The British Medical Association has warned that there will be a long delay between the injection of the first and second dose of the Pfizer / Bioentech vaccine because, in the opinion of its experts, a longer wait could reduce its effectiveness.
In the United Kingdom, as in Quebec, the strategy adopted by governments is to provide the first dose of the vaccine to a greater number of people, that is, to extend the time limit for a second injection to about three months. More specifically, in mid-January, Quebec recommended injecting a second dose of the vaccine within 42 to 90 days.
However, the head of the British Medical Association, Dr. Chand Nagpal, warned that the decision would have an impact on the vaccine and instead recommend limiting the time between two doses to six weeks or half. Currently assigned.
Citing a World Health Organization study that recommended delaying the injection of a second dose of Pfizer’s vaccine in exceptional cases, Dr. Nagpal described the strategy as “difficult to justify” in a letter to the BBC in a letter to the British government.
“After six weeks the defense will not be extinct, but what we do not know is what level of protection it will provide,” he told the BBC Breakfast show on Sunday. Stated to understand “compromise and reasoning”. This is the right thing to do, and we will see that other countries follow suit. “
However, there is a difference between the vaccine developed by Pfizer / Bioentech and the Oxford / Astrogenica developed in the United Kingdom. In the case of the Pfizer vaccine, the most widely used vaccine in Canada, the effectiveness of the vaccine depends on the administration of the second dose after just 21 days. Therefore, it is very difficult to know how effective this vaccine is after a period of 21 days and whether it is valid after 90 days.
Despite criticism from some experts in Quebec and elsewhere, Quebec’s head of public health, Horacio Aru, has at times defended the strategy. “We need to understand that we are in a pandemic and that there are people who are dying right now,” Horacio Rare, the national director of national health, told a news conference in early January. To save the maximum number of people in the short term, we hope it will significantly save lives, ”he said, believing that a single dose would“ still provide adequate protection ”.
Currently, an injection of the second dose is scheduled for March for people who have already been vaccinated.