Home
Neonatal Vitamin A Supplementation May Negatively Affect Response to Pediatric Vaccination
Bob Roehr
April 30, 2010 (Bethesda, Maryland) — Routine pediatric vaccination and vitamin A supplementation in low-income countries where deficiency is common are both good medical practices, but the 2 together might result in suboptimal immunization levels in infants.
This counterintuitive finding was presented at a late-breaker session here at the National Foundation for Infectious Diseases 13th Annual Conference on Vaccine Research by Danish researcher Christine S. Benn, MD, PhD, from Bandim Health Project, Statens Serum Institut, Copenhagen,. Because volcanic ash from Iceland shut down European airspace, canceling her flight, she delivered the findings by telephone link.
Separate randomized controlled neonatal trials, conducted in Guinea-Bissau, West Africa, of normal- and low-birth-weight infants found "there was no overall effect of vitamin A" supplementation and early childhood vaccination in terms of mortality, she said.
"But when we stratified the data by sex, vitamin A was associated with a slightly nonsignificant beneficial effect in boys, and the opposite in girls, compared with placebo." Combined mortality rate ratio for boys was 0.80 (95% confidence interval [CI], 0.58 - 1.10), and for girls was 1.41 (95% CI, 1.04 - 1.90).
Dr. Benn said that "the excess female mortality after vitamin A was particularly pronounced when DTP (diphtheria-tetanus-pertussis) vaccine was the most recent vaccine."
Six previous studies had reached conflicting conclusions about whether or not vitamin A supplementation was beneficial.
The 3 that found it beneficial exhibited initially high infant mortality rates and had lower rates of early vaccination. Infant mortality dropped after the first few months.
The trials that found no benefit with vitamin A supplementation exhibited high infant mortality throughout the first year of life, and had higher rates of infant vaccination during this period.
"Our interpretation of the data is that vitamin A may be beneficial during the first month of life, but the effect may shift when the children receive DTP," Dr. Benn said.
Throwing vaccination for measles into the mix produced even more complex vitamin A and mortality outcomes. If girls received DTP at 3 to 4 months as their last vaccination, they had higher mortality than boys, until vaccination for measles at 8 to 9 months, which seemed to rescue them but did not correct for the earlier surplus mortality.
Dr. Benn explained that "from 4 to 36 months, girls receiving measles vaccination was associated with 2.5 times higher mortality than placebo." She speculated that "the multitude of vaccines and vitamin A overloaded the immune system in some way."
"The data suggest that we may optimize the use of vitamin A supplementation if we take the sex differential, immunomodulatory effect, and interactions with vaccines into account."
Conference cochair Bruce G. Weniger, MD, from the Centers for Disease Control and Prevention's National Center for Immunization and Respiratory Diseases, called it, "a rather remarkable and important report — disconcerting, to be sure — about how we often don't think outside our own narrow field," be it nutrition or infectious disease.
He told Medscape Infectious Diseases that he did not believe that the findings are particularly relevant to a developed world setting. Vitamin A supplementation is common in formula and food given to infants in the United States and Europe, but at levels significantly lower than given through injection in the developing world.
Dr. Weniger saw problems of malnutrition and higher background rates of infectious disease as likely being important contributing factors to this study's findings.
Studies have found that lower, more frequent supplementation is more beneficial than using a smaller number of high-dose interventions, Dr. Benn told Medscape Infectious Diseases in an email exchange. "So the reason for the problem may well be the large dose."
"The underlying problem, in our opinion, is that the inactivated DTP vaccine has negative nonspecific effects in girls (i.e., it enhances their susceptibility to other infections)," although Dr. Benn acknowledged that this is highly controversial. "Micronutrient supplements, by optimizing the immune system in otherwise deficient girls, may enhance these negative nonspecific effects."
"It may be that DTP is bad for girls in high-income countries as well as in low-income countries. However, since most girls in high-income countries will have adequate nutritional status irrespective of supplementation, I doubt that interactions between vaccines and micronutrients will be relevant from a public health perspective in high-income countries," said Dr. Benn.
This research was conducted as part of a collaborative effort between health agencies of Denmark and Guinea-Bissau. Dr. Benn and Dr. Weniger have disclosed no relevant financial relationships.
National Foundation for Infectious Diseases (NFID) 13th Annual Conference on Vaccine Research: Abstract LB1. Presented April 27, 2010.
Medscape Medical News
2010 Medscape, LLC
Send press releases and comments to news@medscape.net.
