COVID Vaccination reduces Infection severity and Hospitalization: Lancet

In this study, researchers at Hull Teaching Hospitals in England evaluated the effect of the Pfizer-BioNtech vaccine (BNT 162b2) in both symptomatic and asymptomatic COVID-19 infections. The study findings were published in the Clinical Infectious Diseases on April 24, 2021.

Upon evaluation, the researchers found that the infection rate reduced in both symptomatic and asymptomatic COVID patients as the vaccination withBNT162b2 increased from 8.3% to 82.5%. They also reported that the vaccination was associated with a significant reduction in symptomatic and asymptomatic SARS-CoV-2 cases.

The authors concluded, “single dose BNT162b2 (Pfizer vaccine) has been associated with a significant decrease in positive PCR for SARS-CoV-2 in both symptomatic and asymptomatic HCW’s (healthcare workers) with the most dramatic effect on symptomatic illness. Utility of LFD (lateral-flow device) testing positive test rate seems to be unaffected by the vaccine roll out and may continue to provide a useful screening tool in vaccinated cohorts.”

STUDY 3:

In this Scottish-population based study, University of Edinburgh researchers evaluated the association between the mass roll-out of the first doses of Pfizer and AstraZeneca vaccines and hospital admissions for COVID-19. The research has been published in THE LANCET on April 23, 2021.

The researchers used the Early Pandemic Evaluation and Enhanced Surveillance of COVID-19 (EAVE II) database to compile the vaccination, primary care, coronavirus testing, and hospitalization records of 5.4 million people in Scotland registered at 940 general practice clinics, representing about 99% of the population.

Upon analysis, they found that the first dose of Pfizer vaccine was associated with a vaccine effect of 91% for reduced COVID-19 hospital admission at 28–34 days post-vaccination, compared with 88% with the AstraZeneca vaccine.

They also found that the effectiveness of both vaccines was similar (83%) when the analysis was restricted to those 80 years and older.

The authors concluded, “Mass roll-out of the first doses of the BNT162b2 mRNA and ChAdOx1 vaccines was associated with substantial reductions in the risk of hospital admission due to COVID-19 in Scotland. There remains the possibility that some of the observed effects might have been due to residual confounding.”

The findings of these studies suggest that vaccination either one or two-dose effectively prevents both symptomatic and asymptomatic infections and related hospitalizations and further encouraged the use of personal protective equipment.

REFERENCES:

1. Study 1: Victoria Jane Hall,Sarah Foulkes et al. COVID-19 vaccine coverage in health-care workers in England and effectiveness of BNT162b2 mRNA vaccine against infection (SIREN): a prospective, multicentre, cohort study. The Lancet (2021), ISSN: 0140-6736 doi:https://doi.org/10.1016/S0140-6736(21)00790-X.

2. Study 2: Patrick J Lillie, Paul O’Brien et al. First dose of BNT162b2 mRNA vaccine in a Health Care Worker cohort is associated with reduced symptomatic and asymptomatic SARS-CoV-2 infection. Clinical Infectious Diseases, ciab351, doi: https://doi.org/10.1093/cid/ciab351.

3. Study 3: Eleftheria Vasileiou, PhD, Prof Colin R Simpson, PhD et al. Interim findings from first-dose mass COVID-19 vaccination roll-out and COVID-19 hospital admissions in Scotland: a national prospective cohort study. The Lancet (2021), ISSN: 0140-6736. doi:https://doi.org/10.1016/S0140-6736(21)00677-2.