Which dose of the 9-valent HPV vaccine is more likely to cause fever?
Nov 06, 2025
Source: Cainiu Health
Dr. Zhang Lu
Introduction
The second or third dose is more likely to cause fever, primarily because the body has already developed an initial immune memory to the vaccine components after the first dose. Upon subsequent vaccinations, the immune system responds more vigorously, resulting in a stronger immune response that may be accompanied by mild inflammatory reactions, thus triggering fever. Such fevers are usually low-grade, short-lived, and typically resolve on their own within 1–2 days.
Generally, receiving the 9-valent HPV vaccine does not necessarily cause fever. However, fever is relatively more common after the second or third dose, while the likelihood of fever after the first dose is lower. Individual reactions may vary. If you have concerns, it is recommended to consult a healthcare provider in advance. Detailed explanations are as follows:
Fever is more likely to occur after the second or third dose because the body has already developed initial immune memory from the first dose. Upon subsequent vaccinations, the immune system responds more actively with a stronger immune response, which may be accompanied by mild inflammatory reactions leading to fever. This type of fever is usually low-grade and short-lived, typically resolving on its own within 1–2 days, and represents a normal immune response.
The probability of fever after the first dose is lower because, upon initial exposure to the vaccine components, the immune system requires time to recognize and initiate a response. The resulting immune reaction is generally milder, making fever less likely. Even if fever occurs, body temperature usually remains in the low-grade range without other significant discomfort. Symptoms can typically be relieved with rest and physical cooling measures, and there is generally no need for excessive concern.
After receiving the 9-valent HPV vaccine, remain at the vaccination site for 30 minutes of observation before leaving, ensuring no adverse reactions occur. After returning home, get adequate rest and avoid strenuous exercise or fatigue. If fever develops, use physical cooling methods such as wiping the body with lukewarm water. Seek medical attention promptly if body temperature exceeds 38.5°C or if the fever lasts longer than three days, to determine the underlying cause and receive appropriate treatment.
