Daily COVID-19 case numbers are down, but vaccination rates are also slowing. Unpacking reasons for COVID vaccine hesitancy reveals a few surprises.

While disappointing, it’s no big surprise that COVID-19 vaccinations are slowing down in the United States. The majority of people who intended to get a vaccine when it was their turn and had the ability to make it happen have gotten at least one jab. Logistical barriers remain, so making vaccination as easy as possible will help close the gap for those still wishing to be vaccinated. However, 15 percent of people surveyed in the most recent Kaiser Family Foundation report indicated that they wanted to “wait and see” before committing to vaccination. Among young adults 18-29 years old, nearly a quarter indicated they wanted to wait and see. I am particularly fascinated with this vaccine hesitancy group because they now control how this pandemic ends.

In order to allay concerns about vaccination we have to first admit that skepticism about COVID vaccines is a perfectly natural and expected response. From the speed at which vaccines were developed to the new technologies employed, it would be concerning for someone not to have questions. Ultimately though, where and how people find answers to their questions can have a drastic impact on whether concerns are alleviated or entrenched — shifting “wait and see” towards acceptance or rejection.

Alleviating concerns about speed of COVID vaccine development and the new technology involved:

First, COVID vaccine development got a huge head start because the virus that causes COVID-19 is closely related to common cold viruses and the viruses that caused SARS and MERS outbreaks. Years of vaccine research for those viruses yielded a wealth of information about its new cousin SARS-CoV-2 that was used during the pandemic’s infancy to quickly design vaccines.

Second, phase I, II, and III clinical trials for COVID vaccines were uniquely designed to overlap in order to crunch timelines without sacrificing scientific integrity — at great financial risk for the vaccine manufacturers. Normally a pharmaceutical company would not invest in a multi-billion dollar phase III trial until smaller phase I and II trials were completed and thoroughly evaluated. A process often taking years to complete. Additionally, the COVID vaccine trials took less time than expected to demonstrate efficacy because COVID was so rampant. Trials of vaccines against less common infections take longer because fewer people develop the disease.

In terms of safety, the approval process undertaken by the FDA was expedited, but only in terms of scheduling. No corners were cut in their reviews. The vaccines are “authorized” but not “approved” because it’s unknown how long immunity lasts. This information is typically included in the data package submitted to the FDA for vaccine approvals. It wouldn’t have been ethical to design a three- or five-year study for a COVID vaccine in the middle of the pandemic that had killed hundreds of thousands of people at the time. So the label “emergency use authorization” is more of a bureaucratic difference than an indication that the vaccines are not safe for approval. The vaccines currently used in the U.S. will undoubtedly receive full approval without any modifications, meaning that they are as safe in their authorized state today as they will be in their approved state ‘tomorrow’.

While it is true that messenger RNA (mRNA) is a new type of vaccine, research in this area is decades old. Thousands of people had been inoculated with mRNA for vaccinations and other medical uses in clinical trials prior to the COVID-19 pandemic, demonstrating both short- and long-term safety. And by now, hundreds of millions of people around the world have received an mRNA vaccine for COVID. Early trial participants are over a year from their inoculations and adverse events remain rare. If you are interested, I’ve written more about how mRNA vaccines work here and here.

What other factors contribute to vaccine hesitancy?

It may be easy to blame anti-vaccine/conspiracy theory campaigns for sowing mistrust in vaccines, but the type of vaccine hesitancy that I have personally witnessed has not stemmed from this realm. Instead, I have seen vaccine hesitancy most prominently from people who are not taking this pandemic seriously. Actually, that’s not even the right way to put it. Most people agree that the pandemic is real and tragic. They just don’t think they will be personally affected by it. I can’t entirely blame Joe Rogan because this sentiment existed before he fanned the flames, but by stating something that people already felt, he legitimized it.

The biggest concern right now is that this type of vaccine hesitancy will only grow with the authorization of vaccines for children and adolescents. Young parents in that 25 percent “wait and see” group will undoubtedly make the same decision for their kids. Other parents who have gotten the vaccine themselves may still question its benefit in kids who are less likely to develop severe COVID-19.

One reason young adults may think that COVID won’t affect them is that a very small proportion (less than one percent) of deaths due to COVID-19 have occurred in people under the age of 30. What this data fail to convey however, is that death is not the only outcome of COVID-19. Clearly COVID-19 is more dangerous to the elderly and people with underlying conditions including diabetes, obesity, and lung disease, but that does not mean it is an entirely safe infection for everyone else. Even mild acute COVID-19 that feels like the common cold can result in serious and longterm effects in children and young adults.

