A report from India of apparent failure of rabies post-exposure prophylaxis raises a significant concern. Few details are available, but it is reported that the affected person is currently in a coma, and if that is the case, death is almost certain. This case requires careful investigation, given the almost invariably fatal nature of rabies and the assumption that proper post-exposure treatment is basically 100% effective.
From my standpoint, I’d want to confirm that:
- the person actually completed the proper treatment course (one dose of anti-rabies antibodies and a series of four rabies vaccinations over a few weeks) – the article says the course was completed but doesn’t give details of what that entailed.
- proper antibody and vaccine were used.
- correct doses were administered.
- the antibody and vaccines had been handled properly (e.g. kept at required temperatures – which at times may be easier said than done in a country as hot as India).
If all of these factors are confirmed, I’d want to know whether the person had some other disease or a compromised immune system that might have prevented him/her from responding properly to vaccination.
If no underlying problem was present, I’d want to see some testing of the lots of antibody and vaccine that were administered to ensure that they were adequate.
The timeline from when the person was exposed to when he/she received the post-exposure treatment to when he/she developed clinical signs of rabies is also critical. Delaying treatment for too long can also result in treatment failure.
Undertaking such an investigation is very important because the cause for any treatment failure needs to be understood if at all possible to help prevent it from happening again.
In the same news article, another man is also reported to be in a coma due to rabies infection, because he failed to complete the full course of treatment. That’s a more common problem and can be caused by lack of awareness of the importance of completing the full treatment course, inadequate communication with healthcare providers and, in some regions, shortage of vaccine.
These cases show that while post-exposure treatment is a critical aspect of rabies prevention, it shouldn’t be relied on as the sole line of defense. Feral dog control, rabies vaccination of animals and education regarding bite avoidance are critical rabies-control measures that often get ignored.