It is expected to be a big week for COVID-19 boosters. Millions of people who got Moderna and the Johnson & Johnson vaccines could be eligible for a booster by the end of the week.

First, the Food and Drug Administration must give a full approval for the booster shots. An FDA advisory panel met last week and gave the go ahead for authorization of the booster shots. Now, regulators are expected to follow suit, which means the full approval may come within days.

Similarly, the Centers for Disease Control and Prevention advisory committee is set to meet Wednesday and Thursday to discuss the issues of booster shots for both Moderna and Johnson & Johnson. Then, the CDC director must sign off on the decision.

The Johnson & Johnson vaccine booster is being recommended for those 18 and older who received the first dose. Meanwhile, the Moderna vaccine booster is recommended for those 65 and older and those who are immunocompromised.

The broader age range for Johnson & Johnson is because the first dose was found to be 74% effective. A second dose brings it up to 94%.

If a decision is made by both panels in favor of the boosters, they may be available for people to receive by the end of the week.