Tag Archives: flu shot

Vegan Flu Shots: A Guide

Flu shots can be a difficult topic in the vegan community. The internet has a lot of misinformation about vaccines in general, and flu shots in particular, which can make the topic controversial in the best of situations.

In a vegan context, the conversation is complicated by the fact that flu shots are generally made with eggs. This leads to heartache, as people have to choose between what’s best for their own and their family’s health, and being true to values that they have worked hard to live by. This can lead to motivated reasoning, where people may choose to believe that vaccines are ineffective or unsafe, rather than face the ethical dilemma.

I think it’s important to foster appreciation for science and objectivity within the vegan community, even when that means facing facts that we’re not wild about. Flu shots are a safe, effective technology, and we should seriously consider getting these vaccinations, even though they are generally not vegan.

Why should I get a flu shot?

Flu shots are associated with better performance in a broad array of health outcomes. Flu shots provide about 50% protection against getting the flu in any given year. (That is, vaccinated people get the flu half as frequently as those who are not vaccinated.) While this is less than the complete immunity given by some vaccinations, it still makes a meaningful difference to individual and community health.

The flu is particularly damaging to groups at high risk of flu complications, such as young children, the elderly, pregnant women, and people with various chronic diseases. (The CDC has a comprehensive list online.)

It’s important to recognize that vaccinations, flu and otherwise, are not a strictly personal decision. Your choice to vaccinate or not affects those you come into contact with, and society more broadly. Even if you are not at high risk of flu complications, some of those that you come into contact with may be. By getting a flu shot, you are helping to protect your community members.

Why aren’t flu shots vegan?

Influenza viruses only grow in animal tissue, which means that animal products are required to produce them. The standard method of producing vaccines involves growing the virus in fertilized eggs. The CDC explains:

These vaccine viruses are then injected into fertilized hen’s eggs and incubated for several days to allow the viruses to replicate. The virus-containing fluid is harvested from the eggs. For flu shots, the influenza viruses for the vaccine are then inactivated (killed), and virus antigen is purified. [1]

The final vaccine is the isolated antigen — the virus proteins that the body recognizes as foreign, and develops an immunity toward. It’s these proteins, rather than the virus itself, that results in immunity.

Are there any alternative methods of making flu shots?

Yes! This is an area where there has been a lot of recent progress, partly because the existing egg-based production system is slow and difficult to scale. Because the technology has changed so quickly, vegan communities may not be up to date on the new flu vaccines.

In 2012, a “cell-based” flu vaccine was approved. This vaccine strategy still uses eggs to grow an initial virus culture, but uses cultured animal cells to grow the the much larger amount of virus needed for vaccination. This avoids the majority of the egg use in the vaccine production process. At time of writing, there is only one cell-based flu vaccine in the US: Flucelvax. [1]

In 2013, a recombinant flu vaccine was approved. This strategy does not use eggs at all. Instead, the virus protein that triggers immune response is isolated, and genetically added to a virus that grows well in vitro on cultured insect cells. Once the virus has grown, the antigen is filtered out as usual, producing a vaccine. There is one recombinant flu vaccine approved in the US: FluBlok. Just last month, the FDA expanded its approval to cover all adults over 18 years old. (Previously it was approved for adults ages 18-49.) [1]

There continues to be a lot of research in this area, and I came across research toward plant-based recombinant flu vaccines while writing this post. It seems likely that vaccines will be more vegan-friendly in the future, in order to solve some of the technical limitations of egg-based vaccines.

So are these vegan?

Yes, more or less.

I’m comfortable calling the FluBlok vaccine vegan. I haven’t verified that its production uses no animal products, however this vaccine strategy does not require animal products fundamentally. Regardless whether it is strictly vegan, it is moving vaccines away from using eggs, which is something I’m happy to support.

I also think that Flucelvax worth supporting. Even though Flucelvax it is arguably not vegan (since it participates in the CDC process of delivering virus grown in eggs to vaccine manufacturers), the cell-based approach has different strengths and weaknesses compared to the recombinant approach, and this approach could easily lead to effective vegan vaccines in the future that could overcome potential weaknesses of the recombinant approach. (More on this below.)

