Waning of vaccine effectiveness against moderate and severe covid-19 among adults in the US from the VISION network: test negative, case-control study

Abstract

Objective To estimate the effectiveness of mRNA vaccines against moderate and severe covid-19 in adults by time since second, third, or fourth doses, and by age and immunocompromised status. Design Test negative case-control study. Setting Hospitals, emergency departments, and urgent care clinics in 10 US states, 17 January 2021 to 12 July 2022. Participants 893 461 adults (≥18 years) admitted to one of 261 hospitals or to one of 272 emergency department or 119 urgent care centers for covid-like illness tested for SARS-CoV-2. Main outcome measures The main outcome was waning of vaccine effectiveness with BNT162b2 (Pfizer-BioNTech) or mRNA-1273 (Moderna) vaccine during the omicron and delta periods, and the period before delta was dominant using logistic regression conditioned on calendar week and geographic area while adjusting for age, race, ethnicity, local virus circulation, immunocompromised status, and likelihood of being vaccinated. Results 45 903 people admitted to hospital with covid-19 (cases) were compared with 213 103 people with covid-like illness who tested negative for SARS-CoV-2 (controls), and 103 287 people admitted to emergency department or urgent care with covid-19 (cases) were compared with 531 168 people with covid-like illness who tested negative for SARS-CoV-2. In the omicron period, vaccine effectiveness against covid-19 requiring admission to hospital was 89% (95% confidence interval 88% to 90%) within two months after dose 3 but waned to 66% (63% to 68%) by four to five months. Vaccine effectiveness of three doses against emergency department or urgent care visits was 83% (82% to 84%) initially but waned to 46% (44% to 49%) by four to five months. Waning was evident in all subgroups, including young adults and individuals who were not immunocompromised; although waning was morein people who were immunocompromised. Vaccine effectiveness increased among most groups after a fourth dose in whom this booster was recommended. Conclusions Effectiveness of mRNA vaccines against moderate and severe covid-19 waned with time after vaccination. The findings support recommendations for a booster dose after a primary series and consideration of additional booster doses.

Predictors of Willingness of the General Public to Receive a Second COVID-19 Booster Dose or a New COVID-19 Vaccine: A Cross-Sectional Study in Greece

“…Thus, reliable information regarding the need for and importance of boosters should be provided to previously vaccinated individuals by adhering to post-marketing surveillance and optimizing the compensation policy after side effects [32,33]. For instance, the belief that primer COVID-19 vaccine doses are sufficient and provide immunization is wrong since literature suggests that antibody levels and vaccines effectiveness decrease over time even after a first booster [3,4,34].…”

“…On the other hand, the existing booster vaccination program produces broad but incomplete immunity against SARS-CoV-2 variants, including Omicron [3]. Moreover, real-world evidence has shown waning first booster dose effectiveness over time against new COVID-19 infections and hospitalization, especially for the Omicron variant [4].…”

Global COVID-19 Pandemic Outcomes: Dissecting a Failed Strategy

“…Therefore, booster doses became necessary. [25][26][27][28][29][30][31][32][33] Despite an aggressive booster campaign, the same results occurred when the Omicron variant emerged in Fall of 2021. By January 2022 case rates, both globally and in the US, reached the highest levels of the pandemic, far surpassing those at the beginning of 2021 when the vaccines were being rolled out.…”

Nationwide analysis of COVID-19 death rate throughout the pandemic in Italy

“…Confronting the data garnered from our analysis with the recent death rate of influenza in that same country (i.e., 0.32%), it is then evident that SARS-CoV-2 was over tenfold more lethal than the Influenza virus at the beginning of the pandemic, but COVID-19 has now paradoxically become 36% less fatal than flu at the beginning of November 2022 (Figure 1). Importantly, several lines of evidence attest that the efficacy of COVID-19 vaccination against symptomatic and severe COVID-19 illness slowly but progressively wanes over time (30), while the potential risk that more virulent and aggressive SARS-CoV-2 variants will emerge in the future cannot be discounted (31).…”