#12,734
Two months ago, shortly after the first outbreaks of H5N8 were reported in South Africa, government officials quickly decided to Reject Vaccination to Control Bird Flu - opting instead to go with quarantine and culling - a policy long recommended by the OIE.
As we've discussed often in the past, poultry vaccination brings with it a new set of problems, and can sometimes make a country's avian flu situation worse (see MPR: Poultry AI Vaccines Are Not A `Cure-all’ & New Scientist: The Downsides To Using HPAI Poultry Vaccines).As the virus has spread, and losses have mounted, there has been increasing pressure from the poultry sector for the South African government to approve the use of vaccines. Last week the headlines read:
Task team to look at vaccination against Avian Flu
By Sonja Raasch
August 25, 2017
Agriculture Minister Senzeni Zokwana has met with CEOs and senior managers in the poultry industry in a closed meeting to find solutions and discuss mitigation strategies to the current Avian Influenza outbreak.
In a statement, the department said the current outbreak was threatening the existence of South African Poultry industry as well as jobs in the sector.
The industry raised concerns on compensation and guidelines relating to the principles and guidelines of compensating affected farms. Another area of concern was vaccination of poultry against Avian Influenza. Industry also requested to be given permission to import fertile eggs to close the gap as a result of culled birds. (Continue . . . .)
These reports apparently raised hopes that approval was imminent, an expectation the Agriculture Department today appears to be trying roll back. Overnight a number of `cautious' statements on poultry vaccines have been published in South African media.
Agriculture Dept urges caution on vaccination against avian flu
As farmers grapple with the highly pathogenic outbreak of the H5N8 strain, the sector wants government’s approval to vaccinate.
CAPE TOWN - The Agriculture Department says farmers have to be cautious about vaccinating against avian flu because past experience has shown there are repercussions for the poultry industry.
As farmers grapple with the highly pathogenic outbreak of the H5N8 strain, the sector wants government’s approval to vaccinate.
(SNIP)
Maja says this time around, they need to be careful about rushing to vaccinate.
“There are certain vaccines available, globally, but none registered for use in the country.”
(Continue . . . )
'Bird flu vaccine would have to be based on sound scientific research'
Thousands of chickens have been culled and their eggs destroyed. Ostriches and other birds are also affected.
Rahima Essop | about 19 hours ago
CAPE TOWN - Agriculture Minister Senzeni Zokwana says 24 outbreaks of Avian Flu have been detected since a recent outbreak of the disease in June. (SNIP)
Desperate for a solution, the poultry industry wants government to roll out a vaccine for the highly pathogenic H5 N8 strain.
But Minister Zokwana says such a decision would have to be based on sound scientific research.
“It is the decision that is to be based on scientific research for the long-term benefit of the sector and the country.”
The Agriculture Department's Doctor Mpho Maja says there are serious risks associated with vaccines.
“There are too many repercussions to vaccines that we would not take the decision lightly.”
(Continue . . . )
The handful of countries (primarily China, Egypt, Vietnam & Indonesia) that elected to go down the poultry vaccination road a dozen years ago - instead of aggressive quarantine and culling - are still battling avian flu.
While vaccines can often protect poultry against illness - they don't necessarily prevent infection - resulting in subclinical `stealth' infections can spread unnoticed. Poorly matched or improperly administered vaccines can actually drive the evolution of `vaccine escape' variants, which increases viral diversity and further diminishes the vaccines effectiveness.
The HPAI Poultry Vaccine Dilemma
Study: Recombinant H5N2 Avian Influenza Virus Strains In Vaccinated ChickensEID Journal: Subclinical HPAI In Vaccinated Poultry – China
Lastly, vaccinated poultry may not be readily accepted by foreign markets, since it hinders testing for the virus. This could cause a greater economic loss for some countries than the virus itself.
While many countries remain staunchly resistant to the use of poultry AI vaccines - particularly across the EU and in North America - should avian flu viruses continue to proliferate at the rate we've been seeing over the past couple of years, this is a debate that we could see raised more often.Meanwhile, China - which is arguably too dependent upon poultry vaccines to change policies now - decided to roll out a new combination HPAI H5 + H7 vaccine this summer (see China MOA Orders HPAI H7N9 Vaccine Deployed Nationwide This Fall) in hopes that it will help curb their rapidly evolving H7N9 virus, as well as reining in their growing number of HPAI H5 viruses.
For more on the potential unintended consequences of poultry AI vaccination, you may wish to revisit:
Virology: Selection Of Antigenic Variants Of An H5N1 HPAI Virus In Vaccinated Chickens
Taiwan COA Warns Against Importation & Use Of AI Vaccines
Subclinical Highly Pathogenic Avian Influenza Virus Infection among Vaccinated Chickens, China).
