According to an October 1st posting on ProMED mail a study was conducted in the U.K. on hospitalizations and fatality in recipients of a single dose of either Pfizer or AstraZeneca vaccine. The purpose was to identify and quantify the effect of predisposing factors to select among alternative treatment plans.
Of 2.6 million people vaccinated, 883 (0.03 percent) required hospitalization with 541 fatalities (0.02 percent). The high fatality rate among those hospitalized (61.3 percent) confirms the pathogenicity of SARS-Co-V virus in patients with comorbidities, even if vaccinated.
Risks factors included age exceeding 80 years, having five or more comorbidities, having been hospitalized during the previous four weeks, resident in a care home, current or ex-smoker and socioeconomic deprivation.
The results of the study indicate priorities for potential recipients of a third booster dose of a mRNA vaccine or for those receiving a single dose adenovirus vector vaccine. In the U.S., a booster dose is currently available for those having received the two-dose Pfizer sequence six months previously if over 65 years in age, engaged in a high-risk occupation or suffering from one or more predisposing conditions.