H5N1 virus has been transformed ... the current vaccine has no effect?

Scientists once claimed that the bird flu virus only appeared in the winter. However, this year, the flu appears again on hot summer days. Regarding this unusual change, Dr. Nguyen Tien Dung - Head of the Department of Viruses (Veterinary Institute) said:

Viruses in general, H5N1 viruses in particular are always changing. In Vietnam, the H5N1 virus has also changed and changed continuously. At first, the world recommended that based on the H5N1 strain of virus appear in Vietnam to produce human vaccines, after that, due to the virus mutation, it was recommended to produce vaccine based on H5N1 virus characteristics in Indonesia. then China .

Does this affect the production of vaccines for humans, sir?

Currently, the world has not been able to agree on the virus strains in any country to produce vaccines against pandemics. In our country too, we only produce pre-pandemic vaccines.

What is special about the strain of H5N1 virus in Vietnam?

(Photo: VNN)

When the epidemic first appeared (December 2003), the H5N1 virus only had genotype (phenotype) Z. However, since 2005, we have discovered G genotype, similar to the genotype that appears in Quang region. West and Hunan (China). The rate of variation of H5N1 virus is quite large: 1 / 1,000, ie on average, in 1,000 individuals, there is 1 individual mutation at random.

Fortunately, not all mutants can survive. From the emergence of G genotype, we can confirm that the G-type virus invaded from Guangxi and Hunan (China) regions, mainly according to smuggled poultry. The virus has also changed by region: In the South, the virus forms a separate group and is different from the virus group circulating in the North.

Does that mean that the vaccine we are using for chickens and ducks today will not work with G genotype?

The vaccine we are using is based on genotype Z. Between Z and G types, the similarity is quite low, so when vaccination is based on Z genotype, the possibility of the H5N1 genotype virus is still high. .

Many concerns about this year's bird flu recurrence 'unseasonal'. Do you have any comments on this issue?

Following the evolution of the epidemic, the scientists found that the countries of the Northern Hemisphere often appear in the winter; and countries in the Southern hemisphere often translate in the summer. However, that is only normal, not necessarily happening. The main reason is that vaccination is neglected, then injected, improperly injected .

Even when vaccinated, many people subjectively assumed that the epidemic would not play, so they did not implement other biosecurity measures, such as strict control of transporting, trading and slaughtering; not rearing between waterfowl and poultry; not poisoning, disinfection .

It should be noted that vaccination is only meant to limit the development of the virus, not to kill the virus. When vaccinated, the virus still exists in the herd, so when the vaccination is not done properly, on time, in the right way and does not apply other measures, the virus will develop and become an outbreak immediately.