The ability to infect Covid in the air could decrease by 90% within 20 minutes of exhalation
See all the news about the coronavirus
Vaccines against Covid-19 have greatly reduced the number of severe cases of this disease in all people, regardless of their body size, according to the largest study to date on the relationship between vaccine effectiveness and the rate of infection. body mass (BMI).
The study, conducted on some nine million adults in England and published this Friday in the journal ‘The Lancet Diabetes & Endocrinology’points out that the effectiveness of the vaccine was similar in people with a higher BMI and in those with a healthy weight, but slightly lower in the underweight group, which is also less likely to be vaccinated, reports Servimedia.
Obesity was identified as a risk factor for Covid-19 serious at the beginning of pandemic. However, little was known until now about the effectiveness of the vaccine in people with obesity. Previous work has shown that this sector of the population is less likely to be vaccinated against seasonal flu and has modestly reduced benefits from flu shots.
“Our findings provide further evidence that COVID-19 vaccines save lives for people of all sizes. Our results reassure people with obesity that COVID-19 vaccines are just as effective for them as they are for people.” with a BMI lower, and that vaccination substantially reduces the risk of serious illness if they are infected with covid-19,” says Carmen Piernas, from the Nuffield Department of Primary Care Health Sciences, at the University of Oxford (United Kingdom).
The researchers searched anonymous health records for more than 12 million patients in 1,738 GP practices in England that participate in QResearch, a secure database of healthcare information available to verified researchers. Of these, 9,171,524 patients over 18 years of age, with BMI data and who had not previously been infected by the SARS-CoV-2 virus were included in the study.
People were grouped according to their BMI in one of the four definitions of the World Health Organization (WHO): healthy weight (18.5 to 24.9 kg/m2), underweight (less than 18.5), overweight (25 to 29.9), and obesity (30 or more). There were adjusted levels in Asian people to reflect the higher health risks at lower BMI levels in this group. Characteristics such as age, gender, smoking, and social deprivation were also taken into account in the analyses.
Of more than nine million people included in the study, 566,461 tested positive for SARS-CoV-2 during the study from December 8, 2020 (date of the first vaccine administered in the UK) to November 17, 2021. Of these, 32,808 were hospitalized and 14,389 died.
At the end of the study period, 23.3% of the healthy weight group (817,741 of 3,509,231 people), 32.6% of the low weight group (104,488 of 320,737 people), 16.8% of the of overweight (513,570 of 3,062,925 people) and 14.2% of the obese group (322,890 of 2,278,649 people) had not received any dose of any vaccine against covid-19.
To understand the effectiveness of the vaccine, the researchers compared the risk of severe disease in vaccinated and unvaccinated people at least 14 days after a second dose. They found that being vaccinated offered high protection in all BMI groups, but that the effect was slightly less in the underweight. Underweight vaccinated people were about half as likely to be hospitalized or die compared to unvaccinated people of the same weight.
By comparison, people in the healthy and high BMI groups who were vaccinated were about 70% less likely to be hospitalized than unvaccinated people. Having a healthy BMI or higher is about two-thirds less likely to die than unvaccinated people of that weight two weeks after a second dose.
Looking at data from vaccinated people only (among whom the number of Covid-19 cases dropped sharply), the researchers found that after two doses of the vaccine there was a significantly increased risk of severe illness with low BMI and high compared to a healthy BMI.
#vaccine #protects #people #weight #severe #Covid19