. Priority should be
given to urban and densely populated rural areas. In large urban areas, high
coverage of infants must be achieved soon after the age at which they lose
their maternal antibodies and become susceptible. This will be facilitated by
the introduction of high-dose measles vaccines which can be given at 6 months
of age. Where measles incidence is increasing among children aged over 2 years,
immunization of older children may be considered during contacts with the
health care system, or at primary school entry, if this does not divert
resources from immunization of younger children. Health workers should be
informed of the predicted changes in measles epidemiology following
immunization. The collection, analysis and use of data on measles (vaccine
coverage, morbidity and mortality) should be improved at all levels of the
health care system in order to monitor the immunization programme's overall
impact, identify pockets of low coverage, and allow early detection of and
response to measles outbreaks.
Publication Types:
·
Review
·
Review, Tutorial
PMID: 2054914 [PubMed - indexed for MEDLINE]
| Med Trop (Mars) 1991 Apr-Jun;51(2):215-8 | Related
Articles, |
|
An Esp Pediatr 1984 Jun;20(9):847-53 |
[Anti-measles antibodies in the first 2 years
of life]
[Article in Spanish]
Echevarria JM, Sainz C, Monton JL, Gonzalez F, Crespo E, Morales E, Cortes
M, Taracena B, Najera R.
In order to achieve a better understanding of the epidemiology of measles in Spain
to foster vaccination policy in our country, we have conducted a serological
survey of measles antibodies in children between birth and two years of life in
the urban population of Madrid. Authors have established the rate at which
maternal antibodies are lost in these children below 15 months of life. The
results indicate that, in general maternal antibodies have already disappeared
at 9 months. Vaccination can thus be indicated around this age.
PMID: 6486579 [PubMed - indexed for MEDLINE]
| Med J Aust 1983 Nov 12;2(10):488-91 | Related
Articles, |
| Int J Epidemiol 1983 Sep;12(3):340-3 | Related
Articles, |
|
Rev Infect Dis 1983 May-Jun;5(3):452-9 |
Measles: summary of worldwide impact.
Assaad F.
Nearly every measles infection results in well-recognized clinical disease. In
nonimmunized populations almost every child will get measles early in life. The
universality of the disease in nonimmunized communities, particularly those in
the developing world, has led to a more or less passive acceptance of measles
as an unavoidable risk of early life. The clinical spectrum of measles ranges
from a mild, self-limiting illness to a fatal disease. Conditions encountered
mainly in the developing world, e.g., unfavorable nutrition, high risk of
concurrent infection, and inadequate case management -- particularly at home --
favor the development of complications and adverse outcome. Conversely, good
clinical management of an otherwise healthy child, a situation seen mostly in
the developed world, greatly influences the course of the disease. Hence many
in the medical profession believe that measles is a mild disease except among
populations living under particularly unfavorable conditions. Measles vaccine
is effective in preventing disease in the individual and in controlling it in
the community if it is given at the critical age when maternal antibodies wane
and the risk of natural infection increases sharply and if a high immunization
rate is maintained in the target population. The experience with immunization,
particularly in sub-saharan Africa, is rewarding: mothers who had previously
accepted measles as an unavoidable risk clamour for immunization of their
children once its effectiveness has been demonstrated. No reason exists for
measles to claim its present toll of morbidity and mortality. With extension of
the Expanded Programme on Immunization of the World Health Organization, the
impact of measles should progressively decline.
PMID: 6878998 [PubMed - indexed for MEDLINE]
| : Clin Pediatr (Phila) 1979 Mar;18(3):155-6, 161-3, 167 | Related
Articles, |
From the article: "In
the early 1960's, it was believed that transplacentally-acquired antibody
did not persist much beyond 6 months of age. Hence, many children were
vaccinated before 1 year of age in accordance with early
recommendations. In the mid-1960's, however, maternal antibody was
detected in some infants as late as 11 months of age. Vaccination
before 1 years was then implicated as a contributing cause of vaccine
failure. More recently, maternal antibody was detected in some infants
as late as 12 months of age, using a sensitive virus neutralization assay."
Publication Types:
|
Infection 1978;6(5):207-10 |
The influence of maternally derived antibody
on the efficacy of further attenuated measles vaccine.
Stewien KE, Barbosa V, de Lima OS, Osiro K.
The natural decline of passively acquired maternal antibody titers and the
influence of these antibodies on the efficacy of live, further attenuated
measles vaccine were studied in 7 to 12 month old infants.
Hemagglutination-inhibition (HI) antibody titers were determined in the pre-
and postvaccination sera. HI antibodies at low titers were detected in 20 (46%)
of the 43 infants investigated, in five of six infants at seven months and two
of nine infants at 12 months of age. The serological conversion rate following
vaccination of the infants exhibiting transplacental maternal antibody was as
low as 38%, in contrast with 100% sero-conversion of the infants without
measurable antibodies of maternal origin. HI antibody titers were low in the
infants seven to nine months of age, reflecting poor antibody responses to the
administered vaccine. For the 12 month old infants the geometrical mean
antibody titer was 1 : 52. It is concluded that transplacental maternal
antibody, even at low concentration, inhibits induction of HI antibody in the
vaccinees and therefore measles vaccination must be initiated after 12 months
of age in order to achieve successful immunization of the children. Infants who
receive the vaccine before their first birthday have to be revaccinated at or
after 15 months of age.
PMID: 730390 [PubMed - indexed for MEDLINE]
| JAMA 1977 Jan 24;237(4):347-51 | Related
Articles, |
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J Pediatr 1977 Nov;91(5):715-8 |
Persistence of maternal antibody in infants
beyond 12 months: mechanism of measles vaccine failure.
Albrecht P, Ennis FA, Saltzman EJ, Krugman S.
A serologic study was made in 34 children immunized against measles at the age
of 12 months. Using a sensitive virus neutralization test, it was found that
many of the children had pre-existing maternal antibody to measles virus.
Children with high pre-existing antibody titers failed to seroconvert. Children
with lower pre-existing antibody titers seroconverted, but the resulting
antibody titer was significantly lower than in children without pre-existing
antibody titer. The results of this study demonstrate a probably mechanism for
measles vaccine failure in 12-month-old children and support the recommendation
of the Public Health Service Advisory Committee on Immunization Practices to
postpone measles vaccination to 15 months of age.
PMID: 909009 [PubMed - indexed for MEDLINE]
| Am J Epidemiol 1975 Jun;101(6):527-31 | Related
Articles,
|