Bob Roehr
April 30, 2010 (Bethesda, Maryland) — Routine pediatric vaccination and vitamin A supplementation in low-income countries where deficiency is common are both good medical practices, but the 2 together might result in suboptimal immunization levels in infants.
This counterintuitive finding was presented at a late-breaker session here at the National Foundation for Infectious Diseases 13th Annual Conference on Vaccine Research by Danish researcher Christine S. Benn, MD, PhD, from Bandim Health Project, Statens Serum Institut, Copenhagen,. Because volcanic ash from Iceland shut down European airspace, canceling her flight, she delivered the findings by telephone link.
Separate randomized controlled neonatal trials, conducted in Guinea-Bissau, West Africa, of normal- and low-birth-weight infants found "there was no overall effect of vitamin A" supplementation and early childhood vaccination in terms of mortality, she said.
"But when we stratified the data by sex, vitamin A was associated with a slightly nonsignificant beneficial effect in boys, and the opposite in girls, compared with placebo." Combined mortality rate ratio for boys was 0.80 (95% confidence interval [CI], 0.58 - 1.10), and for girls was 1.41 (95% CI, 1.04 - 1.90).
Dr. Benn said that "the excess female mortality after vitamin A was particularly pronounced when DTP (diphtheria-tetanus-pertussis) vaccine was the most recent vaccine."
Six previous studies had reached conflicting conclusions about whether or not vitamin A supplementation was beneficial.
The 3 that found it beneficial exhibited initially high infant mortality rates and had lower rates of early vaccination. Infant mortality dropped after the first few months.
The trials that found no benefit with vitamin A supplementation exhibited high infant mortality throughout the first year of life, and had higher rates of infant vaccination during this period.
"Our interpretation of the data is that vitamin A may be beneficial during the first month of life, but the effect may shift when the children receive DTP," Dr. Benn said.
Throwing vaccination for measles into the mix produced even more complex vitamin A and mortality outcomes. If girls received DTP at 3 to 4 months as their last vaccination, they had higher mortality than boys, until vaccination for measles at 8 to 9 months, which seemed to rescue them but did not correct for the earlier surplus mortality.
Dr. Benn explained that "from 4 to 36 months, girls receiving measles vaccination was associated with 2.5 times higher mortality than placebo." She speculated that "the multitude of vaccines and vitamin A overloaded the immune system in some way."
"The data suggest that we may optimize the use of vitamin A supplementation if we take the sex differential, immunomodulatory effect, and interactions with vaccines into account."
Conference cochair Bruce G. Weniger, MD, from the Centers for Disease Control and Prevention's National Center for Immunization and Respiratory Diseases, called it, "a rather remarkable and important report — disconcerting, to be sure — about how we often don't think outside our own narrow field," be it nutrition or infectious disease.
He told Medscape Infectious Diseases that he did not believe that the findings are particularly relevant to a developed world setting. Vitamin A supplementation is common in formula and food given to infants in the United States and Europe, but at levels significantly lower than given through injection in the developing world.
Dr. Weniger saw problems of malnutrition and higher background rates of infectious disease as likely being important contributing factors to this study's findings.
Studies have found that lower, more frequent supplementation is more beneficial than using a smaller number of high-dose interventions, Dr. Benn told Medscape Infectious Diseases in an email exchange. "So the reason for the problem may well be the large dose."
"The underlying problem, in our opinion, is that the inactivated DTP vaccine has negative nonspecific effects in girls (i.e., it enhances their susceptibility to other infections)," although Dr. Benn acknowledged that this is highly controversial. "Micronutrient supplements, by optimizing the immune system in otherwise deficient girls, may enhance these negative nonspecific effects."
"It may be that DTP is bad for girls in high-income countries as well as in low-income countries. However, since most girls in high-income countries will have adequate nutritional status irrespective of supplementation, I doubt that interactions between vaccines and micronutrients will be relevant from a public health perspective in high-income countries," said Dr. Benn.
This research was conducted as part of a collaborative effort between health agencies of Denmark and Guinea-Bissau. Dr. Benn and Dr. Weniger have disclosed no relevant financial relationships.
National Foundation for Infectious Diseases (NFID) 13th Annual Conference on Vaccine Research: Abstract LB1. Presented April 27, 2010.
Medscape Medical News
2010 Medscape, LLCSend press releases and comments to news@medscape.net.
» Video for our MPH colleagues. Must watch
» Salam
» Feeling Sad
» Look here. Its 2020 and this is what we found
» Sad News
» Pakistan Demographic Profile 2018
» Good evening all fellows
» Urdu Poetry