- There were rumors last year that CDC officials had recommended mothers delay breastfeeding their babies to allow vaccinations to work better.
- The rumors were traced back to a study funded by the agency.
- The study’s findings were incorrectly interpreted by some bloggers, resulting in perpetuation of a fake news campaign.
In early 2015, rumors were circulating on various Internet blogs that the U.S. Centers for Disease Control and Prevention (CDC) was recommending that mothers should delay breastfeeding their babies to boost vaccine efficacy.1 2 The recommendations were traced back to a 2010 study funded by CDC and published in The Pediatric Infectious Disease Journal.
The study examined the inhibitory effect of breast milk on infectivity of live oral rotavirus vaccines in poor nations versus industrialized nations.3
Interestingly, when you take close look at the study itself and compare its findings with those publicized on some blogs it is clear that the content of the study has been misinterpreted and overly generalized. For this reason, it is important to always refer to original sources of published information, particularly when it relates to health issues that may affect you and your family.
Although blogging serves its own purpose in the world of information sharing, blogs are often informal, opinionated pieces of information that frequently fail to include original references to allow independent fact-checking by readers. In fact, much of the information published on the Internet is not referenced, resulting in false assumptions, misinterpretation, fabrication and generalizations on many topics, including vaccines and infectious diseases. Looking to see whether original sources are cited by bloggers and engaging in fact checking is the best way to detect fake news.
There are several clarifications on the breastfeeding study’s findings that dispel the rumor that the CDC was indeed recommending delaying breastfeeding during the time when babies are being vaccinated. First of all, it is true that the study was funded by the CDC, but there were no formal statements made by the CDC officials in the study nor posted on the agency’s website regarding delaying or stopping breastfeeding during vaccination of babies.3 4
The study specifically examined one vaccine: the live oral rotavirus vaccine.3 Many blogs inferred that the CDC was recommending that mothers “stop breastfeeding to boost vaccine efficacy.” This kind of messaging influenced the reader to believe that the CDC’s recommendation—which was false to begin with—applied to all vaccines.3 5
The following is a brief background on the goal of the breastfeeding study, according to the authors:
Live oral rotavirus vaccines have been less immunogenic and efficacious among children in poor developing countries compared with middle income and industrialized countries for reasons that are not yet completely understood. We assessed whether the neutralizing activity of breast milk could lower the titer of vaccine virus and explain this difference in vitro.3
In essence, the researchers were perplexed that the live oral rotavirus vaccine tends to fail more often in infants living in poor countries, despite the fact that mothers in low-income countries have high anti-rotavirus IgA titers in their breast milk.3 As a result, they decided to look into whether the neutralizing effect of breast milk was lowering the titer of the vaccine virus.3
Also, breast milk samples were collected from mothers in four countries: India, Vietnam, South Korea and United States. Mothers in India had had highest titers against all three rotavirus vaccine strains, while American women had the lowest titers.3 The following is the study authors’ interpretation of their findings [bolded text is not study authors’ but is provided here for clarification]:
The lower immunogenicity and efficacy of rotavirus vaccines in poor developing countries could be explained, in part, by higher titers of IgA and neutralizing activity in breast milk consumed by their infants at the time of immunization that could effectively reduce the potency of the vaccine. Strategies to overcome this negative effect, such as delaying breastfeeding at the time of immunization, should be evaluated. These data should encourage clinical trials to investigate whether delaying breast-feeding for a short period before and after giving the vaccine could reasonably improve the immune response and protective efficacy.”3
Careful reading of the study and its findings clearly indicates that neither the study authors nor the CDC made a recommendation for mothers to stop breastfeeding during rotavirus vaccination, they were simply investigating an hypothesis and presenting limited evidence as a starting point for further investigation. Although there have been instances when public health officials have accurately accused of participating in fake news of their own—such as when they maximize the risks of infectious diseases and minimize the risks of vaccination—distorting the truth is not right, no matter who is doing it.
There is a lesson in this story about the fake news created around breastfeeding and vaccination: It is a good idea to fact check and refer back to the original source of information published on the Internet to verify and put it into perspective before you pass it on. It’s the best way to detect and put fake news—of all kinds—out of business
1 Global Freedom Movement. CDC Recommends Mothers to Stop Breastfeeding to Boost Vaccine Efficacy. Global Freedom Movement Jan. 14, 2015.
2 Michaelis K. CDC Advises Delayed Breastfeeding to Boost Vaccine Efficacy. Foodrenedage.com.
3 Moon S-S, Wang Y, Shane AL, et al. Inhibitory Effect of Breast Milk on Infectivity of Live Oral Rotavirus Vaccines. The Pediatric Infectious Disease Journal 2010; 29(10): 919-923.
4 Centers for Disease Control and Prevention. Breastfeeding Guidelines and Recommendations. CDC.gov Dec. 18, 2015.
5 Pond M. The CDC Says to Stop Breastfeeding my Baby to Boost Vaccine Effectiveness—NOT TRUE! Vaxtruth.org Jan. 24, 2012.