Experiencing flu-like symptoms after receiving a COVID-19 vaccine is a relatively common occurrence and a sign that your immune system is responding to the vaccine. These side effects, which may include fever, fatigue, headaches, muscle aches, and chills, are similar to those experienced during a mild flu, thus, are often referred to as ‘flu-like symptoms’. They typically appear within a day or two after vaccination and usually last only a few days. This does not indicate that the vaccine has given you COVID-19; rather, it suggests that the body is building protection against the virus. Understanding these reactions can help to manage expectations and mitigate any concerns related to the vaccination process.
Understand the Vaccines and their Side Effects
A vaccine is a substance that helps your body to build immunity or protection against a specific disease, in this case, COVID-19.
Here are some key coronavirus vaccines approved by the World Health Organization (WHO) and their potential side effects:
- Pfizer-BioNTech and Moderna vaccines: These vaccines use mRNA, or messenger RNA, to teach your cells how to make a protein that triggers an immune response. The immune response then helps protect against COVID-19. Common side effects are pain and swelling at the injection site, fever, fatigue, headache, muscle pain, and chills.
- Johnson & Johnson’s Janssen vaccine: This viral vector vaccine uses a harmless version of a different virus to deliver important instructions to our cells to start building protection against COVID-19. Side effects are similar to the mRNA vaccines: pain at the injection site, headache, fatigue, muscle pain, and fever.
- Novavax COVID-19 vaccine: Subunit vaccines include only the parts of a virus that best stimulate your immune system. This type of COVID-19 vaccine contains harmless S proteins. Once your immune system recognizes the S proteins, it creates antibodies and defensive white blood cells. If you later become infected with the COVID-19 virus, the antibodies will fight the virus.
- Sinovac-CoronaVac Vaccine: It’s an inactivated vaccine. It uses a killed version of the coronavirus that cannot cause disease but can still teach the immune system how to fight off the live virus. As for side effects, similar to other vaccines, Sinovac may cause mild and generally short-lived side effects.
These side effects usually go away on their own in a few days and are a sign that your body is building protection against the virus. These vaccines do not contain the live virus that causes COVID-19, so they can’t make you sick with COVID-19.
It’s important to remember that while these vaccines have side effects, the benefits far outweigh the risks. They are highly effective at preventing COVID-19, especially severe illness and death.
Remember to speak with your healthcare provider if you have any specific concerns or if your side effects do not go away after a few days.
Common Flu-Like Symptoms After COVID Vaccine
Receiving a COVID-19 vaccine can sometimes cause mild side effects that may feel like a mild version of the flu. These are common and are typically a sign that your body is building protection against the virus. The symptoms usually last for a short time, often a day or two, and are more common after the second dose. Here are some of the most common flu-like symptoms after a COVID-19 vaccine:
- Fever: It’s common to experience a low-grade fever after getting the vaccine. This is a natural response as your body builds protection.
- Chest pain: Shortness of breath, feelings of having a fast-beating, fluttering, or pounding heart. If you feel these after vaccination, you should seek medical care urgently.
- Fatigue: You might feel tired or have low energy for a day or two after getting the vaccine. This is one of the most common side effects.
- Headache: Some people might experience headaches, from mild to severe headache. Drinking plenty of water and resting can help with this.
- Muscle or Body Aches: You might experience joint pain, muscle aches, or general discomfort. This is because your immune system is responding to the vaccine.
- Chills: Some people might experience chills, another symptom common to the flu and a body’s reaction to the vaccine.
- Nausea: A smaller number of people might feel nauseous or even vomit. This should go away relatively quickly.
Remember that these symptoms usually go away on their own after a few days. If your side effects last longer than a few days or you have more serious symptoms, contact your healthcare provider. Remember that even with these potential side effects, the benefits of getting vaccinated and gaining protection against COVID-19 far outweigh the temporary discomfort.
Possible Long-Term Complications of Vaccines
The vast majority of side effects from COVID-19 vaccines are temporary and mild or moderate in severity. Serious side effects are rare, and when they do occur, they generally happen within a few days to a few weeks of vaccination.
Long-term side effects, which occur several months or more after vaccination, are poorly understood, primarily because COVID-19 vaccines have only been in use since late 2020/early 2021. That said, no specific long-term complications have been established as being directly linked to COVID-19 vaccines.
As part of the vaccine development and approval process, vaccines are tested extensively for safety and efficacy. The COVID-19 vaccines received Emergency Use Authorization (EUA) from the US FDA (and approval from similar health authorities worldwide) based on large-scale trials demonstrating their safety and effectiveness.
It’s important to note that the long-term effects of vaccines are continuously monitored even after they are approved. This includes the COVID-19 vaccines. Systems like the Vaccine Adverse Event Reporting System (VAERS) in the US and the Yellow Card scheme in the UK collect data on side effects experienced by people who have been vaccinated.
That said, the risk of long-term complications from COVID-19 infection itself is much higher and more well-established. COVID-19 can lead to severe, long-lasting, and even life-threatening complications. These include long-term heart, lung, and neurological issues, often called “Long COVID.” The COVID-19 vaccines have dramatically reduced the risk of severe disease, hospitalization, and death.
For the most current and personalized advice, it’s always best to consult a healthcare provider, who will have the most up-to-date information and understand your health history.
Tips for Managing Side Effects on Your Own
Experiencing side effects after getting a COVID-19 vaccine is normal and usually, a sign that your body is building protection against the virus. Here are a few tips for managing the most common side effects at home:
- Rest and hydrate: Rest and drink plenty of fluids to help manage symptoms like fatigue, fever, and headaches. Staying hydrated also helps your body recover faster.
- Over-the-counter medication: If vaccine recipients don’t have any contraindications, they can consider taking over-the-counter pain relievers such as acetaminophen (Tylenol) or ibuprofen (Advil, Motrin) to help with discomfort or fever. However, it’s generally recommended not to take these medications preemptively before receiving the vaccine but only if you develop symptoms afterward.
- Cool compress: If you have pain or discomfort where you got the shot, apply a clean, cool, wet washcloth over the area.
- Use and move your arm: To reduce discomfort in your arm, use it as much as you can and do some gentle movements or exercises. This can increase blood flow and help reduce the soreness.
- Dress lightly: If you develop a fever, dress lightly and stay comfortable. Don’t bundle up and overheat.
Remember that if symptoms persist beyond a few days or you have concerns about any sign, you should contact a healthcare provider. Furthermore, if you experience symptoms that could indicate a severe allergic reaction, such as difficulty breathing, swelling of the face or throat, a fast heartbeat, a severe rash all over your body, or dizziness and weakness, seek medical attention immediately.