Any new information on peanut vaccines?
Actually yes; and it seems to be very promising news. As you may recall from previous articles in this newsletter, the one FDA approved oral peanut vaccine is less than ideal: it causes a lot of side effects including occasional anaphylaxis and it confers very modest protection. But, a breath of fresh air came to peanut vaccine research based on astute observation by immunologists at Boston Children’s Hospital. They discovered a major difference in the stool microbiome of children with food allergies versus those without.
The non-allergic children had two “protective” bacteria Subdoligranulum variable and Clostridia species. Based on this discovery they did experiments in mice who were peanut allergic. Transferring these bacteria to the mice stopped the anaphylaxis they would otherwise have if given peanut. As it turns out the healthy bacteria stimulated a subset of immune cells called regulatory T cells (Treg’s). The Treg’s protect against allergic reactions.
With this exciting result they have moved forward to small clinical trials in children. (“small” in terms of number of participants, not because of the size of the patients). By adding the bacteria to the peanut protein in the oral peanut vaccine the patients did not experience allergic reactions from the vaccine and they developed good protective response.
In a second phase of the study, they gave a brief course of oral antibiotics targeted to killing bad colon bacteria and then the oral vaccine. This group had an even better protective response. The only bad news in all of this is that the Boston researchers couldn’t refrain from referring to their new vaccine as “Poop Pills”.