The company said that the first data from clinical trials show an increase in the level of antibodies after the third vaccination.
The pharmaceutical company Pfizer said that it intends to seek approval from the US federal authorities for the third dose of its COVID-19 vaccine.
The company said that another vaccination can significantly increase immunity and help protect against new dangerous strains of coronavirus.
Studies conducted in many countries show that widely used COVID-19 vaccines provide reliable protection against the highly contagious delta strain.
But the antibodies that neutralize the virus naturally weaken.
Pfizer said that preliminary data from clinical trials show that the level of antibodies in people increases after the third dose is administered.
Submitting an application does not mean that the third dose of vaccination will be applied in the near future. The health authorities should decide whether they are necessary.