I think that vegans should get flu shots, including conventional flu shots when vegan versions are not available or are not medically appropriate for them. Vaccines save lives, including the immunocompromised and those who cannot get vaccines for medical reasons. We can all help them by getting vaccinated. If you’re able to get one of the new vaccines, you can participate in moving the science forward toward vegan solutions.

Which flu shot should I get?

This information keeps changing, so check with the CDC for up to date information. I’m not a medical professional, but I’ll summarize the information I’ve found from the CDC and elsewhere, on some reasons to consider each vaccine type:

Recombinant / FluBlok

Adults 18 years of age or older can get FluBlok vaccines.

Since FluBlok contains only individually selected coating proteins from the flu vaccine, there is some concern that this vaccine strategy may be less effective. By contrast, if a vaccine contains whole virus particles (as in either conventional or cell-based vaccines), then your immune system can form antibodies to any of the virus’ proteins, rather than the selected few that recombinant vaccines contain. This may make this strategy more risky, so high-risk individuals may opt for other vaccine types.

Other considerations: This is a relatively new vaccine type, so we know the least about its efficacy. While the CDC says that many people with egg allergies tolerate even conventional vaccines, FluBlok is the only vaccine that contains no egg allergens.

I’m a reasonably healthy adult at low risk of flu complications, and I don’t have any young children in my household, so I chose this vaccine.

Cell-based / Flucelvax

Adults 18 years of age or older can get Flucelvax vaccines.

The cell-based vaccines should be equivalent to conventional vaccines, and are expected to be similarly effective. The only difference is how they are produced. They may be a good choice for adults who are at risk for flu complications, and are not comfortable with recombinant vaccines.

Cell-based vaccines are likely to have less egg allergen than conventional vaccines.


Children from 6 months to 18 years of age should only get conventional flu shots. Children are at high risk of flu complications, and the newer flu vaccine types are not approved for them.

Conventional flu shots are a very well established and studied technology, so may also be a good choice for those at high risk for flu complications, or those who are not comfortable trying a newer type of vaccine.

How do you get a vegan flu shot?

I chose to get a FluBlok vaccine this year. It’s the newest and most high-tech vaccine, and I wanted to find out how difficult it would be to get.

I’m also excited by using recombinant genetic techniques to produce vaccines as a technology. I think this technology could do a lot of good for society (faster vaccine turnaround times, more efficient scaling of vaccine production), as well as removing animals from this sphere of medicine. This would be similar to how recombinant genetics were used to produce insulin from bacteria, instead of harvesting insulin from slaughtered animals.

Finding a clinic

Update: I’ve posted an updated guide to getting a vegan flu shot in 2015. Notably, Flublok can now be found in Target Pharmacies.

One widely available source of FluBlok vaccines is Passport Health. Passport Health is a chain of vaccination clinics that specialize in travel vaccines, all of which offer FluBlok given a few days notice. San Francisco has a Passport Health clinic, so I chose that.

More recently, I’ve learned that you can find clinics that offer FluBlok (and other vaccines) online at http://vaccine.healthmap.org/. To find FluBlok, go to the Vaccine Finder site, uncheck all the vaccine types, then check only “Recombinant Flu Shot” within “Flu”. Enter your address, and it will list clinics that have registered as carrying it.

According to Vaccine Finder, there are two additional clinics that carry FluBlok in SF: Pharmaca in Cole Valley, and Recharge Medical & Day Spa in Nob Hill.

Note that Passport Health is not found by Vaccine Finder, so you’ll have to check for Passport Health locations separately for now. FluBlok’s website also has a list of clinics that offer FluBlok by state, however this list seems to be out of date, and did not contain either clinic listed in Vaccine Finder, nor any Passport Health locations, so I don’t think that list is very useful. For the time being, you’ll have to do a few searches to find the FluBlok clinic nearest you.

Making an appointment (at Passport Health)

It took about a 10-15 minute phone conversation to schedule an appointment and go through their triage to determine whether getting a flu shot was appropriate.

Note that the triage questions are generic, and seem to be the same for all flu shots. Specifically, they will ask you about egg allergies. That doesn’t mean that FluBlok contains eggs, or that they’ll give you the wrong vaccine. It’s just on their list of flu shot questions to ask.

