Pfizer said a third dose of vaccine could prevent Omicron infection

In December 8th, Pfizer’s official website issued a statement saying that the third dose of the new crown vaccine BNT162b2 is expected to fight COVID-19 Omicron variant infection. Its targeted neutralizing antibody is 25 times higher than that of two doses of vaccine.

Omicron infection

On December 7, the African Institute of health released information that the neutralizing antibody titer against Omicron variant in two doses of Pfizer vaccine was 41 times lower than that of the original strain, which attracted global attention. Pfizer released similar data the next day, saying that the antibody titer decreased 25 times, and two doses of vaccine may not be enough to prevent Omicron infection. However, most epitopes targeted by vaccine induced T cells are not affected by spike protein mutation. Therefore, it is speculated that vaccination still has a protective effect on severe infection, and the real-world data for Omicron need to be continuously monitored worldwide.

Pfizer said the third dose of vaccine may have stronger resistance to Omicron. The latest test showed that the serum antibody titer against Omicron increased 25 times after the third dose, which was equivalent to the previous levels of various variants of the two doses of vaccine. The third dose of vaccine also strongly increased the level of immune CD8 + T cells targeting a variety of coronavirus spike protein epitopes, while most epitopes contained in Omicron did not change, which may also have a stronger protective effect.


Albert bourla, chairman and CEO of Pfizer, believes that the two doses of vaccine can provide prevention against severe infection of Omicron, and the effect is better after the third dose. It is the best way to prevent the spread of COVID-19 by ensuring that as many people as possible complete two doses of vaccination and third doses of vaccine. If it is confirmed that the vaccine adaptation needs to be adjusted to cope with Omicron, Pfizer can produce the first batch of new vaccines for approval within 100 days and deliver them in March next year.

Dr. Ugur Sahin, CEO of biontech, also said that the two companies are developing corresponding vaccines, which will produce a higher level of protection against Omicron. Although a new vaccine will be delivered soon, people who are eligible for vaccination should be vaccinated as soon as possible to establish the risk of various COVID-19 variants.

reference material:

  1. pfizer



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