The Common Marmoset in Research

Mike Ryan, November 9, 2018

As a followup to our previous post about common marmosets, we’ll now take a look at how often they’re used in research, why they’re used, and which parts of the National Institutes of Health (NIH) have most readily ignored federal law with regards to the need to “replace, reduce, and refine” experimentation on animals. Here’s the current state of play:

1,175 used from 2013-2017

In contrast to rhesus macaques, which are used in 65% of primate testing in the U.S., common marmosets are used only about 3% of the time according to NIH data. Overall, 1,175 common marmosets were used in NIH-funded grants and cooperative agreements awarded from 2013-2017. It’s unclear how many of them were used for Category E experiments (meaning significant pain is inflicted on them while they’re caged, with no pain relief). More females than males are used in these experiments by a 56% to 44% margin.

NIA leads NIH in common marmoset experiments

NIH has made repeated assurances to members of Congress that they’re working to accommodate federal law with regard to the “three Rs” (replace, reduce, refine), but that message clearly hasn’t been heard by the National Institute on Aging (NIA), which leads NIH in terms of common marmoset experiments. The NIA, led by Director Richard Hodes, used 306 common marmosets in experiments from 2013-2017.

Primate experimenters want more of them

As reported in Science magazine October 2018, experimenters in the U.S. now want to use more of these primates than they can get their hands on. This is despite repeated NIH assurances to Congress that NIH is working to reduce the number of primates that suffer in captive medical experiments.

Importation, domestic breeding

Yes, common marmosets are found in Brazil (and elsewhere in various northern and middle areas of South America), but an international agreement prevents their export. Records show that 249 common marmosets were imported to the US in 2017 for experiments. That number would be higher if most airlines weren’t exercising their right not to ship these animals given public opposition to the use of primates in medical testing. In the U.S., there are 3 top breeders of common marmosets, and they’re NIH-supported. They are Southwest National Primate Research Center, Wisconsin National Primate Research Center, and Johns Hopkins University.

Next, read why we need to push the “monkey model” out and embrace alternatives.