Can 'Mix And Match' Vaccination Boost Immune Response?

It has been made clear that people receiving COVID-19 vaccinations need to stick with the same company for both shots, when applicable. But new evidence is suggesting that it's worth looking into mixing and matching vaccines. Here's what you should know.

According to NPR, using two different vaccines is referred to as heterologous vaccination. While the concept isn't new, there is normally a reason that scientists recommend doing this. In the case of the COVID-19 vaccine, issues with side effects and the vaccine shortage have both contributed toward the idea of mixing and matching doses.

The reason why heterologous vaccination often works well makes a lot of sense. Vaccines work by essentially showing our immune systems something that looks like the virus we want it to fight off. Our bodies then use that information to prepare for the real thing if it ever comes along (via World Health Organization). Each vaccine is created a little differently, which means the Moderna vaccine is going to show your body a slightly different image of the COVID-19 virus than the Pfizer vaccine. This is also one reason that side effects will vary slightly between vaccines.

Mixing and matching vaccines is essentially like giving your immune system two different images or pieces of information to fight the same virus. Theoretically, the more it knows, the better.

"If you give two different types of vaccine, then you tend to get a better immune response than if you give the same vaccine twice," Helen Fletcher, a professor of immunology at the London School of Hygiene & Tropical Medicine, told NPR.

According to MIT Technology Review, government officials in Germany and France have already recommended that younger citizens get their second dose of the vaccine from a different company than the first. There are also multiple trials happening around the world that are testing the efficacy of doing this with different vaccine combinations.

For now, stick to your government's recommended dosage schedule. There isn't enough evidence to confirm that mixing and matching vaccines is the best strategy right now. However, it is likely that there will be more definitive information on this in the next few years.