An Ontario infectious disease specialist says the province’s decision to move ahead with second doses of the Oxford-AstraZeneca COVID-19 vaccine is the “right call.”
Dr. Lorne Small with Trillium Health Partners says risk of adverse reactions to any of the current vaccines is low and typically comes after the first dose and not so much the second.
“This (AstraZeneca) is a very effective vaccine and the risk of an adverse effect is low,” Small said.
“The benefit far outweighs any risk.”
A number of provinces put a pause on the vaccine over concerns of a rare, fatal blood clot. However, on Friday, Ontario’s Medical Officer of Health Dr. David Williams said new data indicated health risks posed by the vaccine are low.
Dr. Ishac Nazy, associate professor and principal investigator with the McMaster Platelet Immunology Laboratory, says the risk of getting one of the reported blood clots from the vaccine is about one-in-600,000, according to the last U.K. study.
The likelihood of getting some side effect from the vaccine is about one-in-60,000 from the first dose, and the odds are even fewer of a reaction from the second shot, according to Nazy.
About 1,300 adults are set to participate in a number of clinical trials across Canada to investigate the effects of mixing COVID-19 vaccines for the first and second doses in response to the AstraZeneca pause.
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Nazy says that study is addressing safety issues and whether the effectiveness of vaccines are compromised with mixing different types, such as mRNA with viral vector vaccines.
“Theoretically, in immunologically, several researchers and experts have suggested that you might even get a better immune response when you mix because it’ll involve different branches of the immune system,” Nazy said.
Over 7.7 million doses of COVID-19 vaccines have been administered in the province as of Friday, with Hamilton Public Health reporting over 266,000 of the doses were put into arms by city health care workers.
About 52.2 per cent of the eligible population in the city over 18 have received at least one dose as of Thursday.
Dr. Small says the province’s decision to green light some outdoor activities amid the ongoing stay-at-home order is a good idea based on recent scientific data that suggests very low transmission rates person to person.
However, it’s not a certainty and the relaxing of amenities should not be misconstrued as a “free for all.”
“It is safer outdoors, but we still need to be respecting public health measures in everything we’ve put in place so far,’ Small said.
“I think doing it slowly is the right way to go.”
Hamilton reports 107 new COVID-19 cases, infection reproduction number increases
Hamilton reported 107 new COVID-19 cases on Friday and an increase in the city’s reproductive number which was over 1.0 – suggesting spread of the virus within the community.
Public health says the reproductive number moved from .82 as of Thursday to 1.03 on May 21 — signifying that the average number of people an infected person is passing COVID-19 on to.
The city’s seven-day moving average of cases was at 116, last reported on May 19.
The percentage of Hamilton tests returning from Ontario labs as positive for COVID-19 is 8.4 per cent, above the province’s last reported daily number, 5.4 per cent as of May 21.
There are four new outbreaks in Hamilton at a pair of workplaces and two daycares.
Two outbreaks on the Mountain include Bar Hydraulics Inc. and Acura of Hamilton which have four and two cases respectively involving workers.
Church of St. Peter’s Children’s Day Care Centre in central Hamilton has five cases among patrons, while Tiny Hoppers Early Learning Centres in Stoney Creek has cases among three workers and a pair of patrons.
Six outbreaks were closed on Thursday at the Mission Services overflow shelter in east Hamilton, the CLS Retirement Home, St. Thomas More Children’s Centre, Beckfield Building Training Centre, Noah’s Ark Children’s Centre and Adlers Tile & Carpet Co.
The largest of the outbreaks was at the CLS retirement home which had 12 cases among seven patients and five workers.
The city has 38 reported outbreaks tied to 447 cases, 18 are in workplaces and involve over 120 people.
The city’s active cases are still under 1,000 as of Friday, down by 18 to 952 day over day.
There are 91 patients with COVID-19 in Hamilton hospitals as of May 21. Hamilton Health Sciences says they have 59 patients, with 24 in intensive care units (ICU) and St. Joe’s 32 patients, with 26 of those in an ICU.
St. Joe’s says its ICU occupancy rate is now at 144 per cent as of Friday, while HHS facilities are at 124 per cent.
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