The safety of the COVID-19 vaccines remains a top concern among those who are unvaccinated. Yet, researchers and medical doctors at Penn State explain that the results of rigorously conducted clinical trials and comprehensive safety monitoring after widespread vaccine uptake among the public suggests there is little to fear, and they strongly encourage those who are on the fence to get vaccinated.
“The clinical trials behind the Food and Drug Administration’s (FDA’s) decision to grant emergency use authorization to the COVID-19 vaccines demonstrate an excellent safety profile and since then, the vaccines have been given to millions and millions of people worldwide with robust safety monitoring,” said Catharine Paules, infectious diseases physician, Penn State Health Milton S. Hershey Medical Center. “I don’t think any drugs have ever been scrutinized to the degree that these vaccines have. I feel very confident in their safety.”
What about side effects?
Before granting emergency use authorizations to Pfizer and Moderna in December 2020 and Johnson & Johnson in February 2021, the FDA monitored side effects in tens of thousands of clinical-trial patients for two months following administration of the vaccines.
“We do see some mild side effects — specifically fatigue, muscle aches, headaches, and less commonly fevers — from the vaccines, but more severe side effects — such as anaphylaxis and myocarditis, and blood clots with the J&J vaccine — are extremely rare,” said Leslie Parent, vice dean for research and graduate studies, Penn State College of Medicine. “Importantly, the risks associated with COVID-19 far outweigh these very, very rare safety concerns.”
Parent added that the likelihood of any additional side effects showing up is unlikely.
“Any side effects from the vaccines would have shown up within a few months of monitoring,” she said, “and long-term health problems have not been reported in millions of people who have been vaccinated.”
Meanwhile, the FDA is continuing to monitor the clinical trial patients who have now been vaccinated for about a year. In addition, the vaccines have been distributed to the public since December 2020.
“If we were going to see any significant long-term concerns related to safety,” said Parent, “we would have seen them by now.”
How can something developed so quickly be safe?
All three vaccines — Pfizer-BioNTech, Moderna and Johnson & Johnson — have been thoroughly tested and found to be safe and effective.
“Absolutely no safety corners were cut,” Paules said. Indeed, she added, “the COVID-19 vaccines were developed faster than any other vaccines in history, but that doesn’t mean they’re unsafe.”
Paules explains that the COVID-19 vaccines were able to be developed quickly because different stages of development and production, which normally occur one after the other, were carried out in tandem, and the scientific community was leveraged in an unprecedented way.
“Each of the stages of development were conducted rigorously, but priority funding, scientific collaboration, rapid data review and clinical trial volunteers made it possible to do these things quickly,” she said.
Isn’t the vaccine technology new? Can I trust it?
Some people have cited the “newness” of the vaccine technology as a concern, but it turns out the technology is not new at all.
“In fact,” said Paules, “mRNA vaccines have been in development for decades. Prior to the COVID-19 pandemic, both Pfizer-BioNTech and Moderna had been working on mRNA vaccines for influenza, and scientists had already conducted clinical trials of an mRNA vaccine for HIV.”
The Johnson & Johnson vaccine uses an adenovirus to deliver the instructions for building the coronavirus’s spike protein. This technology is not new either; the Zabdeno/Mvabea Ebola vaccine uses a similar strategy.
Should I wait for the FDA to fully approve the vaccines?
No. Waiting is a mistake, said Parent.
“People who decide to wait to get vaccinated are putting themselves and those around them at serious risk of COVID-19 and associated complications,” she said. “Now is an especially dangerous time to be unvaccinated given that the highly transmissible and potentially more dangerous Delta variant is now the dominant strain in the U.S. If you haven’t been vaccinated yet, don’t wait any longer. These vaccines have been shown to be safe and effective — the sooner you get vaccinated, the less likely new dangerous variants will arise, and the safer we all will be.”
You can help by getting the vaccine and encouraging everyone ages 12+ to do so, as well. Penn State students, faculty and staff are strongly encouraged to get the COVID-19 vaccine and should upload their vaccination records as soon as possible. With this information, University officials will be able to better assess vaccination rates across Penn State and plan for the fall activities that we all love. The latest vaccination information is available on Penn State’s virus information website.