Effectiveness of Covid Bivalent Vaccine
Previous blogs reviewed and summarized COVID vaccination trends via UK and New South Wales (NSW) COVID Surveillance Reports. Published almost a year apart, the trends of each are in agreement. The findings demonstrated an increase in hospital admissions, ICU admissions, and deaths with increasing numbers of vaccination doses.
These blogs can be accessed here:
A preprint study was published in September 2022 by Cleveland Clinic assessing the effectiveness of the bivalent booster vaccine against Covid-19. The findings were unexpected and support trends seen in the UK and NSW blogs. This blog will summarize the study: “Effectiveness of the Coronavirus Disease 2019 (COVID-19) Bivalent Vaccine.”
Background of Bivalent Booster Shot
With the emergence of the Omicron variant in December of 2021, individuals previously vaccinated were no longer protected and immunity from the vaccine waned within a few months. This spurred the production of newer vaccines to offer further protection.
The bivalent mRNA vaccines were approved by the FDA on August 31, 2022, based on:
- A Pfizer animal study of 8 mice,
- Clinical data from original vaccines,
- Nonclinical data of a bivalent vaccine not identical to the current variant,
- A clinical study of a bivalent vaccine “similar to each of the vaccines being authorized” but also not identical.
Further detail on the bivalent boosters can be reviewed here: “Bivalent Boosters For COVID. What Should You Do?”
Study Purpose and Methods
The purpose of the study was to evaluate whether the new bivalent vaccine protects against COVID. Multiple variants circulated during the time period of the study. This is a retrospective cohort study at the Cleveland Clinic in which data was cumulatively collected on employees who received the bivalent vaccine when it first became available on September 12, 2022. It included 51,011 subjects over the course of 13 weeks. Protection provided by the vaccine was evaluated over time.
Results: The Higher Number of Vaccines Received, the Higher the Risk of Contracting COVID
The bivalent booster showed an overall effectiveness of 30%.
Of all participants, 87% received 1 vaccine, 83% received 2 vaccines, 53% received 3 vaccines, and 8% received 4 vaccines.
An unexpected finding was concluded from this study:
Not only are those with more vaccine doses more likely to get COVID, but also those who have received the bivalent booster are more likely to get COVID.
The results show the higher number of vaccines received, the higher the risk of contracting COVID, as seen in the UK and NSW data. The following figure from the study shows this trend (number of doses denoted on the right):
Conclusion
The authors conclude: “We still have a lot to learn about protection from COVID-19 vaccination, and in addition to a vaccine’s effectiveness it is important to examine whether multiple vaccine doses given over time may not be having the beneficial effect that is generally assumed.”
Stated in the study, “There were too few severe illnesses for the study to be able to determine if the vaccine decreased severity of illness.”
Present day, COVID infection is mild for most, the vaccine has low effectiveness, increasing vaccine doses are resulting in increased risk of infection, and there is minimal safety data on the vaccines.
With this known and at this point in time – is it ethical to continue to suggest booster shots and make assumptions about their safety and benefit especially in children?
Have an awesome day! Dr D