Last Wednesday, the Food and Drug Administration (FDA) approved a fourth coronavirus vaccine. The latest shot is from Novavax and follows the traditional protein-based vaccine technology. For individuals who prefer this type of vaccine option or have an allergy to the ingredients of the messenger RNA vaccines, this has been a long-awaited arrival. However, experts don’t believe it’ll significantly impact the pandemic trajectory since two-thirds of Americans have already gotten their initial shots, and other companies’ doses are widely available.

Like other coronavirus vaccine manufacturers, Novavax is working on a revised version of their vaccine specifically designed to target BA.4 and BA.5 subvariants. The revamped vaccines from all companies are critical in the continuing fight against Covid-19. The strains, BA.4, BA.5, and BA.2.12.1, currently responsible for most infections weren’t in existence when the first vaccines were developed.

It’s vital to point out that the current vaccines have been essential in dealing with the pandemic. A recent study published in The Lancet states the first coronavirus vaccines saved 1.9 million American lives in their first year alone. Also, they still are protecting against severe illness and death from Covid-19.

The issue is the virus is continuing to mutate, and the latest variants have several changes to critical points on the spike proteins that make them less recognizable to immune systems than previous versions of the virus. To combat this, the vaccines must be slightly altered to best fend off the variants and given as a booster.

The process isn’t as simple as it sounds. First, experts need to predict which variants will dominate in late 2022 and into 2023. Next, they need to determine whether altered versions of the original vaccines will be effective. Then, the updated vaccines have to be tested to see whether they pose new challenges regarding safety, cost, or timely distribution.

This method is like what happens with developing the seasonal flu vaccine, which we still have trouble predicting which strain will be dominant in a particular season. The problem is that the new coronavirus is almost mutating faster than we can keep up with the changes, making developing effective boosters incredibly challenging. This difficulty is why many are wondering will the boosters targeting the current widely circulating variants be effective come fall, or will a new variant emerge between now and the expected surge of winter coronavirus cases?