Booster Shot, Effectiveness of COVID-19 Vaccine

Clinical the study The mRNA vaccine developed by Pfizer-BioNTech and Moderna has initially been shown to be more than 90% effective against serious COVID-19 disease.

The Johnson & Johnson vaccine has been found to be slightly less effective, but it is still more protective against hospitalization.

However, researchers at the University of California, San Diego I have written Last week’s New England Journal of Medicine attributed the efficacy of the mRNA vaccine to symptomatic COVID-19 cases to 65% by July 2021, due to the decline in efficacy over time. Stated.

“The decline in effectiveness is not surprising at all,” he said. Dr. Francesca Triani, Professor of Clinical Medicine in the Department of Infectious Diseases and Global Public Health, University of California, San Diego School of Medicine, and Program Director of Infection Prevention and Clinical Epidemiology, University of California, San Diego.

“Clinical trial data suggest that reduced efficacy occurs months after complete vaccination, but our findings show that vaccine efficacy against mild symptomatic disease is significant in the face of delta variants. It is low, indicating that it has declined 6 to 8 months after vaccination is complete, “Torriani explained.

Jonathan H. Watanabe, Ph.D., PhD, COVID-19 Health Outcome Researcher and Vice Dean of Assessment and Quality at the University of California, Irvine, found that the efficacy of mRNA vaccines appears to decrease by about 6% every two months. The study has shown to Healthline.

on the other hand, study In conclusion from Israel, the third booster dose of the mRNA vaccine seemed to significantly restore the protective effect.

“We found that the probability of being positive for SARS-CoV-2 infection 7-13 days after booster shots was reduced by 48-68% and the marginal effect increased to 70-70 days 14-20 days after booster shots. 84 Percentage, “reported Maccabi Healthcare Services researchers.

“There isn’t much discussion about administering antibody boosts to the most prevalent ones. [Delta] Variant, “says Watanabe.

Mid-August, US Department of Health and Human Services (HHS) Presentation We plan to provide COVID-19 booster shots to people who have previously been given both doses of Pfizer or Moderna vaccine.

Authorities cite concerns that vaccine efficacy is “especially at high risk or may decline in the coming months among people vaccinated in the early stages of vaccination deployment.” bottom.

“Available data show very clearly that protection against SARS-CoV-2 infection begins to diminish over time after the first dose of vaccination, with respect to mildness in relation to the predominance of delta variants. Evidence of reduced defense is beginning to be seen, and moderate illness, “according to a policy statement issued by HHS.

HHS officials said booster shots will be available from the week of September 20th.

According to the HHS, those who were initially vaccinated with the mRNA vaccine eight months ago, “including many healthcare providers, nursing home residents, and other elderly people,” and residents of long-term care facilities are prioritized.

Unlike the first mRNA deployment in early 2021, age does not directly prioritize booster shots.

However, the first American to be vaccinated as soon as it becomes available to people over the age of 65 is one of the first to be eligible for a booster shot.

Studies on vaccine decline have not been definitive as to whether protection weakens more rapidly among people over the age of 65.

Israeli studies suggest that older people are less effective than other age groups. However, New York study Those published by the Centers for Disease Control and Prevention (CDC) did not find such disparities.

According to HHS, booster shots for Johnson & Johnson vaccinated people are also “likely to be needed”, but the time frame is different because the vaccine was not started until March 2021. increase.

As long as the majority of the population remains unvaccinated and new variants continue to be developed through the expansion of the disease-uncontrolled community, more booster shots may be needed, Watanabe said.

“The reality of this vaccine is to continue this until we actually reach over 70% of herd immunity,” he said.

Watanabe warned against concluding that the COVID-19 vaccine would not work just because booster shots were recommended.

Influenza vaccination is required annually, and booster vaccinations are common with many other commonly administered vaccines such as tetanus, hepatitis, and measles, he said.

“Although efficacy may have diminished, the vaccine still provides a very effective defense against severe COVID-19 disease,” he said.