Ottawa Public Health’s advice on which COVID-19 vaccine to take for a second dose is the same as the advice offered for the first: take the first one you’re offered.
The local public health unit stressed the safety of mixing different COVID-19 vaccine formulations between first and second doses in a statement issued by the city on Thursday.
OPH pointed to guidance announced June 1 from the National Advisory Committee on Immunization (NACI) that signed off on the interchangeability of vaccines.
OPH’s recommendations pointed to the role of double-dose vaccine protection in staving off COVID-19 variants of concern. Waiting to get a vaccine that matches the same formulation as the first dose a resident received is not worth the delay, the health unit said.
The Delta variant of COVID-19, first identified in India, has spread rapidly in parts of the province such as Toronto, Peel and Waterloo. These areas have been prioritized for sped-up second vaccine doses.
Nine such cases have been recorded in Ottawa to date, with one new Delta variant case added this week.
OPH told Global News in a statement that the individual who tested positive for the variant was likely exposed during a recent trip outside the country and has self-isolated since returning.
“The best vaccine you can get is the first one that is available to you and a second dose of a COVID-19 vaccine is needed for the best protection against COVID-19 and its more transmissible variants,” OPH said.
The Moderna and Pfizer mRNA vaccines are made the same way and have similar effectiveness and side effects, the health unit said, making any added benefit between either formulation negligible.
Those who received the Oxford-AstraZeneca or other viral-vector vaccine as their first shot are cleared to take either the same shot or an mRNA vaccine as a followup, based on availability.
OPH said interchanging vaccines is not a new practice, noting that different products are routinely used to complete vaccine series for influenza, hepatitis A and other viral diseases.