If someone is having an allergic reaction, an EpiPen can help stop it, explains Gupta, but it does not offer "baseline protection" as Xolair would.
Allergist Jay Lieberman, a member of the board of Directors for the American Board of Allergy and Immunology, also stresses that critical point.
"The EpiPen is very different. It would still be used for an acute allergic reaction. But Xolair is a preventative drug. It has been shown to raise the threshold of reactivity to a point where you would worry less about accidental ingestions leading to reactions," he explains.
It's also important to underscore that Xolair functions with multiple food allergies, not just peanuts. That too is a step forward for those who are impacted by a variety of food sensitivities. Additional common food allergies include eggs, sesame, shellfish, cow's milk and wheat.
"Obviously it's not a cure, but it definitely gives you more peace of mind because it protects you should accidental ingestions occur. And it does that for multiple foods, not just one," says Gupta. "In this case, you have peace of mind for multiple allergies"
Long term implications
While the availability of Xolair represents important progress for those who suffer from Type 1 food allergies, there are also some questions that remain unanswered by the study Wood led, which was published in the New England Journal of Medicine.
The trial involved following 180 patients who had allergies to peanuts and two additional types of food, such as cashew, milk, egg, walnut, wheat and hazelnut. After 16 to 20 weeks of Xolair, study participants were able to tolerate small amounts of foods that had previously triggered an allergic response.
But because the study was limited to just a few months, it remains unclear how those with food allergies who rely on Xolair for prevention may fare over the long term.
"We don't know what happens if you go off of Xolair, or if you miss a dose," says Gupta. "Unfortunately, it's not a perfect treatment, but it's definitely a first step."
Because the study did not conduct a test challenge of foods until 16-20 weeks, it's also hard to say when exactly the Xolair becomes effective, whether that's immediately after the first injection, or sometime later.
"We did not look at what happens after one dose or two doses," Wood says. Though a separate study was previously conducted, he adds, on just 14 patients who were given one to two doses of Xolair and it "appeared to have its full effect." But he acknowledges that the question of when exactly Xolair starts working is important and needs to be studied further.
The bottom line, according to all three doctors, is that it will still be important for those who suffer from severe food allergies to carry an EpiPen. Similarly, the approval of Xolair does not mean those impacted can suddenly start eating foods they are allergic to.
"As of right now, the recommendation is you should still avoid the foods you have a reaction to and have your EpiPen with you," says Lieberman. "But if you actually eat something you're allergic to, your threshold will be so much higher before you will have a reaction."
Economics of Xolair
The FDA's approval of Xolair for food allergies brings another important benefit beyond the critical health implications. It also paves the way for US insurance companies to provide coverage of the medication, says Gupta.
The list price for the drug ranges from $2,900 (£2,300/€2,700) a month for children to $5,000 (£3,960/€4,600) a month for adults, according to the Associated Press.
Gupta says that for the Xolair approval to reach its full potential among those with food allergies, it's important to ensure that there are no disparities in who has access to the drug because of the cost.
"Now that the FDA has approved Xolair we need to make sure that all payers, including Medicaid, can cover it. We need to make sure everyone has access and that means we all need to work with policy makers so we don't face an accessibility gap," says Gupta.
For families like Youssef's, ensuring that products like Xolair are not cost-prohibitive can offer important relief from the day-to-day stress of living with a life-threatening allergy.
"Managing my daughter's allergy has been a journey of learning and adaptation for my family," says Youssef. "It's forced me to become an advocate for food allergy awareness and safety and to prioritise my daughter's health and well-being above all else…to ensure that my daughter can live a full and happy life while staying safe."
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