Wednesday, June 14, 2017

China To Test New H7N9 Poultry Vaccine In Two Provinces


While the number of human infections with H7N9 are on the decline across China, two new strains of the virus have emerged this winter, and are spreading across the landscape; an HPAI (highly pathogenic) version, and a new Yangtze River Delta lineage.
Last March, in WHO: Candidate Vaccines For Pandemic Preparedness, plans were announced for the development of a new candidate vaccine virus (CVV) for human use. 
Around the same time, China announced plans to upgrade their existing H5 poultry vaccine to deal with these newly evolved H7N9 avian viruses. While most countries eschew the use of poultry AI vaccines, since 2005 China has relied heavily on avian vaccines to try to control their bird flu outbreaks. 
According to 2012’s Impact of vaccines and vaccination on global control of avian influenza by David Swayne, China uses nearly 91% of the world's poultry avian flu vaccine, followed by Egypt (4.6%).
While it can be argued that these vaccines have saved tens of millions of poultry from culling, have prevented financial ruin for farmers, and has lessened food instability in developing areas of the world, they are not without some downsides. 
First, poultry vaccines don’t always prevent disease – sometimes they only mask the symptoms of infection.  That can not only allow viruses to spread stealthily, it can also put human health at risk (see Zhong Nanshan's 2009 comments in Chinese expert issues new bird flu warning).
And secondly, the use of poorly matched or improperly administered vaccines has been linked to the spread and evolution of `vaccine escape' viruses (see cites below), which may account for some of the past decade's growing diversity of avian influenza in China.
The HPAI Poultry Vaccine Dilemma
Study: Recombinant H5N2 Avian Influenza Virus Strains In Vaccinated Chickens
EID Journal: Subclinical HPAI In Vaccinated Poultry – China
Given the endemicity of a growing number of dangerous bird flu viruses (H5N1, H5N6, H5N8, H7N9, etc), and their huge reliance on their poultry industry to provide enough food to feed a billion plus people, China at this point has few options beyond using vaccines.

While I've not found the official announcement, the Chinese press overnight has quoted the MOA as stating a new combination H5N1/H7N9 vaccine will be rolled out for testing this summer in two provinces; Guangdong and Guangxi.

First this report from the English language edition of China Daily. 

Vaccine to be tested

By Wang Xiaodong | China Daily | Updated: 2017-06-14 07:33
Poultry in two southern regions will begin receiving the first vaccine against the H7N9 bird flu virus early next month, as authorities look to control the spread of the potentially fatal disease. 

Guangdong province and the Guangxi Zhuang autonomous region have been chosen to test the new vaccine, as both are major centers of the poultry trade, according to the Ministry of Agriculture. 

Evidence also indicates the "existence of highly pathogenic and low pathogenic strains of the H7N9 virus" in these areas, the authorities said.The vaccine, developed by the Chinese Academy of Agricultural Sciences' Harbin Veterinary Research Institute, will be given to all chickens, ducks and geese. 

(Continue . . . )
We get a far more detailed (translated) description of this new vaccine from the Chinese farm market press.

Guangdong and Guangxi take the lead in the implementation H7N9 immunization or early July start

Published: 2017-06-14 08:28:18

  Recently, the Ministry of Agriculture decided to carry out the first H7N9 immunization in Guangdong Province and Guangxi Zhuang Autonomous Region. The vaccine according to the security situation, in principle, to start in early July immunization.


  The vaccine is a recombinant avian influenza virus (H5 + H7) bivalent inactivated vaccine (H5N1 Re-8 strain, H7N9 H7-Re1 strain) vaccine R & D units selected by the designated production enterprises, according to the production requirements of the emergency after inspection, vaccine supply and lot release simultaneously. Chinese Veterinary Drug Control urgently batch release. The vaccine according to the security situation, in principle, to start in early July immunization.

  Immunization coverage

  Various poultry in Guangdong, Guangxi chickens, ducks, geese and other full implementation.

  Immunization program:

  Laying hens, chicken, duck, duck, goose eggs, goose and chicken growth over 70 days twice a centralized implementation of immunization, immunized twice the interval of 3-4 weeks. After concentrated immunization, according to the immunization program for immunization.

  GROWING less than 70 days to conduct a centralized poultry immunization.

  Bivalent vaccine will replace the existing H5 vaccine to achieve full protection

  The recombinant avian influenza virus (H5 + H7) bivalent inactivated vaccine (H5N1 Re-8 strain, H7N9 H7-Re1 strain) can simultaneously achieve protection of the H5 and H7 subtypes of avian influenza.

(Continue . . . .)
There is little doubt that the events of this 5th winter wave of H7N9 has Chinese officials worried - not only over the potential impact to their poultry industry - but over pandemic prospects as well.
For the past few years, the Chinese media has vigorously downplayed the risk of H7N9 becoming a pandemic, pointing out that the virus does not transmit easily between humans. 
But overnight China Daily - citing a recent study in The Lancet - published an uncharacteristically blunt warning.

'Pandemic' possible with H7N9 virus
By Shan Juan | China Daily | Updated: 2017-06-14 07:33
Mutations could lead to worldwide catastrophe, Chinese study finds 

A study published by a prestigious international medical journal has warned that mutations in the bird flu H7N9 virus could lead to a "pandemic" that could cause sickness and death around the world. 

The study, led by Yu Hongjie and fellow researchers at Fudan University's Public Health Institute in Shanghai, is based on information from all lab-confirmed human cases of H7N9 reported in the Chinese mainland as of late February.
         (Continue . . . )

This English language article joins last April's NPR: A Pessimistic Guan Yi On H7N9's Evolution, in expressing grave concerns over the recent evolution and path of H7N9. The CDC's Updated Risk Assessment On China's H7N9 Virus, released last March, states:
Asian lineage H7N9 virus is rated by the Influenza Risk Assessment Tool (IRAT) as having the greatest potential to cause a pandemic, as well as potentially posing the greatest risk to severely impact public health.  

All of which means a lot may be riding on the successful deployment and ultimate impact of this new H5 + H7 avian flu vaccine.