Covid-19 vaccine protects people of all body weights: Lancet study

PTI

London, July 1

Covid-19 vaccines significantly reduced the number of cases of severe covid for everyone regardless of their body size, according to a study of 90 lakh adults in England published in The Lancet Diabetes and Endocrinology on Friday.

Vaccine effectiveness was similar for those with a higher body mass index (BMI) and of a healthy weight, but slightly lower in the underweight group, who were also the least likely to have been vaccinated, the researchers said.

In a further analysis of vaccinated people only, among the fewer covid cases recorded, people of very low and very high BMI were more likely to experience severe disease than vaccinated healthy weight people, they said.

“Our findings provide further evidence that covid vaccines save lives for people of all sizes,” said study lead author Carmen Piernas from the University of Oxford, UK.

They searched anonymised health records from more than 12 million patients in England taking part in QResearch – a secure database of healthcare information available to verified researchers.         

People were grouped based on their BMI according to four World Health Organisation definitions of 18.5-24.9 kg per square metre (kg/m2) for healthy weight, below 18.5 for underweight and 25- 29.9 for overweight.

Characteristics such as age, sex, smoking status, and social deprivation were also accounted for in the analysis. Of over 90 lakh people included in the study, 566,461 (over 5.6 lakh) tested positive for SARS-CoV-2 during the study from December 8, 2020 (date of the first vaccine given in the UK) to November 17, 2021.

Of those, 32,808 were admitted to the hospital and 14,389 died.

To understand vaccine effectiveness, the researchers compared risk of severe disease in vaccinated versus non-vaccinated people at least 14 days after a second dose.

They found that being vaccinated offered high protection across all BMI groups, but that the effect was slightly lower in underweight people.

Underweight vaccinated people had around half the likelihood of being hospitalised or dying compared with unvaccinated people of the same BMI.