COVID Vaccine Safety and VAERS: 4 Common Questions Answered

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Several superficially plausible arguments against COVID-19 vaccination continue to pop up across the internet, usually phrased as leading questions. Are they as solid as they seem? A little investigation suggests they are mostly speculation.

Vaccine skepticism comes in many different varieties. Much of it centers around strange claims that are outright ridiculous: vaccines are mind-control tools; they're as dangerous as chemical weapons; they're being used to cut the global population. There are many similar examples floating around the internet. But not all arguments used in opposition to vaccination are so easily refuted. In fact, some of them sound superficially plausible, and they must be convincing to many because I see them repeated in our comments sections almost daily.

With that in mind, I want to examine four questions that commonly come up in response to our articles about the COVID-19 shots. This relatively short piece won't settle the debate, though hopefully it will give some context to these otherwise alarming rhetorical questions.

  • Why are so many vaccine adverse events never reported?

Vaccine skeptics frequently visit our comments sections to inform us that many people never report their adverse reactions to the vaccines, the implication being that the shots are injuring or killing lots people and we just never hear about it. It's true that many adverse events go unreported, as surveillance studies regularly acknowledge, but this is not evidence that the vaccines are deadly.

The most reasonable explanation is that the majority of adverse reactions are relatively minor and thus never reported to VAERS. As a fail-safe, however, the FDA monitors active surveillance systems that contain large-scale claims data and electronic health records “to detect additional safety signals that may not have been reported as adverse events to passive surveillance systems.” [1]

The alternative explanation is that thousands of people have been injured by the vaccines and they, their physicians and their insurance companies have simply refused to report the reactions. That probably happens in some cases, but we have mechanisms in place to minimize that outcome.

  • Why have there been more adverse events than ever before?

The COVID vaccines have generated more VAERS reports than any (or all) other approved shots, the argument goes. Yet the medical establishment dismisses this record level of reporting as a coincidence, unrelated to the immunization campaign. This concern also has a less sexy answer, I think, for two reasons.

It's well known that the introduction of new shots and intense media coverage of vaccination stimulate VAERS reporting. This isn't a post-COVID-19 rationalization either; reports of adverse events increased following the introduction of the HPV vaccine in 2006 and the H1N1 flu shot in 2009, to cite two examples.

Additionally, more than seven billion COVID vaccine doses have been administered around the world. Most other vaccines, in contrast, are administered to select age groups or at-risk demographics. The HPV vaccine, for example, is usually only given to boys and girls in their preteen and teenage years. But even when we consider seasonal flu vaccination, which is recommended for everyone six months and older, coverage isn't anywhere near that of the COVID shots. According to a July 2019 review:

[O]ur study shows a remarkable decline in the global distribution of seasonal influenza vaccine doses from 1.5 billion in 2013 to 276.4 million doses by 2017. The global production capacity of seasonal influenza vaccine peaked in 2013, the highest since the launch of the Global Action Plan (GAP) for influenza vaccines in 2006. 

It's not surprising that the COVID-19 shots have substantially boosted adverse event reporting given their widespread use and the intense media coverage they've generated. If you're not impressed by these vaccine comparisons, researchers also conduct follow-up surveillance studies based on VAERS data, which (as I've already mentioned) so far show that the shots are safe for most people.

  • Why should I trust surveillance studies?

I understand why many people ask this. With everybody spinning the data to suit their preferred pandemic narrative, it's easy to view these vaccine safety studies as efforts to defend the shots rather than uncover their potentially harmful side effects. But I think this uber-skeptical analysis is wrong for several reasons.

For one thing, many of the studies just compare the rates of adverse events following vaccination to background rates of the same outcomes, or they compare outcomes in people who receive different vaccines. There's nothing dubious or secretive about the methodology of these studies, and most of them can be read for free online. The more important point is that skeptics often argue in a circle; they cite VAERS reports in response to studies that show those reports to be inconsequential.

On a related note, no one is trying to bury evidence showing that vaccines can injure people. It is quite easy to find peer-reviewed articles that propose a mechanism by which the mRNA shots, say, could cause thrombocytopenia (low blood platelet count). The possible side effects of the COVID-19 vaccines are being very carefully investigated.

  • Why did Pfizer and Moderna vaccinate their control groups?

It's been widely reported that both Pfizer and Moderna immunized the controls in their vaccine clinical trials once the FDA authorized their shots. Skeptics complained that this decision made it more difficult to assess the long-term safety of the vaccines. While that's true, it would have been unethical to withhold the vaccines from controls who wanted them once the necessary safety and efficacy data were generated. Vaccine expert Dr. Ben Locwin outlined the inherent tension in the decision in an email to ACSH:

It's a tug-of-war between the two positions: The public health service of protection during a pandemic versus the value of long-term scientific knowledge. The latter is often worth much more. There have been drugs (hormone replacement (HRT) for women post-menopause, e.g.) whose long-term negative consequences were not seen for many years, and only the real data could overturn the dogma of what was thought to be true, which in hindsight wasn't. 

Those choices are best made in isolation from health and economic variables; it's much more difficult amid a public health emergency. Certainly the science would benefit more from pristine control groups that are untreated. But we also must acknowledge the principles within the Declaration of Helsinki and its protections of human subjects, lest we regress in our approach to humane trials.

Nonetheless, the vaccine manufacturers are still conducting follow-up studies to monitor the long-term outcomes of individuals post-immunization. Indeed, they are required to do so by law, Locwin added. Those studies could certainly reveal previously undetected complications caused by the vaccines; they could also just confirm what the existing evidence shows—that the shots do much more good than harm. 


The takeaway for now is that these four questions are intended to generate only one answer. Why are adverse events under-reported? The vaccines are dangerous. Why are there so many adverse events? The vaccines are dangerous. Why vaccinate the controls? To hide that the vaccines are dan—you get the point.

Any risks the vaccines may carry should be made known to the public so we can make informed decisions. But we should also consider the possibility that those risks are rare and manageable. Many of us are not open to that conclusion. 


[1] Active surveillance is performed with the Sentinel BEST (Biologics Effectiveness and Safety) System and the CMS system. Read more about them here.