Why are those getting the COVID-19 vaccinations experiencing headaches, fevers or chills the next day? Medical professionals stress that such reactions mean the vaccine is doing its job — teaching your body how to fend off the coronavirus.
As vaccines for the coronavirus are gradually made available to more and more members of the public, researchers and medical professionals want people to prepare for what it means to be vaccinated and what to expect when getting the key second dose.
Understanding those details will be crucial to finally turning the page on the COVID-19 pandemic, when we can transition back to a relatively normal state of affairs. For that to happen, the large majority of the population will likely need to be inoculated.
“The only way we’re going to get out of the situation with COVID-19 is an aggressive vaccine campaign, but I think because of the speed with which the vaccine was developed and also some political turmoil, there are some doubts about the efficacy of the vaccine,” explained Dr. Nicholas Testa, the divisional chief medical officer of Dignity Health’s Southern California Division. “To get to this idea of herd immunity, the number that they’re looking at is having somewhere between 70 and 90% of the population being vaccinated.”
The vaccines produced by Pfizer and Moderna, both of which were approved for use in the United States in December, were developed using mRNA vaccine technology. Testa said that this type of vaccine is relatively easy to develop because the framework is always the same — what pharmaceutical developers need to do is insert a harmless part of the disease, called a spike protein.
“All they need is that gene sequence for the spike proteins and they just insert it in there and it’s ready to go. It took about a week to develop,” he said. “Clinical trials, if I’m not mistaken, started in June or July, so in just a few months, we were able to get to a point where we were able to start those trials.”
This is different from the typical live-attenuated vaccines, which actually involve using a piece of the disease to provoke an immune response. Research into mRNA vaccines began in the 1990s and their first use in clinical trials was in 2014.
“It doesn’t go into your nucleus. It doesn’t touch your DNA,” Testa said. “If you get infected with the virus, it hijacks the whole operations of the cell to produce more virus and eventually destroy the cell.
“There’s a perception that mRNA technology is new and has never been tested before,” he added. “If we were going to see the long-term effects that people fear, we’d have seen them by now. This is not brand new technology that just appeared yesterday or was just created for this vaccine.”
So what’s with all these stories about people getting their second doses and feeling as if they might have gotten the flu the next day?
That is “your immune system going to work,” said Mary Virgallito, associate administrator for quality and patient safety at USC Verdugo Hills Hospital. “The vaccine is basically showing the body what it needs to do to fight against the virus.”
With the two-dose vaccines, patients’ bodies use the first shot to basically break down the genetic code of the virus and develop an immune response based on that. The second shot essentially tells the body to let ‘er rip.
“It means your body’s making antibodies,” said Dr. Harry Balian, chair of the cardiology department at Adventist Health Glendale. “It’s preparing you for the real deal.”
Balian said he had a fever and chills after his second dose but was quickly back to normal. For those experiencing side effects, that is almost always the case.
“You might feel tired or achy,” said Virgallito, who handles infection prevention and control management at USC-VHH. “You might have a fever, and you’ll probably have a sore arm afterward. That’s the indication that the vaccine is doing its job. You’ll probably get the experience where you’re achy and have chills and feel lousy, but it’s going to be that way for a day.”
Even when you are vaccinated, it will still be important to continue following public health guidelines such as social distancing, wearing face masks and taking extra care to sanitize surfaces. As has been well documented, the vaccines being used now are around 80%-90% effective in preventing COVID-19.
However, medical officials stress, that is not the number to pay attention to when assessing new vaccines. A new single-dose shot developed by Johnson & Johnson is generating excitement because of the company’s production capabilities and also, importantly, because it does not need to be refrigerated.
So, what about that part of it being 66% effective in preventing COVID-19? Like the Pfizer and Moderna variants, this one also was 100% effective at preventing serious illness from the disease and preventing the need for hospitalization.
“Look at their efficacy of preventing hospitalization or death,” Virgallito stressed. “That’s what you need to look at. That’s the goal of any vaccination program. We don’t vaccinate against the common cold because that won’t put you in the hospital. If an adult gets chicken pox, which many of us have as kids, they can get hospitalized and may die.”
Put simply, yes it is possible to still pick up COVID-19 even after being vaccinated, but it will have no worse an effect on you than having the flu.
“They’re not going to have that organ system failure that is just catastrophic,” Balian said. “You may still get it, but you’re not going to hit that peak COVID storm and end up in the ICU and ventilator. Once you’re intubated with COVID storm, your mortality is upwards of 70-80%. That’s a huge number. It’s a very grim picture.”
Added Virgallito: “Most people think, ‘Oh I just get vaccinated so I won’t get sick.’ And yeah, that’s a side benefit. But look at the flu vaccine: I’ve had the flu vaccine every year for 23 years and I’ve gotten the flu a few times, but I’ve never been hospitalized. I’ve always rebounded and so while I have gotten sick, I’ve never experienced a bad outcome, which is the point of the vaccination.”
Reopening society more and more will depend on what data shows with regard to the continuing spread of the coronavirus, in addition to simply how quickly people can get vaccinated. The Biden Administration recently announced a deal with Pfizer and Moderna for 200 million more doses by this summer, and this week Johnson & Johnson asked for emergency approval of its vaccine.
“I’m still masking. I’m still social distancing. I’m still following all the public safety measures because those are key measures. My kids aren’t vaccinated, so I need to make sure I’m doing all those key things to keep people safe,” Virgallito said. “We need to know if vaccinated persons can spread, so that’s going to be key. We need to understand how that works. We’re hopeful that it’s going to be the case, as with other vaccines, but it’s still too early to tell.”
In preparing to receive their second doses, people should ensure that someone is at least available to care for them if the side effects become severe. Eating well and getting enough rest ahead of time will help your body be best prepared to weather the immune response. Headaches, arm soreness and joint pain are most common, while more intense fevers and chills, nausea and dizziness have been reported as occurring.
Although over-the-counter pain relievers such as acetaminophen do help relieve fevers and the inflammation that causes soreness, there is some thought in the medical field that this could actually inhibit the necessary immune response in this case.
“If you’re medically desensitizing your body’s immune response, you may be actually taking away the efficacy of the vaccine,” Balian said.
Some of the data also indicates that older patients are less likely to have the sort of response that will leave a younger person couch-bound and wrapped in blankets for a day.
“Interestingly enough, people over 55 tended to have fewer side effects than younger people did, at least in the Pfizer study,” Virgallito said. “It’s always good to have someone to support you on hand, but at the very least, know who you’re going to call.”
At the end of the day, people should be careful to seek advice from authoritative sources and to allow skepticism for anecdotes that don’t paint a large picture. For every story about an adverse reaction to a vaccine, there are countless others who had some side effects and were otherwise fine.
“I believe that everybody should read and educate themselves, but I really encourage people to validate the sources they go to,” Testa said. “I really encourage people to look at the academic institutions that they believe in. Don’t just read the sensational bits of news that come out through Twitter or Instagram — or frankly, some of the news media. There’s a lot of emotion for the people who are getting the vaccine. People are being very thoughtful, but also being very cautious. I don’t want people to be chasing down and reading anecdotal pieces of information that will have a negative effect on their health.”
