A study by the Centers for Disease Control and Prevention (CDC) showed that the COVID-19 vaccine booster shot (boost shot) was effective in preventing hospitalization even during the outbreak of Omicron mutation.
The CDC again recommended that people over 50 immediately receive the second booster shot (fourth dose in the case of Pfizer and Moderna vaccines). point was also suggested.
According to the data on the effectiveness of the COVID-19 vaccine released by the CDC on the 15th of July.
However, from around April, when BA.2 and BA.2.12.1, which are sub mutations of BA.1, became dominant species, the hospitalization prevention effect of the basic vaccination dropped to 24%.
This is a result of reflecting the sub-mutation characteristics that have strengthened the immunity of existing vaccines.
However, the booster shot exerted a strong force even during the period when these sub-mutations were prevalent.
At the time of less than 3 months after the first booster shot (3rd inoculation), the hospitalization prevention effect reached 69%, and even after that, it showed a level of 52%.
At the end of March, the United States recommended the second booster shot (4th dose) for those over 50 and some immunocompromised people, but the effect of the 4th dose was better.
For one week after the fourth inoculation, the prevention of hospitalization reached 80%. This is much higher than the 55% prevention effect of hospitalization at 4 months after the third vaccination in the age group over 50 years old.
In announcing these results, the CDC emphasized that “those who are eligible for the booster shot should be vaccinated immediately.”
“Considering the recent increase in the number of deaths and hospitalizations infected with BA.5, it is important to keep up-to-date with the recommended vaccine for everyone, including boosters over 50 years of age and immunocompromised people.”.
The New York Times reported on the same day that federal health officials emphasized the importance of booster shots, suggesting that they may receive a booster dose of an improved vaccine developed to protect against sub mutations this fall or winter.
To minimize the damage caused by COVID-19, the US health authorities have requested vaccine manufacturers Pfizer and Moderna to develop vaccines that block BA.
In the worst-case scenario in the United States, it is estimated that 200,000 COVID-19 deaths could occur in the United States alone within the next year.
For that reason, the US is also considering a plan to expand the fourth dose to all adults in consideration of the effect of the booster shot.
In this study, the CDC did not measure the effect of booster shots on BA.5, which is now the dominant species worldwide.
It is known that BA.5 is the mutation that best evades immunity among the sub-mutations of Omicron. As a result, the number of confirmed cases and hospitalized patients around the world is increasing rapidly.
The United States has extended the public health emergency by three months to the 13th to actively respond to the highly contagious mutation.