Covid-19, Ontario expands eligibility for fourth vaccine dose but epidemiologists are divided

TORONTO – Like Europe, Ontario also opens the vaccination campaign for the fourth dose, but expanding the audience: all adults aged 18 and over (in Italy, the administration of the fourth dose will currently concern people over 60 and fragile). It was announced today by Dr. Kieran Moore, Ontario’s Chief Medical Officer of Health, who underlined that the campaign will start immediately: it will be possible to book an appointment using the provincial health system starting from tomorrow, July 14, at 8am for all those who received the third dose five months ago or contracted the virus three months ago. 

Moore said, however, that people who do not have health problems “don’t need” to get vaccinated: healthy adults can wait until autumn, when a “bivalent vaccine may be available”, Moore said. “While we are making this option available, it is important to note that healthy individuals currently vaccinated continue to have significant and persistent protection against serious Covid-19 disease even six months after the last dose”, he said. “However, there may be individuals with personal or medical circumstances who may wish to benefit from the additional protection of a second recall”.

Moore also said that personal circumstances may also play a role in determining whether an individual chooses to get the second “booster”. Healthcare professionals and those working in crowded environments should also receive the fourth dose, as should people with at-risk family members. In any case, anyone with questions about whether or not to receive a fourth dose of the vaccine is invited, by the provincial health authorities themselves, to contact their doctor.

But Ontario epidemiologists are divided on whether to offer the fourth dose as early as this summer. In fact, just over four million people have received two doses of the Covid-19 vaccine and have yet to receive the third. And in any case, the positions are different, if not opposite. Dr. Susy Hota, medical director for infection prevention and control at the University Health Network, told CTV last week that you shouldn’t expect more vaccines that might target specific variants or sub-variants as it is more important to reduce suffered the risk of severe symptoms and disease-related death.

Instead, Dr. Dale Kalina, an infectious disease physician, told CP24 that there isn’t much benefit from fourth doses unless an individual has a compromised immune system. “People who really need booster doses, in general, are people whose immune systems don’t work particularly well. So people who are over 70 or those who are taking drugs that suppress the immune system”.

The launch of the fourth dose vaccination campaign for all over 18s comes at a time when Ontario is in the midst of the seventh wave of the pandemic, “with an expected peak in the coming weeks”, Moore said. Ontario has seen a sharp increase in the presence of the virus in wastewater, as well as an increase in the rate of positivity and hospitalizations in recent weeks “but there will be no new restrictions”, Moore pointed out.

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