Interior Health explains the difference in booster shots and how to choose yours

KAMLOOPS — Health authorities across the province are ramping up the administration of COVID-19 vaccine booster shots, and confusion around the differences in each vaccine are raising questions.

A first and second dose of Moderna is .5 millilitres of solution. Pfizer, on the other hand, is .3 ml.

According to Interior Health, the total number of booster shots administered so far in Kamloops is 36,828.

But for those who haven’t gotten their booster yet, the varying measurements are causing mixed feelings.

On Thursday (Jan. 13), CFJC News was in downtown Kamloops talking to residents about how they feel about different brands of booster shots.

“Me, if I could choose the same one, I would. But if I can’t, I don’t know if I would,” said one woman.

“Personally, I didn’t get two different brands, but I don’t see anything wrong with that,” said a man.

“I know people are reluctant to have Moderna, for example, as a booster, but I don’t know that there really is a science behind that,” another man said.

Enter Dr. Carol Fenton — Interior Health Medical Health Officer — to explain the science behind it.

Fenton says that Pfizer has 30 micrograms of the spike protein MRNA code in each dose. Moderna’s vaccine has 100 micrograms. Both protect you from the virus.

Once health authorities had more experience with both vaccines, they were able to compare them.

“We saw that we got excellent protection from the 30 micrograms from Pfizer, and some people had better protection from the higher amount of MRNA from the Moderna, but other people had more side effects,” Dr. Fenton explained.

Some of those side effects caused by Moderna have been seen in younger people.

Like Myocarditis, the inflammation of the heart muscle, and Pericarditis, the inflammation of the outer lining of the heart.

“So Pfizer is a preferred product for those, because they’re young, they’re healthy, that lower dose of MRNA is enough to boost their immune systems,” said Dr. Fenton.

While Pfizer’s booster shot remains at .3 ml, Moderna’s booster shot is cut in half, to only .25 ml.

Interior Health says the dose was lowered to ensure that no matter which vaccine you received, the protection will be roughly the same.

Dr. Fenton continued, “The only difference is that they were formulated and manufactured by different companies, so that lipid envelope that helps it get into cells is slightly different, but we know that they both work.”

She says any vaccine combination is safe. So Dr. Fenton’s orders are: get the shot.