HALIFAX-National Advisory Committee on Immunization (NACI) has provided new recommendations on vaccine interchangeability, stating that the types of COVID-19 vaccines should be consistent.

“NACI recommends using the same COVID-19 vaccine product as much as possible to complete the vaccine series. If a vaccine product for the previous dose is unknown or unavailable, a similar type of COVID-19 vaccine should be tried to complete the vaccine series.” According to a statement issued on Friday.

For example, the committee said that a vaccination series starting with one mRNA vaccine should be completed with another mRNA vaccine, and the series of vaccines should not be restarted. In contrast, NACI stated that if a second dose of the Oxford-AstraZeneca vaccine is not available, a single dose of Johnson & Johnson’s Janssen vaccine can be supplemented.

“If an individual receives one dose of AstraZeneca vaccine but cannot receive a second dose of AstraZeneca vaccine, one dose of Janssen vaccine (if any) can be used as the second dose to complete the vaccine series.”

The committee stated that there is currently no data on the interchangeability of COVID-19 mRNA vaccines.

The statement reads: “However, the spike protein encoded by any authorized mRNA vaccine is stabilized in the same way to remain in the pre-fusion conformation, although other vaccine components such as lipid nanoparticles and mRNA sequences may have The difference).”

The committee stated that there is no reason to believe that the use of other authorized mRNA vaccine products to complete the series of mRNA vaccine production will cause any other safety issues or insufficient protection.

According to the committee, currently, there are only data on the expected response to the combination of AstraZeneca and Pfizer-BioNTech COVID-19 vaccine.

The statement said: “After obtaining further evidence on the mixed COVID-19 vaccine schedule, a recommendation will be made to complete a set of vaccine series for individuals who have received a dose of AstraZeneca’s COVID-19 vaccine.”

The data is expected to be released in June.

Due to safety and supply considerations, several provinces have suspended the first vaccination of AstraZeneca.

On Friday, Ontario public health officials announced that they will provide the remaining AstraZeneca COVID-19 vaccine list to those waiting for the second dose of vaccine based on the preliminary results of the second batch of vaccines. A new study in Spain Indicates that the risk of adverse reactions is very low and cannot be continued.

Except in rare cases, the province will not provide AstraZeneca injections to anyone else. Nova Scotia, New Brunswick, Quebec, Manitoba and Alberta have yet to announce whether they will provide a second dose of AstraZeneca.