The World Organisation for Animal Health (WOAH) says more testing of African swine fever (ASF) vaccines is needed, according to a Reuters report.
The warning comes as Vietnam plans to export doses of ASF vaccines to other countries in the coming months.
The world’s first ASF vaccines were authorized by Vietnam in July, when two vaccines were cleared for domestic use in pigs in the country. Approval came after widespread testing in the country’s swine herds. The government reported the vaccines to be 95% effective. The vaccines – NAVET-ASFVAC (from Navetco National Veterinary Joint Stock Co.), and the AVAC ASF LIVE vaccine (from AVAC) — were jointly developed by U.S. scientists with two different commercial partners in Vietnam. In some other Asian countries, registration of the AVAC vaccine is underway. A third vaccine, DACOVAC-ASF2 vaccine from the Dabaco Group, is reportedly under evaluation in Vietnam.
WOAH says AVAC Vietnam JSC, the producer of one of the vaccines, has not shared sufficient data with international researchers and bodies, Reuters said. Gregorio Torres, head of the science department at WOAH, urged countries interested in using AVAC's vaccines to conduct their own trials before approving it.
In October, WOAH warned veterinary authorities and the global pig industry against the use of non-compliant and poor-quality vaccines for ASF. In a statement issued October 18, WOAH stressed the importance of the use of only high-quality ASF vaccines with proven efficacy and safety, and which have been subject to regulatory evaluation and approval in accordance with WOAH international standards.
"If somebody puts in the market a vaccine which is suboptimal, it will impact everybody," Torres told Reuters, noting that it is harder to assess vaccines in countries with ongoing epidemics, such as Vietnam, because pigs could be infected by the attenuated virus in the vaccine alongside the wild virus.
In the Philippines, applications are under consideration for the importation of four ASF vaccines. A Phase 1 trial was completed in May, and three farms in different provinces have been selected as the locations of Phase 2 field trials, the source reports. Authorities are awaiting complete documentation from a second vaccine company. In order to bring to an end the country’s four-year battle to eliminate ASF, the government has allocated PHP1.5 billion (US$26.4 million) for the vaccination of the nation’s hogs.
Convinced of the added value that the international recognition of high-quality vaccines would have, WOAH is monitoring the progress of several ASF vaccine candidates at various stages of development. Some countries have either approved or are conducting field trials for the use of modified live vaccine candidates against ASF genotype II.
A new draft standard for the production of safe and effective vaccines against ASF was proposed in the September report of the WOAH Biological Standards Commission. WOAH urges vaccine manufacturers and members to consider these draft standards when developing and evaluating ASF vaccine candidates for regulatory approval and to provide their comments.
