B.1.1.7 is more transmissible, but does not increase the severity of the disease, two new studies indicate

One of the studies, published Monday in The Lancet Infectious Diseases, found no evidence in a sample of patients admitted to the hospital that the B.1.1.7 variant was associated with severe Covid-19. However, the variant is associated with increased viral load, which supports the growing evidence that it is more easily transmitted.

The other study, which was also published in The Lancet Public Health on Monday, found no statistically significant association between the B.1.1.7 variant and the types or duration of Covid-19 symptoms that people reported.

The Lancet Infectious Diseases study contains data on 496 people admitted to London hospitals who tested positive for coronavirus infection.

“Our data, within the context and limitations of an actual study, provide initial assurance that the severity of patients with B.1.1.7 hospitalized does not differ significantly from the severity of those without, and this study offers a model to answer the same question again as we move into an era of emerging variants, ‘the researchers in the UK wrote in the study.

Nasal and throat swab samples were collected from the patients between November 9 and December 20. Among the samples, 341 underwent genome sequencing. The sequence data showed that 198 of the patients, or 58%, had infections caused by the B.1.1.7 variant, while the others were caused by other strains of the coronavirus.

The researchers found no difference in the outcome of serious illnesses or deaths between the variant and other sexes.

For example, the data showed that 36% of the patients in the study with the B.1.1.7 infection experienced serious illnesses or deaths compared to 38% of those with non-B.1.1.7 infections. When it specifically came to death, 16% of the B.1.1.7 infection died within 28 days compared to 17% of those who did not have B.1.1.7 infections, the researchers found.

However, the researchers identified an increased virus load among the B.1.1.7 patients.

In general, “patients with B.1.1.7 were younger and had fewer disease states than those with non-B.1.1.7 infection, possibly indicating the widespread and potentially increased transmission of this variant in the community or differences in the likelihood of of hospital admissions, which we could not explore in this hospital-based group, ‘the researchers wrote.

“Finding B.1.1.7 more commonly in younger versus older people gives a subtle indication of more serious illnesses when patients with B.1.1.7 are admitted to hospital more frequently compared to patients with other genital lines, although the difference in disease under B.1.1 .7 was not found in this hospital in the main analysis. ‘

‘This study contributes to the consensus that B.1.1.7 has increased portability’

The Lancet Public Health study included data on 36,920 people who reported testing positive for Covid-19 and recording their symptoms between September 28 and December 27 in the COVID Symptom Study app.

The app – designed by doctors and scientists from King’s College London, Guys and St Thomas’ Hospitals and Zoe Global Limited, a healthcare technology company – helps track the spread of Covid-19 and the range of symptoms followed.

The authors of the study, based in the United Kingdom and the United States, analyzed the data reported in the app along with Covid-19 surveillance data for the United Kingdom.

The analysis showed that the occurrence of the B.1.1.7 variant in certain regions and over time is not related to changes in Covid-19 symptoms reported in the app, or the duration of the symptoms.

“The proportion of users with asymptomatic disease did not change significantly as the B.1.1.7 variant increased in incidence, consistent with other studies on the subject,” the researchers write in the study. “We also found no changes in the hospital admission; other reports have shown that the B.1.1.7 variant increases admission to the hospital.”

The researchers found that the rate of coronavirus re-infections was low – with 0.7% of app users testing a positive Covid-19 test again after 90 days – and that there was no evidence of increased re-infection rates. related to the B.1.1 .7 variant.

The researchers have no data on the risk of dying from Covid-19, and most of the app users are only tested if they have symptoms, and there were relatively few asymptomatic infections in the data.

Nevertheless, the researchers found an ‘increase’ in the reproduction number of the B.1.1.7 variant, suggesting that it may spread more easily.

“This study contributes to the consensus that B.1.1.7 increased portability, which greatly contributed to the sharp increase in cases in the UK during the study period and beyond, as well as continuous third waves in European countries with growing burdens. of B.1.1.7 cases, “Britta Jewell, of Imperial College London, wrote in an editorial accompanying the new study in The Lancet Public Health magazine. Jewell was not involved in the new study.

“Although B.1.1.7 has similar symptomatology to that of other generations, the emergence of new variants is inevitable as long as the SARS-CoV-2 transmission continues on a large scale,” Jewell wrote. “In other regions – especially in low-income and middle-income countries that wait longer to control their epidemics through vaccination”, methods to monitor symptoms and disease characteristics in real time, similar to the COVID symptom study, can help identify avoid potentially significant changes in symptomatology, transmissibility, mortality or vaccination as early as possible. “