We certainly do not want people to suffer the consequences of any of the illnesses for which we have preventative vaccines, including influenza. Much of what fuels vaccine hesitancy in general is misinformation and what I believe is a general “short memory” with respect to the effects and symptoms of vaccine-preventable infectious diseases. The vaccines we have used for many years to prevent diseases such as chickenpox, measles, and influenza have, in fact, been successful in preventing illness, leading to the possibility that some individuals may forget how bad certain illnesses can be, and thus may not feel an urgent need to vaccinate themselves or their children. Having said that, influenza has its own set of vaccine hesitancy issues. For instance, in addition to many people not believing that they need this particular vaccine, it is a vaccine that must be administered every year. Further, it does not confer 100% protection. This is, in part, because there needs to be a good match between the influenza virus strains contained in the vaccines being administered and the influenza strains that are circulating, and also because individuals of different ages or with different underlying medical conditions may have different responses to the influenza vaccine. Misinformation results in the mistaken perception that the vaccine is ineffective, or that it can make parents or their children ill. It is extremely important to address parents’ concerns openly and to ensure that individuals who need to make the decisions regarding vaccination fully understand the facts about the vaccines (eg, that there is no better way of preventing influenza than through vaccination). Personal experience can also be helpful—those who have had influenza would never want to get it again. Hopefully, when parents can see a vaccine-preventable illness such as measles spreading in a community or region among unvaccinated and poorly vaccinated populations, there will be more acceptance of all vaccines, even among vaccine-hesitant parents. We saw more acceptance during the 2009 influenza pandemic. In fact, some parents have become vaccine advocates after witnessing the potentially devastating effects of influenza on otherwise healthy children.

Before California instituted legislation a few years ago, the state had a steadily increasing rate of vaccine exemptions, which illustrates the increasing level of vaccine hesitancy in our community for the previous 10 years. The rate of vaccine exemptions just kept rising to the point where we started to see more outbreaks of disease. But vaccine hesitancy is not just an issue in California or even just in the United States, for that matter. The World Health Organization declared vaccine hesitancy and a global influenza pandemic as 2 of the top 10 threats to global health in 2019. The list of reasons that parents cite for being concerned about vaccines is long. Most of the things on that list are concerns they have about adverse events from vaccines, ranging from minor fever and swelling and febrile seizures, to more concerning events that have been inappropriately linked to vaccines, such as autism. 

Fundamentally, it boils down to an inaccurate risk-benefit estimate—parents underestimate the risk of the disease and they overestimate the risk of the vaccines. As Dr Muñoz mentioned, because vaccines have been so successful, parents often do not “see” the disease. But the invisible threat of infectious disease has the potential to explode at any point and cause widespread outbreak, and we saw that with the measles outbreak over the last year, with the greatest number of cases reported in the United States since 1992. These outbreaks of measles, occurring right in pockets of vaccine hesitancy, illustrate so profoundly how quickly these infections can resurface in a community. A subset of these vaccine-hesitant parents also believe that their personal freedoms are being impinged upon by vaccine requirements. These parents see themselves as exercising their civil liberties by refusing vaccines or by not following guidelines for vaccination. And all of this is fueled by the Internet, which allows inaccurate information to flow quickly around the community. 

It is our responsibility to make sure that parents have accurate information. The simplest way to do that is to encourage them to talk to their child’s physician about their concerns and to be open to having a discussion about the risks and benefits of the diseases and the vaccines. There is also a plethora of credible websites with good information about vaccines, including the Immunization Action Coalition (www.immunize.org), HealthyChildren.org from the American Academy of Pediatrics (www.healthychildren.org), the Children’s Hospital of Philadelphia (www.chop.edu/centers-programs/vaccine-education-center), and the Centers for Disease Control and Prevention (www.cdc.gov/vaccines/index.html). We can continue to promote them as sources of accurate information for parents as they are making these decisions.  

I agree completely that the amount of inaccurate information on the Internet that parents are reading and believing is a serious concern. In addition to the fear of developing autism and other neurologic problems, parents are often concerned about overwhelming their child’s immune system. They believe that there are too many serious adverse reactions associated with vaccines and that getting a disease naturally is better than getting a vaccine. The importance of engaging in conversations about these issues with parents to provide them with accurate information simply cannot be stressed enough. It is vital to discuss the safety and effectiveness of vaccines, including why vaccination is important for preventing diseases and complications that parents may not have seen firsthand, but that can easily re-emerge as vaccination rates drop.

Unfortunately, as infectious disease specialists, this is the scenario we are finding ourselves in all too often: A pediatric patient presents to the hospital seriously ill from influenza and ends up getting a bacterial superinfection. The parents say, “We were offered the influenza vaccine and we did not take it because we did not think that it was important. We did not think that our child was at risk for this disease, and now we see that this was not the case.” It is important for physicians to explain to parents the fact that all of these infectious diseases do have complications. Younger children, especially those under 2 years of age, are at higher risk for complications and hospitalizations, especially from influenza.