COVID-19 vaccination protected individuals of all physique sizes from hospitalization and loss of life—though vaccinated individuals with a low or excessive physique mass index (BMI) have been at larger danger, in response to a research of adults in England revealed yesterday in The Lancet Diabetes & Endocrinology.
College of Oxford researchers led the research, which concerned 9,171,524 grownup major care sufferers in England with out there physique mass index (BMI) knowledge from Dec 8, 2020 (when the COVID-19 vaccine first grew to become out there in the UK), to Nov 17, 2021. Common affected person age was 52 years, and common BMI was 26.7 kilograms per meter squared (kg/m2) (obese).
Elevated danger at low, excessive BMIs
Of the 9,171,524 sufferers, 566,461 examined constructive for COVID-19 throughout follow-up, 32,808 have been hospitalized, and 14,389 died. Amongst all sufferers, 19.2% have been unvaccinated, 3.1% had acquired one vaccine dose, 52.6% had acquired two doses, and 25.0% had had three doses at the least 14 days earlier than enrollment.
By the top of the research interval, 23.3% of healthy-weight members, 32.6% of the underweight group, 16.8% of obese members, and 14.2% of the overweight group remained unvaccinated. Over 80% of individuals aged 40 and older who have been obese or overweight had acquired two or three COVID-19 vaccine doses, in contrast with 70% to 83% of their underweight friends.
Whereas vaccine safety various considerably throughout BMI classes, general safety in opposition to extreme an infection was excessive in opposition to hospitalization, with an odds ratio [OR] for underweight of 0.51 (95% confidence interval [CI], 0.41 to 0.63), an OR for wholesome weight of 0.34 (95% CI, 0.32 to 0.36], an OR for obese of 0.32 (95 CI, 0.30 to 0.34), and an OR for weight problems of 0.32 (95% CI, 0.30 to 0.34).
Equally, ORs for loss of life have been 0.60 for underweight (95% CI, 0.36 to 0.98), 0.39 for wholesome weight (95% CI, 0.33 to 0.47), 0.30 for obese (95% CI, 0.25 to 0.35), and 0.26 for weight problems (95% CI, 0.22 to 0.30).
Whereas vaccinated underweight members have been at about half the danger of hospitalization or loss of life than unvaccinated individuals with the identical BMI, these with wholesome or excessive BMIs have been about 70% much less more likely to be hospitalized than their unvaccinated friends. Contributors with wholesome or excessive BMIs have been roughly two-thirds much less more likely to die after a second vaccine dose.
Among the many vaccinated group, the danger of extreme illness at high and low BMIs was considerably greater than at wholesome BMIs. For example, a BMI of 17 was tied to a 50% greater danger of hospitalization than a wholesome BMI of 23, whereas a really excessive BMI of 44 was related to thrice the danger of hospitalization than a wholesome BMI.
Function of impaired immune responses
The researchers mentioned that the outcomes might be attributed to an altered immune response in individuals with greater BMIs and that thinner members might have impaired immunity due to frailty, most cancers, or different circumstances linked to low physique weight. “These outcomes recommend the necessity for focused efforts to extend uptake in individuals with low BMI (<18.5 kg/m2), in whom uptake is decrease and vaccine effectiveness appears to be diminished,” they wrote.
In a Lancet information launch, lead writer Carmen Piernas, PhD, mentioned that the outcomes are encouraging for individuals with weight problems, who’re at elevated danger of poor COVID-19 outcomes. “Our outcomes present reassurance to individuals with weight problems that COVID-19 vaccines are equally as efficient for them as for individuals with a decrease BMI, and that vaccination considerably reduces their danger of extreme sickness if they’re contaminated with COVID-19,” she mentioned.
In a associated commentary, Annelies Wilder-Smith, MD, PhD, and Annika Frahsa, PhD, each of the College of Berne in Switzerland, mentioned that weight problems and COVID-19 are a dangerous mixture, as are weight problems and different infectious illnesses such because the flu.
“Moreover, individuals with weight problems within the UK have additionally been affected by the pandemic lockdown measures with elevated overeating, diminished bodily exercise behaviour, and elevated limitations to weight administration,” they wrote. “Tackling weight problems as a societal downside now will assist mitigate the disastrous penalties of the present COVID-19 pandemic and people of future pandemics.”