How many doses of the COVID-19 vaccine are required?

Many people assume that COVID-19 vaccines, like other vaccines, confer lifelong protection. However, this is not the case—vaccines have a limited period of effectiveness. So, how many doses of the COVID-19 vaccine are required? Below, we address this question.

How Many Doses of the COVID-19 Vaccine Are Required?

Generally speaking, there are three types of COVID-19 vaccines currently available. Inactivated vaccines require two doses, with an interval of 3–8 weeks between them. Recombinant subunit vaccines require three doses; the recommended interval between consecutive doses is four weeks. The second dose should ideally be administered within eight weeks of the first, and the third dose within six months of the first. Adenovirus-vector vaccines require only a single dose. Note, however, that the COVID-19 vaccine is not suitable for certain groups, including pregnant or lactating women, and individuals experiencing acute illness such as fever or active infection. The most common adverse reactions following administration of inactivated COVID-19 vaccines include fever and headache; at the injection site, redness, induration (hardening), and cough may occur. If symptoms persist or worsen and do not resolve spontaneously, prompt medical evaluation is advised.

Knowledge Extension: Post-Vaccination Precautions

1. Observation

After vaccination, you must remain at the vaccination site for 30 minutes for observation to ensure no immediate adverse reaction occurs before leaving. This allows for timely intervention should any unexpected reaction arise. Additionally, monitor yourself closely afterward for signs such as fever or swelling or induration at the injection site. Seek medical attention promptly if any abnormalities develop.

2. Rest

Adequate rest is essential after vaccination; strenuous physical activity should be avoided. Maintain cleanliness and hygiene of the injection site, change clothes regularly, and refrain from scratching the area to prevent local infection or worsening of reactions. If persistent purulent discharge develops at the injection site, consult a healthcare provider immediately.

3. Diet

Maintain a light, bland diet after vaccination. Avoid strongly stimulating foods such as scallions, ginger, garlic, and chili peppers. Furthermore, avoid consuming hot food or beverages—including hot milk, hot water, or hot meals—for at least 30 minutes before and after vaccination. Breastfeeding should also be temporarily withheld during this period, as heat exposure or feeding may potentially interfere with vaccine immunogenicity.

The above outlines the recommended number of doses for COVID-19 vaccines. We hope this information is helpful to you.