Booster shots deemed necessary to fence against another upsurge

Earlier this year, Pakistanis were led to believe that the dark cloud of the global coronavirus pandemic has finally passed the region, heralding a new dawn for resumption of life and normalcy. However, the few months of peace that the country experienced may have only been the calm before the storm, as cases once again seem to be climbing in the port city, crossing an overall positivity ratio of over 22 per cent amid the latest viral surge.

Medical experts fear that this is the doing of a new variant of Omicron, called BA.5, which had been lurking in the shadows undetected for some time, and has now broken into the open. While much of the disease is still centered in Karachi and Hyderabad, it is believed that a great majority of Pakistan’s population may find itself defenceless against BA.5, if the virus spreads to other cities.

The reason for this, explains Dow University of Health Sciences (DUHS) Department of Pathology Head Professor Dr Saeed Khan, is that coronavirus antibodies only last between four to six months in the system after immunisation, before gradually fading out.

“Considering that most people got their anti-coronavirus shots and boosters sometime last year, it’s quite probable that they may have lost their antibodies for the virus by now, making them susceptible to BA.5,” he opined, stressing that it is essential that anyone who may have received their last anti-coronavirus shot anywhere between five to six months ago, immediately get inoculated by a booster jab.

The doctor also maintained that after forsaking SOPs for almost half-a-year, it is time to once again mask up and start social distancing. While the virus is still most prevalent in the port city, the doctor fears that there is a high probability that it will escape to other cities as well.

“The number of people affected by the new variant used to be only one per cent but now it has reached two per cent, and we will be in a crisis situation if it grows further,” he warned.

History of anti-coronavirus jabs

It should be noted that the year 2020 was when Pakistan battled the worst of Covid-19, with little information and no defence mechanisms in place. A year later, the vaccines were introduced worldwide and reached Pakistan in the summer of 2021. For most commonly available vaccines, the prescribed dose was two injections, which at the time may have seemed sufficient.

However, as people continued to be affected by the virus despite completing their anti-virus dose, it was soon realised that antibodies only last in the body for a few months, after which boosters are required to revive immunity. Since then, the government, on the advice of medical experts, has been urging people to get a booster shot six months after their last jab.

How boosters work

Explaining the process of how antibodies and booster shots work, Dr Obaid Ali, who is a specialist in medicine, said that vaccines are engineered to make antibodies against viruses.

Whenever the body produces antibodies against a certain virus, they have a limited time frame of activity, following which the body’s natural processes wash them out.

“However, even though the protein produced as a result of the vaccine may expire after a while, this does not mean that the memory of making the said protein in the body also expires.

When a similar virus invades the body again, the memory that the body retains enables it to automatically start producing the required protein. So, in theory, vaccines last a lifetime. There is no precedent for re-vaccination.

However, it is the antibodies that have a lifespan and booster shots are designed to trigger the body into creating the said antibodies, so when the virus attacks, there is plenty of antibodies available to fend off any viral infection,” he told The Express Tribune.