What do you mean by four prices?

Trivalent and tetravalent vaccines are mainly antiviral drugs.

Influenza is the abbreviation of influenza, which is mainly caused by influenza A (a) and B (b) viruses. Because the virus often mutates its antigen, it is highly contagious and spreads quickly, and it is prone to widespread epidemic. Especially for infants, the elderly and patients with basic heart and lung diseases, influenza virus infection may be complicated with serious complications such as pneumonia, leading to serious illness or death.

Influenza vaccines supplied in autumn are trivalent inactivated influenza vaccine (IIV3) and tetravalent inactivated influenza vaccine (IIV4). Trivalent vaccine includes three virus types: H 1N 1, H3N2 and Victoria strain B; On this basis, the tetravalent vaccine also contains Yamagata type B influenza virus.

The public can voluntarily vaccinate any kind of influenza vaccine, and there is no priority recommendation. Both vaccines have preventive effects on viruses A (H 1N 1), H3N2 and B (Victoria), while tetravalent vaccines mostly prevent influenza B. From the price point of view, trivalent vaccine is lower in price and relatively high in cost performance.

Although there are differences in the types of viruses targeted, the Technical Guidelines for Influenza Vaccination in China (20 18-20 19) points out that the immune response of trivalent vaccine is similar to that of tetravalent vaccine.