Newcastle Disease (Hansard, 16 December 1970)

§ Mr. Prior

The serious epidemic situation demands an urgent decision on the possible use of live Newcastle disease vaccine. Live vaccine is cheaper to make and administer than the inactivated vaccine, so its use can be expected to improve the general level of protection in the industry. Overseas experience has indicated that it can also give marginally better protection to very young birds. But 377W there have been serious doubts on veterinary and administrative grounds about its use in the conditions experienced in this country.

In order to form judgments on the veterinary aspects the Secretary of State for Scotland and I recently authorised urgent field trials of Hitchener B1 vaccine on selected poultry units. Sufficient evidence is now available from these trials to suggest that there should be no significant side-effects when the vaccine is used on chicks 10–14 days old, while on day old chicks there should be only a mild respiratory effect of short duration. This effect is, however, somewhat increased when the vaccine is administered at the same time as live infectious bronchitis vaccine. The evidence so far obtained supports the view that the live vaccine may give some degree of protection to very young birds.

On the administrative side, the use of live vaccine may slightly interfere with our diagnostic tests and control measures but it should be possible to maintain a modified form of notification and most of the present control measures.

The Secretary of State and I are satisfied therefore that there would be a significant balance of advantage in approving live vaccines of the Hitchener B1 strain for general use and we propose to do so forthwith. We hope that supplies will start to become available within the next two to three weeks.

There remains a very strong case for the continued use of the inactivated vaccine on all birds in disease-free areas, where immunity would have time to develop before challenge, and on growing and adult birds in all areas which have already been vaccinated, whether with live or inactivated vaccine. Our veterinary advisers will be advising producers accordingly.

The existing veterinary controls on imports have the effect of excluding poultry and poultry carcases from most countries. Although this has not been their purpose, they have thus had the incidental effect of protecting producers in this country from the major fluctuations in supply and prices which occur from time to time in world markets. Once live vaccine is effectively in general use, the present veterinary controls on imports 378W will no longer be required. But the Government recognises that, when that time comes, it will be necessary to make arrangements to prevent the home market from being undermined by unduly low-priced imports. The Government will be consulting with domestic and overseas interests on the nature of the arrangements required.

In relation to Scotland, my right hon. Friend and I will be reviewing, in consultation with the industry, the policy of slaughter and compensation which at present operates there.