Children with COVID-19 are susceptible to a life threatening (albeit rare) inflammatory reaction called multi-system inflammatory syndrome in children (MIS-C). Additionally, it appears that persisting symptoms of long COVID experienced by many adults is also occurring in children. In a recent study, more than half of children had at least one persisting symptom more than two months after their acute illness. In another study including perhaps the most healthy cohort of patients you could find — college athletes — 40 percent of them were found to have inflammation around their heart after a bout of asymptomatic or mild COVID-19. While the longterm safety of mRNA vaccines has been questioned with no evidence to support it, a growing body of research is revealing longterm effects of COVID-19 even among young healthy people with mild acute illness.

Furthermore, data is accumulating indicating that immunity induced by the vaccines is better than that of actual infection. Imagine getting COVID-19 with long-lasting fatigue or brain fog only to be susceptible to getting it again. This is one of the reasons that vaccination is recommended for people who have already had COVID-19.

In young adults, the risk of blood clots (particularly among women) after the Johnson & Johnson vaccine has also gotten a lot of attention. Rightfully so, when the regulatory agencies paused vaccination in order to investigate. But the unintended consequence was sowing hesitancy without a clear explanation when the vaccine was reinstated. The risk of blood clots after the J&J vaccine is about 1 in 1 million doses of vaccine and about 1 in 250,000 doses among women 18-49 years old. That’s not nothing, but the risk of blood clots due to COVID is at least five times higher, so the benefits of the J&J vaccine still outweigh the risks.

It is also intriguing to me that this blood clot story got so much negative attention and yet millions of women ingest something daily that is associated with a greater risk of blood clots than the J&J vaccine: hormonal birth control pills. Speaking of birth control, there is also no physiologic reason nor evidence to suggest that any COVID vaccine affects fertility. Anecdotally, there have been reports of irregular menstrual cycles after vaccination, though how widespread this is remains unclear. Notably, some people in the vaccine trials and many more in the general population have become pregnant after vaccination.

How does vaccine hesitancy affect the vaccinated? 

One might argue that the unvaccinated shouldn’t matter to the vaccinated, but this argument is a logical fallacy. No vaccine is 100 percent effective, so sustained spread of this virus will continue to expose the vulnerable, even if they have been vaccinated. Continued spread also risks the development of new variants, which could be more transmissible, more severe, or circumvent immunity.

While COVID cases are on the decline overall, there are now more cases, hospitalizations, and deaths among younger folks. This shift in age is mostly attributable to the age-driven eligibility of vaccines in the U.S. (older populations being more immune) and also shows us who is susceptible to disease and who contributes most to spread.

This brings us back to this group of healthy young adults in the “wait and see” group. If their reason to hold off is truly because they don’t see the individual risk of COVID-19 for themselves, we have a bigger problem on our hands. People who think they are invincible to this pandemic are the ones out in their communities — in groups, indoors, in restaurants, movie theaters, and bars. They have simultaneously become the most susceptible and the most likely spreaders. 

Experts are now saying that community immunity (herd immunity) will not be attainable in the U.S. It was never going to be reached without kids and adolescents since they make up more than 20 percent of the population. But with dwindling numbers of vaccinated adults, it appears we are going to fall short of this magic threshold. This is not a reason to wave the white flag. If anything, it is the reason we should push harder to vaccinate as many people as possible.

This pandemic will have an end. When there are fewer people for the virus to infect, cases will dwindle and we can call this over. Yes, there will be isolated outbreaks. Eradication was never the finish line. But we can still save lives.

• Healthy vaccinated communities can help keep the virus away from their elderly and vulnerable residents.
• Fully vaccinated schools and colleges can help keep the virus away from students, teachers, and staff with underlying conditions.
• Vaccinated families can help keep the virus away from their loved ones.

The longer we allow this virus to circulate among our population, the greater the risk of developing a variant that can overcome pre-existing immunity (either attained by infection or vaccination) and having to do this all over again — shutting down the economy, restricting travel, imposing lockdowns. To put it frankly, this has been an insane experience that will have ramifications for years to come. Let’s do everything we can to stop it now.

Roll up your sleeve. Get your jab. Do your part.