Another New Vaccine

Efficacy. Herd immunity. Mutations. Clinical trials. I've never seen more people pay more attention to vaccine science than with Covid. Less noticed is another important new vaccine, long after Jonas Salk and Albert Sabin developed the first polio vaccinations.

No vaccine is perfect. Poliovirus won’t paralyze you if you’ve had your Salk shots, but it can still pass from your gut to paralyze someone else—much as my Covid vaccination may still let me infect you. Sabin’s polio vaccine, taken by mouth, avoids this by destroying poliovirus in the gut. Where vaccination rates are low, though, harmless live virus from the vaccine can pass from person to person long enough to mutate and do harm—much as coronavirus mutates into new strains in the absence of herd immunity.

Hence the excitement about nOPV2, the novel oral polio vaccine type 2 set for use in 2021. It offers the best of both worlds, targeted to virus in the gut and genetically modified to avoid mutation. It may help end polio once and for all.

Image: Participants in an nOPV2 clinical trial lived four weeks in Poliopolis, a container village in Belgium. Photo credit: Ananda Bandyopadhyay, Bill & Melinda Gates Foundation