An ongoing bird flu epidemic has forced farmers to kill millions of egg-laying hens, leading to a serious shortage. The low supply of eggs means customers end up paying quite a bit more than usual at the supermarket. In some places, eggs now cost more than double what they did six months ago.

The average price of a dozen large, grade-A eggs was $4.15 in December, up from $3.65 in November, according to the Bureau of Labor Statistics. Egg prices were also up more than 36% year-over-year in December, according to the Consumer Price Index.

Avian influenza has led to a shortage of eggs and wholesale prices that are through the roof. Consumers can expect to feel the pain for a while.

“We’re just coming out of the highest demand season of the year—the winter holidays—when eggs sales increase significantly due to holiday baking and entertaining,” she says. These two forces combined—tight supply and high demand—are directly causing the spike in wholesale prices consumers are seeing.

Eggs prices are sky-rocketing. If your wallet is feeling the price hike, here's how you can replace them with plant-based ingredients.