TORONTO – One dose of one vaccine, one of another: when in the absence of available alternatives at the time of recall, injections of different vaccines were offered, many people accepted. After all, the scientific community tried to reassure everyone, the benefits would have been the same. Then, slowly, the effectiveness of a mixed vaccination regimen was questioned. Or at least doubts have arisen for lack of an experimental basis on which to base the decision. And many countries in the world have decided not to authorize, for example, vaccines such as AstraZeneca, called into question for the risk of developing thrombotic events such as heart attacks and pulmonary embolisms.

But what to say to those who have now received a dose of AstraZeneca and a second of Pfizer or Moderna? Beyond the coverage, which is hopefully the same if not higher than that given by two identical vaccines, the problem of recognition remains when undertaking international trips. The government, with decisions and counter-decisions, with certainties that soon become doubtful, has done nothing but generate confusion and problems on the skin of the citizens. What until a minute before was a conviction, becomes, in the blink of an eye, disorientation, doubt, insecurity. Now, to run for cover, Ontario has asked the federal government to ensure that when border measures are lifted, the validity for international travel of mixed Covid-19 vaccines received from Canadians is recognized.

To write to the Minister of Intergovernmental Affairs Dominic LeBlanc were the Minister of Health Christine Elliott and the Solicitor General Sylvia Jones: Ottawa, they put in black and white, “must collaborate with the World Health Organization (WHO) to update the guidelines to international partners, recognizing mixed vaccines as a complete and accepted vaccination regimen”.
Ontario and other Canadian provinces offered residents the option of either giving an injection each of the Pfizer-BioNTech and Moderna vaccines or making an mRNA injection after the first of the Oxford-AstraZeneca vaccines.

Ministers say it is critical to “integrity and trust” in Canada’s and Ontario’s vaccination programs that people who have received doses of two different vaccines are considered immunized abroad.

In addition, Elliott and Jones argue that the Oxford-AstraZeneca vaccine, which is not approved by the US Federal Drug Authority, should be considered internationally valid.

But while Ontario is clearly demanding that the federal government request WHO to recognize the combination of two doses of different vaccines, Quebec tries to get around the obstacle by offering an extra dose of mRNA vaccine to people who want to travel to countries that do not recognize their vaccination status.

The Department of Health said a third dose was made available because some countries do not consider people to be fully vaccinated if they have received a mix of Covid-19 vaccines. “The administration of an additional dose of vaccine remains an exceptional measure for people who have planned an essential trip out of the country, in the short term, and who must meet vaccination requirements,” the department said in a statement.

What is worried is that after being invited to be administered different vaccines, the citizen is now abandoned to his fate: it is up to the person who has already received the two doses of vaccine to assess the risk and seek the advice of his doctor before being inoculated with a third extra dose of Pfizer-BioNTech or Moderna vaccines. The additional dose, say the Department of Health does not necessarily provide greater protection than two doses. “The person should be adequately advised about the potential risks associated with this dose in addition to the benefits of the planned trip – said Robert Maranda – everyone should weigh the relationship between risks and benefits”. Which translated into simple words means: do as you wish, naturally at your own risk.