The sole local case infected with Covid-19 after having completed his vaccination, drives home the fact that vaccination may not protect one from infection by the virus (Worker in dorm who got both jabs is sole new local case, April 12).

Is the public adequately cautioned and aware that vaccination does not necessarily protect one from being infected and from infecting others?

The huge crowds gathering at public places (Buzz returns to Lucky Plaza, Peninsula Plaza, April 12) seem to tell us otherwise.

People may develop a false sense of safety after completing their vaccination.

But while vaccination may reduce the severity of the illness, it may not prevent infection.

We must still be on guard against Covid-19 infections, whether we are vaccinated or not.

In particular, those who plan to travel overseas, especially to places with high Covid-19 infection rates, must realise that their risk of getting Covid-19 is still significant. Taking measures to protect against infection is no less important.

At home, the public should greet the reopening measures not with excessive enthusiasm, but with guarded optimism.

Whether one is vaccinated or not, hygiene practices, wearing of masks and social distancing should not slacken, but be enforced just as strictly as before.

Given the uncertain short- and long-term developments and outcomes of the Covid-19 pandemic, these measures to protect ourselves and others are just as essential and important, if not more so, as vaccination.

The recent Singapore study of immunity to Covid-19 among those who were infected reveals to us that immunity in infected people is highly variable and may last for only 35 days.

So what about those who are vaccinated? How long will their immunity last? How quickly will their immunity wane? Even if repeat vaccination is recommended, what is a safe, practical duration?

While vaccination may be of priority in some situations or countries despite certain flaws, this sole new local case reveals to us one limitation of vaccination.

It emphasises to us that practical safety measures should not be forgotten if we aim to protect ourselves and others around us.

Ho Ting Fei (Dr)