In an earlier newsletter, I promised to tell you about some interesting news on the effectiveness of the I‑2 Newcastle disease vaccine compared with other 'commercial' vaccines in village poultry. The data come from a survey of village chickens in 5 different districts in Malawi, conducted last year by staff of the Central Veterinary Laboratory (CVL).
We've always known that many of the commercial vaccines just do not cut it in the village. That's not criticism - they work well under commercial conditions where chickens are under good control. But for free range chickens in the village, we've seen lots of failures. Indeed, that was precisely the reason the thermotolerant vaccines such as I‑2 were developed way back - to effectively protect village chickens.
So the CVL team measured the level of immunity in chickens vaccinated with I‑2 and chickens vaccinated with other Newcastle disease vaccines. They found quite a difference. Among 123 chickens vaccinated with I‑2, 89% had immunity levels adequate to protect them in the face of an outbreak. However, among 92 chickens vaccinated with other Newcastle disease vaccines, only 25% were found to have adequate immunity levels.
For sure, these results did not surprise us. They were quite consistent with our field observations. But it's always rewarding to see your world view supported by some independent evidence.And before I go: Don't forget our Chickens for Change photography competition. We would love to have your entries!
Enough for now. I'll be in touch again soon.
3 June 2021