I scheduled an appointment for a few days out, since Passport Health orders FluBlok as needed, rather than keeping it onhand.

Once you schedule an appointment, there’s an online health information form to fill out, which takes another 10-15 minutes. Just basic health and medical background.

Office visit

In SF, the Passport Health clinic is in a shared office building, in the vicinity of Fisherman’s Wharf. (Near Pier 31, if that means anything to you.)

The clinician met me in a shared reception area, and led me through a maze of identical-looking office doors to the Passport Health office. A few more questions, and we were on our way.


What all the fuss was about

The shot is just like any other flu shot. It makes your arm sore for a while, but otherwise is fine. The clinician let me take some pictures, and was accommodating and friendly, if slightly confused as to why I wanted photos of the vaccine bottle.

What does it cost?

The appointment, including the FluBlok vaccine, cost $30 total. That price seems to be very consistent online. I didn’t bother with submitting it to insurance, so I don’t know what the odds are of getting it covered.

Final thoughts

Medicine in general is not fully vegan. I recommend following medical advice in general, even when the medicine isn’t vegan, until vegan versions are available. For young children, this means getting conventional flu shots until the alternative preparations are approved for all age groups.

However it’s exciting to see flu shots making this transition away from egg-based production. The new high-tech immunizations could have real benefits beyond the vegan community. They take less time to develop and produce at scale, and could respond more quickly to mutations, or to new strains as they emerge.

We can participate in pushing medicine forward in this direction by opting for the newer flu shot preparations. The more people get the vaccine, the more safety data we gather, and the more trust we can have in the safety and efficacy of the new process. I’m happy to have participated in that process, in a small way.

This is also a good example of using genetic modification to solve a problem (growing virus antigens for a vaccine) that couldn’t otherwise be solved without chicken eggs. This is a great use of recombinant genetics, and is an example where the vegan community could embrace this technology.

So get a flu shot! If you’re a healthy adult, consider getting FluBlok or Flucelvax if they are available. Otherwise, just get a regular one. There’s a good chance that vegan flu shots will be widely available in the next few years.

Epilogue: Why recombinant vaccines might be more effective

Recombinant vaccines might overcome some of the limitations of the egg-based vaccine production process. To illustrate this, let’s consider the 2012-2013 flu season.

Since the flu mutates quickly, researchers have to make educated guesses about which strains will break out ahead of time, and prepare a vaccine for those strains. Sometimes they get this wrong, which is why the flu shot is only about 50% effective.

In the 2012 flu season, an interesting situation emerged where the flu vaccine was less than 50% effective (and only 9% effective in seniors), yet the scientists had guessed correctly — 90% of flu viruses were a match for the vaccine. So why wasn’t the vaccine working?

The main flu virus that season was an H3N2 strain, and H3N2 flu viruses do not grow effectively in chicken eggs. To get flu viruses to grow well in eggs, immunologists “reassort” the virus they want to target with flu virus strains they already have that are known to grow quickly in eggs. This involves infecting eggs with both viruses at the same time, and filtering out viruses that don’t have the target virus’s antigen proteins. (A more detailed discussion of this process can be found here.)

It appears that the 2012 vaccine lost its efficacy during this reassorting process, resulting in an H3N2 vaccine component that did not protect against that year’s H3N2 strain.

Either a recombinant approach (like FluBlok) or a cell-culture growth process (like Flucelvax) would not require adapting flu viruses to grow quickly in chicken eggs, and should not be vulnerable to this mode of failure. Cell-culture processes (like Flucelvax) might be the most resilient to this type of failure, since it does not require modifying wild viruses at all, unlike both recombinant vaccines and conventional “reassorted” vaccines.

Post-epilogue: This year’s vaccine

The 2014 flu vaccine is having difficulty for another reason: the wild virus has mutated, and it would take too long to manufacture a new vaccine. Faster vaccine production technologies (including recombinant or cultured production methods) may help us respond more quickly to virus mutations in the future.


  1. Centers for Disease Control and Prevention, How Influenza (Flu) Vaccines Are Made. (Accessed Nov 4th, 2014)
  2. Nature (News), Mutations explain poor showing of 2012 flu vaccine. (Accessed December 28th, 2014)