Preprint article
"Main
... COVID-19 vaccine effectiveness in the real world for the 2023–2024 monovalent XBB.1.5 vaccine stands at ~ 50% (95% CI = 44–55%). Protection against intensive care unit admission and death had an effectiveness at ~ 40% (95% CI = 16–58%) 4–6 months after the dose. Its effectiveness in immunocompromised individuals ≥ 18 years against COVID-19–associated hospitalization was 38% in the 2 months following receipt of an updated vaccine. Triple and quadruple mRNA vaccinated individuals were unable [to] mount any significant antibody responses to newly emerging SARS-CoV-2 variants in the summer of 2024, with vaccinated individuals exhibiting antibody evasion properties...
In a global study entitled people’s response to vaccine effectiveness and safety (PROVES), we surveyed both vaccinated and unvaccinated people about their pre-existing health conditions, mental health, COVID symptoms, and vaccine-associated adverse events (AEs)...
Results
... Vaccine AE-associated hospitalization was reported by 6.24% (56/898) individuals compared with 1.06% (25/2351) of unvaccinated individuals with COVID-19...
Discussion
... When PASCs [postacute sequelae] were compared between unvaccinated and vaccinated individuals after first SARS-CoV-2 infection, vaccinated individuals did not have any clear advantage... Risk reduction against moderate/severe COVID-19 in mRNA vaccinated individuals was 15.45% in <6 months vaccinated and 21.7% in >6 months vaccinated, whereas there was no benefit of mRNA or adenovirus COVID-19 vaccines on severe disease...
In our cohort, 56.30% and 45.95% of the individuals reported COVID-19 vaccine-associated AEs within 7days of receiving the 1st or the 2nd dose, respectively. In a side-by-side comparison of vaccine AEs reported by SARS-CoV-2 naïve individuals as compared to PASC reported after 1st SARS-CoV-2 infection in unvaccinated individuals, 6.24% vaccinated (56/898) vs 1.06% unvaccinated (25/2351) individuals reported hospitalization... In 2023–2024, ≥90% COVID-19 vaccine recipients (Pfizer, Moderna, or Novavax) reported non-serious adverse events, whereas ≥10% of the recipients reported serious adverse events within 7 days after vaccination to V-safe. Serious AEs resulted in individuals being unable to complete daily activities and included a report of one of the following: death, life-threatening illness, hospitalization or prolongation of hospitalization, and permanent disability...
The human challenge study also revealed.. SARS-CoV-2 virus could still be detected by RT-PCR in 85% of the individuals at the time of discharge (nearly 19 days after exposure) and in another 33% of the individuals 28 days post-exposure. Viable virus could only be retrieved ~6.5 days (median) from nasopharyngeal swabs and the study found no correlation between viability and RT-PCR load"
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