加拿大数据表明疫苗非常有效

gocanoeing

本站元老
注册
2006-11-21
消息
5,599
荣誉分数
1,066
声望点数
323
New data suggests Canada's 'gamble' on delaying, mixing and matching COVID-19 vaccines paid off

Early data suggests strong protection against delta, no evidence for boosters in the general population yet

New Canadian data suggests the bold strategy to delay and mix second doses of COVID-19 vaccines led to strong protection from infection, hospitalization and death — even against the highly contagious delta variant — that could provide lessons for the world.

Preliminary data from researchers at the British Columbia Centre for Disease Control (BCCDC) and the Quebec National Institute of Public Health (INSPQ) shows the decision to vaccinate more Canadians sooner by delaying second shots by up to four months saved lives.

The researchers excluded long-term care residents from the data, who are generally at increased risk of hospitalization and death from COVID-19, in order to get a better sense of vaccine effectiveness in the general population — and the results were exceptional.

The analysis of close to 250,000 people in B.C. from May 30 to Sept. 11 found two doses of any of the three available COVID-19 vaccines in Canada were close to 95 per cent effective against hospitalization — regardless of the approved vaccination combination.

That means for every 100 unvaccinated people severely ill in Canadian hospitals, 95 of them could have been prevented by receiving two doses of either the AstraZeneca-Oxford, Pfizer-BioNTech and Moderna vaccines, or some combination of the three.

Dr. Danuta Skowronski, a vaccine effectiveness expert and epidemiology lead at the BCCDC whose research laid the groundwork for the decision to hold back second doses based on the "fundamental principles of vaccinology," says the early data is extremely encouraging.

"We were very pleased to see during the period when the delta variant was not just circulating, but predominating, that we had such high protection nonetheless against both infection and hospitalization," the lead researcher on the analysis told CBC News.

"Protection was even stronger when the interval between the first and the second doses was more than six weeks apart."

In fact, the research showed that protection against COVID-19 infection from two doses of the Pfizer vaccine rose dramatically when the first and second shots were spread out — from 82 per cent after three or four weeks, to 93 per cent after four months.
...
 
顶部