Can This New AstraZeneca Drug Really Prevent COVID-19?

The short answer is no, as it is not designed to prevent a COVID infection. But the longer answer provides more details and interesting scenarios to consider. So let's dive in!



What exactly is this drug?


AstraZeneca, at the time of writing this, is seeking Emergency Use Authorization to release this prophylactic labeled as AZD7442. It is a combination of two long-acting antibodies called tixagevimab (AZD8895) and cilgavimab (AZD1061). These are provided to a patient in two sequential intramuscular injections, which are made up of 150 mg of each antibody.


The media and many other people make claims about AZD7442 that are not accurate, so I will discuss them upfront.


AZD7442 is not a vaccine, it is an antibody compound. It does not teach your body how to defend itself against COVID-19, but instead contains it to prevent it from causing a severe infection.


Also, AZD7442 is not a "pill" but a set of injections. This confusion is understandable, however, as pharmaceutical company Merck just recently also came out with an oral pill (molnupiravir) meant to do the same basic thing as AZD7442. While I might mention molnupiravir in this article, it is mainly to mention it as a similar treatment to AZD7442, and not as a review of molnupiravir itself.


Is AZD7442 effective at preventing COVID-19?


As I mentioned above, the answer is "no." Not because AZD7442 is not effective, but because it is not designed to stop a COVID-19 infection. This cocktail is only meant to reduce the symptoms that an infection would cause, meaning that you will still be infected, but the symptoms of it would be far more minimal, which may also translate to being less transmissible.


The benefits of AZD7442 come in relation to people who are immunocompromised and ergo cannot receive a vaccine. This is also beneficial to someone who may have gotten the vaccine, but due to their biology or other factors, may need a booster shot to help prevent hospitalization and/or death.


AstraZeneca has completed various trials with AZD7442, with the latest one called PROVENT phase 3. This was a randomized, double-blind, placebo-controlled, multi-center trial involving almost 5200 participants. 75% of them, who were all over the age of 18, had various comorbidities that made them more likely to catch COVID and get more severe symptoms if they did catch it.


This trial found that participants had a 77% less chance of developing COVID-19 symptoms. Of the 23% that did develop symptoms, none had severe symptoms. This treatment is believed to last for several months up to a year.


But what about other issues involving COVID-19, like late COVID? Let's find out.



AZD7442, Molnupiravir, and Long COVID


In my last post, I discussed long COVID and how it can have a debilitating effect on anyone who suffers from it. I also mentioned how getting the vaccine can prevent long COVID from even happening. But when it comes to the use of prophylactics, the question of its impact on long COVID is up in the air.


However, due to the fact that these antibodies are meant to contain the virus, as opposed to fighting it, there is a possibility that long COVID might still be on the table for many people who take this instead of vaccination. The reason I bring this up is to mention that prophylactics like this are not a viable alternative to a vaccine for people who are otherwise healthy.


Drugs like AZD7442 and molnupiravir are very important for the millions of people who have compromised or defective immune systems. As well as for people who are older, or have other comorbidities. It will be interesting to see how these and other treatments and boosters will work out over the next few years.


A good video on the topic can be found below by surgeon Dr. Vuong: