A study from China reports that,
"Measles remains a major threat to human health despite widespread vaccination. While we know that maternal antibodies can impair vaccine-induced immunity, the relative contributions of pre-existing immunity levels, maternal and infant characteristics on vaccine responses remain unclear, hampering evidence-based vaccination policy development. Here we combine serological data from 1,505 individuals (aged 0–12 years) in a mother–infant cohort and in a child cohort with empirical models to reconstruct antibody trajectories from birth. We show that while highly heterogeneous across a population, measles antibody evolution is strongly predictive from birth at the individual level, including following vaccination. Further, we find that caesarean section births were linked with 2.56 (95% confidence interval: 1.06–6.37) increased odds of primary vaccine failure, highlighting the long-term immunological consequences of birth route.
Finally, we use our new understanding of antibody evolution to critically assess the population-level consequences of different vaccination schedules, the results of which will allow country-level evaluations of vaccine policy."
In brief, epidemiological data from China, where the first dose of the measles vaccine is given at eight months of age, shows about a third of the individuals who developed measles between 2013 and 2019 had been vaccinated.
PS: Why this happens? Mainly because of Passive Immmunity at play here causing what's called "Immune Blunting". During the first few months when life begins, maternal antibodies cross the placenta and later on the antibodies from the mother's milk protects the newborn. This type of immune protection is known as “passive immunity,” and differs from “active immunity,” which develops in an individual following vaccination or natural infection with a pathogen.
Passive immunity and active immunization often overlap and can interfere with each other in a phenomenon known as immune blunting. For instance, circulating maternal anti-measles virus antibodies can prevent an infant’s B cells from producing its own antibodies in response to measles vaccination or infection with measles virus.
Maternal anti-measles virus antibodies have a half-life of 181 days. Because such antibodies can block the infant’s ability to produce anti-measles antibodies, administration of the first dose of the measles vaccine prior to 12 months of age may not result in optimal vaccine-induced antibody concentrations.
The vaccine policy needs a revist because in many countries like the US, UK, Australia, NZ etc the first dose is 12 months or later but in some countries it's 8 months (China), 9 months (SL) etc.
The CDC recommendation is MMR starting with the first dose at 12 through 15 months of age, and the second dose at 4 through 6 years of age.
"Measles remains a major threat to human health despite widespread vaccination. While we know that maternal antibodies can impair vaccine-induced immunity, the relative contributions of pre-existing immunity levels, maternal and infant characteristics on vaccine responses remain unclear, hampering evidence-based vaccination policy development. Here we combine serological data from 1,505 individuals (aged 0–12 years) in a mother–infant cohort and in a child cohort with empirical models to reconstruct antibody trajectories from birth. We show that while highly heterogeneous across a population, measles antibody evolution is strongly predictive from birth at the individual level, including following vaccination. Further, we find that caesarean section births were linked with 2.56 (95% confidence interval: 1.06–6.37) increased odds of primary vaccine failure, highlighting the long-term immunological consequences of birth route.
Finally, we use our new understanding of antibody evolution to critically assess the population-level consequences of different vaccination schedules, the results of which will allow country-level evaluations of vaccine policy."
In brief, epidemiological data from China, where the first dose of the measles vaccine is given at eight months of age, shows about a third of the individuals who developed measles between 2013 and 2019 had been vaccinated.
PS: Why this happens? Mainly because of Passive Immmunity at play here causing what's called "Immune Blunting". During the first few months when life begins, maternal antibodies cross the placenta and later on the antibodies from the mother's milk protects the newborn. This type of immune protection is known as “passive immunity,” and differs from “active immunity,” which develops in an individual following vaccination or natural infection with a pathogen.
Passive immunity and active immunization often overlap and can interfere with each other in a phenomenon known as immune blunting. For instance, circulating maternal anti-measles virus antibodies can prevent an infant’s B cells from producing its own antibodies in response to measles vaccination or infection with measles virus.
Maternal anti-measles virus antibodies have a half-life of 181 days. Because such antibodies can block the infant’s ability to produce anti-measles antibodies, administration of the first dose of the measles vaccine prior to 12 months of age may not result in optimal vaccine-induced antibody concentrations.
The vaccine policy needs a revist because in many countries like the US, UK, Australia, NZ etc the first dose is 12 months or later but in some countries it's 8 months (China), 9 months (SL) etc.
The CDC recommendation is MMR starting with the first dose at 12 through 15 months of age, and the second dose at 4 through 6 years of age.
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