ASOURCE Navi

The booster vaccination for the Omicron strain of the new coronavirus started on September 20th. We will start with elderly people aged 60 and over, people aged 18 and over with underlying diseases, and medical workers who are subject to the fourth vaccination with conventional vaccines, and will expand the target group after October. We have summarized the effects, side effects, vaccination target and timing, etc. of the Omicron strain vaccine.

The Pfizer and Moderna vaccines for the Omicron strain are a mixture of components derived from the conventional strain (Wuhan strain, China) and components derived from the BA.1 of the Omicron strain that spread during the sixth wave. It corresponds to BA.1 and is expected to be effective against BA.5, which is currently in vogue.

The Omicron strain has mutated significantly from conventional new coronaviruses, making it difficult to prevent infection with conventional vaccines.

According to the clinical trial results of the Omicron strain vaccine, the neutralizing antibody that reacts to BA.1 and prevents infection is 1.56 times higher for Pfizer and 1.75 times higher for Moderna than the conventional booster vaccine. It is expected to be more effective than the conventional type. If the production of neutralizing antibodies increases, it is thought that the infection prevention effect will also increase. It is also expected to be more effective in preventing severe disease than conventional vaccines. Both vaccines are considered to be effective to some extent against BA.5, which is currently prevalent in Japan.

Regarding side effects after vaccination, both companies reported mild to moderate symptoms such as pain at the injection site, dullness, headache, muscle pain, joint pain, chills, and fever, which were generally the same as for conventional vaccines. increase.

This vaccine is approved as a booster dose, so it is for people who have completed two doses. It is positioned as a temporary inoculation based on the Immunization Act and can be inoculated free of charge. For those who have been inoculated for 5 months or more since the last vaccination, Pfizer is 12 years old or older, and Moderna is 18 years old or older.

Elderly people aged 60 and over, people aged 18 and over with underlying diseases, and healthcare workers who are targeted for the 4th dose of the conventional vaccine will be given priority to be vaccinated after September 20th. After mid-October, all people aged 12 and over who have completed two doses of the vaccine and five months have passed since the last dose can be vaccinated.

Currently, BA.5 among Omicron strains is the main cause of infection, but Pfizer has already applied for approval of vaccines for BA.4 and BA.5, and is expected to be introduced soon. . This vaccine is said to have increased neutralizing antibodies against BA.4 and BA.5 and has certain efficacy.