There is vaccine to prevent COVID-19 infection.

and infants should be given following vaccine : ______________________ A. Hepatitis A & B vaccine B. Hib vaccine C. HPV vaccine D. TDAP vaccine 请排序，例：ABCD

A、Inactivated vaccine

B、Subunit vaccine

C、Nucleic acid vaccine

D、Subunit vaccine

DNA疫苗(DNA vaccine)(名词解释)

What step is essential to the traditional production of flu vaccine？

[A] Manufacturers implant the vaccine into ordered chicken eggs.

[B] Scientists identify the exact strain soon after a flu pandemic starts.

[C] Public health measures are taken as an important pandemic-fighting tool.

[D] Viruses are deadened and made clean before being put into vaccine use.

核酸疫苗(nucleic acid vaccine)

亚单位疫苗(subunit vaccine)(名词解释)

ry year in order to

A．provide a good match between the vaccine and the virus strains

B．save the expense in producing and distributing the vaccine

C．reduce the frequency the flu viruses change from one strain to another

D．leave time to manufacture and distribute vaccines before the flu season