Affiliation:
1. NOVA Medical School NOVA University of Lisbon Lisbon Portugal
2. Departments of Medicine, of Epidemiology and Population Health, of Biomedical Data Science, and of Statistics, and Meta‐Research Innovation Center at Stanford (METRICS) Stanford University Stanford California USA
3. Department of Epidemiology and Biostatistics University of California San Francisco San Francisco California USA
Abstract
AbstractAnnual vaccination is widely recommended for influenza and SARS‐CoV‐2. In this essay, we analyse and question the prevailing policymaking approach to these respiratory virus vaccines, especially in the United States. Every year, licensed influenza vaccines are reformulated to include specific strains expected to dominate in the season ahead. Updated vaccines are rapidly manufactured and approved without further regulatory requirement of clinical data. Novel vaccines (i.e. new products) typically undergo clinical trials, though generally powered for clinically unimportant outcomes (e.g. lab‐confirmed infections, regardless of symptomatology or antibody levels). Eventually, the current and future efficacy of influenza and COVID‐19 vaccines against hospitalization or death carries considerable uncertainty. The emergence of highly transmissible SARS‐CoV‐2 variants and waning vaccine‐induced immunity led to plummeting vaccine effectiveness, at least against symptomatic infection, and booster doses have since been widely recommended. No further randomized trials were performed for clinically important outcomes for licensed updated boosters. In both cases, annual vaccine effectiveness estimates are generated by observational research, but observational studies are particularly susceptible to confounding and bias. Well‐conducted experimental studies, particularly randomized trials, are necessary to address persistent uncertainties about influenza and COVID‐19 vaccines. We propose a new research framework which would render results relevant to the current or future respiratory viral seasons. We demonstrate that experimental studies are feasible by adopting a more pragmatic approach and provide strategies on how to do so. When it comes to implementing policies that seriously impact people's lives, require substantial public resources and/or rely on widespread public acceptance, high evidence standards are desirable.
Funder
University of California, San Francisco
Reference131 articles.
1. Impact of infectious diseases on population health using incidence-based disability-adjusted life years (DALYs): results from the Burden of Communicable Diseases in Europe study, European Union and European Economic Area countries, 2009 to 2013
2. Centers for Disease Control and Prevention.Frequently asked questions about estimated flu burden.2021. Accessed December 15 2023.https://www.cdc.gov/flu/about/burden/faq.htm
3. World Health Organization.Global Influenza programme. Accessed December 15 2023.https://www.who.int/teams/global‐influenza‐programme/surveillance‐and‐monitoring/burden‐of‐disease
4. Centers for Disease Control and Prevention.RSV Surveillance & Research Published.2023Accessed December 15 2023.https://www.cdc.gov/rsv/research/index.html
5. World Health Organization.14.9 million excess deaths associated with the COVID‐19 pandemic in 2020 and 2021. Accessed December 15 2023.https://www.who.int/news/item/05‐05‐2022‐14.9‐million‐excess‐deaths‐were‐associated‐with‐the‐covid‐19‐pandemic‐in‐2020‐and‐2021#:~:text=New%20estimates%20from%20the%20World 13.3%20million%20to%2016.6%20million