I am delayed in asking...needed to find my 'summary question'. If my information is not correct please clarify, thank you.
Given the sad state of likely global immunizations, specifically measles I have read the passive immunity from mom to newborn is not very good... convention being "protective" maternal antibodies are present ~ 9+ months post birth. However, titres are minimal within a couple months. I find it counterintuitive, what I read indicated mom's with natural immunity may offer their new born a shorter window of passive antibodies cf those who were vaccinated with MMR.
This may be simply an academic exercise yet there is a vast number of newborns who are especially vulnerable to contracting measles & no fault or lack of due diligence on the part of their mothers.
I am also aware MMR vaccine effectiveness with early vaccination is lower than with vaccination at 14 mo's ( ~76% at 6 mo's, rising to 95% at 9 months) with permanently reduced antibody titers at a later age, even after follow-up vaccination(s). These effects are greatest when vaccinated at 6 months of age and decrease as vaccination occurs at a later age. In addition, to those who receive the MMR prior to the established timing for their 1st dose, any previous dosage is MMR0.
Clearly, we cannot vaccinated pregnant women but we could discuss a 'booster dose' of MMR such as the recommended RSV (late 2nd or early 3rd trimester), as such off-label.
OMG the tragic consequences of a newborn contracting measles.
Thanks for the thoughtful message! The MMR can't be given to the pregnant parent because it is a live attenuated vaccine. The antibodies that cross the placenta from mom to baby during pregnancy are protein and, as a result, are susceptible to degradation over time. They likely last anywhere form 3 months (shortest) to 9 month (longest). Early MMR vaccination in newborns is typically not done until 12 months of age due to the fact that the anti-measles antibodies that crossed the placenta into the baby do their job and bind and block the antigen in the vaccine from sparking a robust immune response. At 12 months the antibodies from mom are gone and the vaccine sparks a robust response. The MMR will be given early if the baby lives in a region where there is an outbreak of measles. The earliest timepoint would be 6 months and is considered as dose 0 because - as you noted - it is not fully effective. The recommendation is the full series starting at 12 months. Keep in mind that if the mother had never received the MMR this effect would not hinder the immune response. However, vaccination rates in the past in the US were quite good and it is assumed mom had the MMR. Vaccination records back in the day were typically on paper (mine were from the early 1970s) and unable to be tracked if your clinic closed and paperwork is gone. I hope that helps!
Respectfully, Dr. Bernard I am aware of what you outlined & apology for not be clearer in my question or concern for what I believe is the majority of not a large percentage of newborns are susceptible to contracting measles.
The conventionsl paradigm being babies born to mother's who have developed measles antibodies from natural exposure or vaccination are protected throughout their initial "12 months" is flawed if I understand correctly from what I have read.
These passive antibodies wane significantly during the initial post partum period such that their is limited protection after 3-6 months.
If my understanding is correct (stand corrected) newborns would have little to no competing maternal antibodies post 6 months from delivery. Once again if this has been established should we not be evaluating when the recommended 1st dose of MMR should be offered/administered. This would then not be considered MMR0.
I am delayed in asking...needed to find my 'summary question'. If my information is not correct please clarify, thank you.
Given the sad state of likely global immunizations, specifically measles I have read the passive immunity from mom to newborn is not very good... convention being "protective" maternal antibodies are present ~ 9+ months post birth. However, titres are minimal within a couple months. I find it counterintuitive, what I read indicated mom's with natural immunity may offer their new born a shorter window of passive antibodies cf those who were vaccinated with MMR.
This may be simply an academic exercise yet there is a vast number of newborns who are especially vulnerable to contracting measles & no fault or lack of due diligence on the part of their mothers.
I am also aware MMR vaccine effectiveness with early vaccination is lower than with vaccination at 14 mo's ( ~76% at 6 mo's, rising to 95% at 9 months) with permanently reduced antibody titers at a later age, even after follow-up vaccination(s). These effects are greatest when vaccinated at 6 months of age and decrease as vaccination occurs at a later age. In addition, to those who receive the MMR prior to the established timing for their 1st dose, any previous dosage is MMR0.
Clearly, we cannot vaccinated pregnant women but we could discuss a 'booster dose' of MMR such as the recommended RSV (late 2nd or early 3rd trimester), as such off-label.
OMG the tragic consequences of a newborn contracting measles.
Appreciatly your, JJF Phm 🇨🇦
Thanks for the thoughtful message! The MMR can't be given to the pregnant parent because it is a live attenuated vaccine. The antibodies that cross the placenta from mom to baby during pregnancy are protein and, as a result, are susceptible to degradation over time. They likely last anywhere form 3 months (shortest) to 9 month (longest). Early MMR vaccination in newborns is typically not done until 12 months of age due to the fact that the anti-measles antibodies that crossed the placenta into the baby do their job and bind and block the antigen in the vaccine from sparking a robust immune response. At 12 months the antibodies from mom are gone and the vaccine sparks a robust response. The MMR will be given early if the baby lives in a region where there is an outbreak of measles. The earliest timepoint would be 6 months and is considered as dose 0 because - as you noted - it is not fully effective. The recommendation is the full series starting at 12 months. Keep in mind that if the mother had never received the MMR this effect would not hinder the immune response. However, vaccination rates in the past in the US were quite good and it is assumed mom had the MMR. Vaccination records back in the day were typically on paper (mine were from the early 1970s) and unable to be tracked if your clinic closed and paperwork is gone. I hope that helps!
Respectfully, Dr. Bernard I am aware of what you outlined & apology for not be clearer in my question or concern for what I believe is the majority of not a large percentage of newborns are susceptible to contracting measles.
The conventionsl paradigm being babies born to mother's who have developed measles antibodies from natural exposure or vaccination are protected throughout their initial "12 months" is flawed if I understand correctly from what I have read.
These passive antibodies wane significantly during the initial post partum period such that their is limited protection after 3-6 months.
If my understanding is correct (stand corrected) newborns would have little to no competing maternal antibodies post 6 months from delivery. Once again if this has been established should we not be evaluating when the recommended 1st dose of MMR should be offered/administered. This would then not be considered MMR0.
Appreciatively yours,
John