Is It Normal to Have a Slight Fever After AZ Vaccine?

Q: Is It Normal to Have a Slight Fever After AZ Vaccine?

Dear Ms. Yu： 1. The AstraZeneca COVID-19 vaccine is a non-replicating viral vector vaccine that contains the gene for the SARS-CoV-2 spike protein (S protein) delivered via an adenovirus vector. 2. Possible reactions after vaccination primarily include pain and

After receiving the AZ vaccine, the body temperature may be elevated?

Hello, doctor.
I would like to ask, I received the AstraZeneca vaccine a week ago, and my current body temperature fluctuates between 37.2 and 37.8 degrees Celsius (my usual temperature is between 35.8 and 36.5 degrees).
I feel fatigued but have no other symptoms, and I have no history of exposure or travel.
I have hardly gone out recently, and I live in the southern part of the country.
Do I need to seek medical attention? Thank you, doctor.

Yu, 20~29 year old female. Ask Date: 2021/06/05

Dr. Xiao Yongxun reply Family Medicine

Dear Ms.
Yu:
1.
The AstraZeneca COVID-19 vaccine is a non-replicating viral vector vaccine that contains the gene for the SARS-CoV-2 spike protein (S protein) delivered via an adenovirus vector.
2.
Possible reactions after vaccination primarily include pain and swelling at the injection site, which typically resolve within a few days.
You may apply a cold compress, but please refrain from rubbing or scratching the injection site to avoid potential cellulitis.
Fever (≥38°C) may occur after vaccination, usually subsiding within approximately 48 hours.
Other possible reactions include fatigue, headache, muscle pain, elevated body temperature, chills, joint pain, and nausea.
These symptoms tend to decrease with increasing age and are generally mild, resolving within a few days.
If you experience severe persistent headache, changes in vision or seizures, severe and persistent abdominal pain lasting more than 24 hours, severe chest pain or difficulty breathing, swelling or pain in the lower limbs, or spontaneous skin bleeding, bruising, or petechiae, you should seek immediate medical attention and inform the treating physician of your vaccination history with the AstraZeneca vaccine within the past 28 days.
3.
Your condition appears to be within an acceptable range.
It is recommended that you drink plenty of warm water to help with heat dissipation, consume an adequate amount of fruits and vegetables daily, and ensure sufficient sleep.
If there is no improvement in two to three days, please discuss your situation with your family physician before making any further decisions.

Reply Date: 2021/06/05

More Info

After receiving the AstraZeneca (AZ) vaccine, it is not uncommon for individuals to experience a slight fever as a side effect. The immune response triggered by the vaccine can lead to various symptoms, including fever, fatigue, headache, muscle pain, and chills. These symptoms typically arise as the body builds immunity against the virus and are generally mild and self-limiting.

In your case, having a body temperature ranging from 37.2°C to 37.8°C (approximately 99°F to 100°F) one week after vaccination is within the expected range of post-vaccination reactions. Most individuals experience a peak in symptoms within the first few days following vaccination, and these symptoms usually resolve within a week. The slight fever you are experiencing is likely a normal response as your body is developing an immune response to the vaccine.

It is important to note that while mild fever and fatigue are common, you should monitor your symptoms closely. If your fever persists beyond a few days, exceeds 38°C (100.4°F), or if you develop additional concerning symptoms such as severe headache, difficulty breathing, chest pain, or any other unusual symptoms, it would be prudent to seek medical attention.
Additionally, you mentioned that you have not had any recent exposure to COVID-19 and have not traveled, which further suggests that your symptoms are likely related to the vaccine rather than an active infection. However, it is always wise to consult with a healthcare provider if you have any concerns about your health post-vaccination.

In terms of managing your symptoms, staying hydrated and resting can help alleviate feelings of fatigue. Over-the-counter medications such as acetaminophen (Tylenol) can be used to help reduce fever and discomfort if needed. However, it is advisable to use these medications only if your symptoms are bothersome.

In summary, a slight fever after receiving the AZ vaccine is generally considered a normal side effect and should resolve within a week. Continue to monitor your symptoms, and do not hesitate to reach out to your healthcare provider if you have any concerns or if your symptoms worsen. Vaccination remains a crucial tool in controlling the spread of COVID-19 and protecting against severe illness, so it is important to complete your vaccination series as recommended.

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