The coronavirus disease 2019 (COVID-19) pandemic has caused more than 438 million documented cases, with more than 5.96 million deaths worldwide. The high number of deaths within a year of the outbreak spurred the development of vaccines for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the Pfizer-BioNTech messenger ribonucleic acid (mRNA) vaccine ) being the first to receive an Emergency Use Authorization (EUA) in the United States.
As billions of doses have been deployed in this country, a new study shows the impact of the vaccination program on the state of public health in the United States. This is important in shaping future decisions about vaccination as a public health strategy and at the personal level.
Randomized clinical trials (RCTs) and real-world data show that COVID-19 vaccines have high efficacy against SARS-CoV-2 infection and disease severity. The largest effect was on the number of symptomatic infections, deaths and hospitalizations.
This study, published on medRxiv* preprint server, discusses the cost-effectiveness of the vaccine strategy using the Pfizer vaccine as the index intervention. Previous research has explored this aspect in relation to the healthcare system. Additionally, this study examines the effects of vaccination with the Pfizer vaccine on productivity and its economic impact, using data from several high-quality studies for quantitative analysis.
The researchers aimed to determine the impact of this vaccine on public health at one year, using a combination of statistical methods. The target group included the US population aged 12 and older, with information on clinical characteristics, type, number and location of contacts, virus spread, human economic and behavioral factors being used to analyze the impact of the vaccine on this group. .
Vaccine coverage was derived from official data, while various studies were exploited to obtain data on vaccine efficacy after one or two doses of this vaccine, as well as the duration of protective immunity induced by the vaccine .
The various outcomes studied included the number of deaths and symptomatic cases averted, both in outpatient and inpatient settings. The economic results were estimated by the quantitative reduction in the use of health care and the reduction in costs for society.
What did the study show?
Researchers estimated 12% had prior infection with the virus among the vaccine-eligible U.S. population, or about 33 million. Without vaccination, about a quarter of the susceptible eligible population would have been infected, they estimated, by 2021.
About 60% would be due to the Delta strain, while more than a fifth would be due to the ancestral strain. More than one in seven was caused by Alpha and 2% by Gamma. Overall, they estimated that 3.5 million hospitalizations would have occurred without vaccination and nearly half a million deaths.
The official Centers for Disease Control and Prevention (CDC) tracker shows very similar estimates. Thus, the primary series of the Pfizer vaccine averted approximately 8.7 million symptomatic cases, 690,000 hospitalizations and 110,000 deaths from COVID-19.
More than 77% of deaths and almost 55% of hospitalizations were in people aged 65 or over, who suffered less than a fifth of deaths. Almost 73% of hospital stays were not associated with the use of a mechanical ventilator, while a quarter were in the intensive care unit (ICU). Of these, more than half required mechanical ventilation, compared to 5% of those in normal service.
The vaccine is estimated to have increased years of life and quality-adjusted life years (QALYs) by more than one million, primarily by averting COVID-19-related deaths. A smaller effect was due to a reduction in symptoms of infection and chronic adverse effects of mechanical ventilation.
Productivity has been gained, to the tune of $44 billion, of which more than one-third is due to less productivity loss due to premature deaths and two-thirds to reduced work absences due to symptomatic COVID-19.
What are the implications?
According to these findings, the Pfizer vaccine is linked to a significant public health impact in the United States. The mechanisms include preventing millions of symptomatic cases of COVID-19, thousands of hospitalizations and thousands of deaths. Directly correlated to these effects, billions of dollars would have been saved directly by avoiding health care payments and indirectly by avoiding lost productivity.
This is consistent with other studies that have shown that vaccination reduces the societal burden of COVID-19. This shows that even without taking into account the indirect benefits of vaccination, such as reduced viral transmission and the opening of businesses and public places, immunity approaches population immunity levels.
This is the first study to assess multiple outcomes after vaccination using multiple types of data, including clinical severity, epidemiological characteristics, economic parameters and others, to arrive at an estimate of the impact of this vaccine on public health in the American population. However, it did not include children or certain high-risk groups who did not respond as expected to the vaccine.
The results of this study may not fully reflect current or future disease trends (e.g., Omicron variant prevalence), clinical profile of the vaccine, use of healthcare resources, and costs. . As data on COVID-19 continues to expand and rapidly evolve, future studies are warranted to assess the public health impact in these additional settings as well as longer term..”
medRxiv publishes preliminary scientific reports that are not peer-reviewed and, therefore, should not be considered conclusive, guide clinical practice/health-related behaviors, or treated as established information.