Q&A: How to protect vulnerable populations from COVID

After fighting the COVID-19 for three years, China is adjusting its pandemic response measures to minimize the impact on people's normal lives.

Despite of its weakening virulence, the novel coronavirus still poses a threat to the health of vulnerable populations such as the elderly and people with chronic diseases.

Experiences from around the world prove that increasing the vaccination rates among seniors and people with preexisting health conditions is crucial for humanity to win the combat against COVID-19.

But still, many people have some concerns: Is the vaccine still potent enough to protect us from the new variants? Should I take the booster shots?

To address the concerns, a research team led by Zhang Wenhong from the infectious disease department at Huashan Hospital Affiliated to Fudan University answered some of the most asked questions.

Q: How long can the vaccines protect us? Can the vaccines offer protection against the new variant?

A: Studies show the level of antibodies against the novel coronavirus will increase remarkably in the first 28 days after a person receives two doses of vaccines. However, the level of neutralizing antibodies will gradually drop over time, especially after six months.

A booster shot can improve the level of neutralizing antibodies against the virus, especially against the Omicron variant, which has a strong immunity-evading ability.

A research conducted by our team showed that a third shot can significantly boost the immunogenicity against subvariants of Omicron such as BA.1, and BA.4, and BA.2.75.