The recent cases of individuals who had completed the two-dose vaccination regimen testing positive for Covid-19 are worrisome, as the ensuing negativity could scuttle the goal of having a sufficiently high vaccination rate here.

The Ministry of Health (MOH) has consistently said that vaccination can prevent serious symptoms and complications of a Covid-19 infection. It has also said that some breakthrough infections are to be expected.

But vaccine naysayers may think that since fully vaccinated people can still get infected, it makes no difference whether one is vaccinated or not.

It is known from past research on other vaccines in real world situations spanning 30 years, and even from recent research on the Covid-19 vaccines themselves, that there are underlying factors that contribute to people responding poorly or not at all to vaccines.

Some important and common factors include central obesity, being overweight, smoking, hypertension, chronic stress, chronic poor sleep and even depression.

Perhaps MOH should make explicit these factors which compromise the effectiveness of vaccines in the real world. Doing so has two benefits.

The first is that by knowing there are background factors for vaccinated people getting infected, one will not unfairly conclude that the vaccines are not effective should such cases arise.

For example, not only are obesity and smoking associated with increased risk for many cancers and cardiovascular diseases, but they also disrupt normal functioning of the immune system, making individuals with such risk factors susceptible to infection even after being vaccinated.

Second, MOH could take this opportunity to educate people that personal health management should be holistic.

People should be advised to stay healthy in normal times, as one never knows when a challenge such as Covid-19 will come around.

Lim Teck Koon