Winning the Battle against Covid-19

On need for safe and effective vaccine

The Covid-19 outbreak has fuelled an international demand in the biomedical field for the mitigation of the fast-spreading illness, all through the urgent deployment of safe, effective and rational therapeutic strategies along with epidemiological control. As World Health Organization (WHO) and its partners work together on the response – tracking the pandemic, advising on critical interventions, distributing vital medical supplies to those in need – they are racing to develop and deploy safe and effective vaccines.
Data conclusively say that vaccines save millions of lives each year. These work by training and preparing the body’s natural defences – the immune system – to recognize and fight off the viruses and bacteria they target. Post-vaccination, if the body is exposed to those disease-causing germs, it is immediately ready to destroy them, preventing illness. As of 18 February 2021, at least seven different vaccines across three platforms have been rolled out in countries. At the same time, more than 200 additional vaccine candidates are in development, of which more than 60 are in clinical development.
How Covid-19 Vaccines Work
To understand how Covid-19 vaccines work, it is important to first look at how our bodies fight illness.
When germs, such as the virus that causes Covid-19, invade our bodies, they attack and multiply. This invasion, called an infection, is what causes illness. Our immune system uses several tools to fight infection. Blood contains red cells, which carry oxygen to tissues and organs, and white or immune cells, which fight infection. Different types of white blood cells fight infection in different ways:
Macrophages are white blood cells that swallow up and digest germs and dead or dying cells. The macrophages leave behind parts of the invading germs, called “antigens”. The body identifies antigens as dangerous and stimulates antibodies to attack them.
B-lymphocytes are defensive white blood cells. They produce antibodies that attack the pieces of the virus left behind by the macrophages.
T-lymphocytes are another type of defensive white blood cell. They attack cells in the body that have already been infected.
The first time a person is infected with the virus that causes Covid-19, it can take several days or weeks for his/her body to make and use all the germ-fighting tools needed to get over the infection. After the infection, the person’s immune system remembers what it learned about how to protect the body against that disease. The body keeps a few T-lymphocytes, called “memory cells”, that go into action quickly if the body encounters the same virus again. When the familiar antigens are detected, B-lymphocytes produce antibodies to attack them. Experts are still learning how long these memory cells protect a person against the virus that causes Covid-19.
Different types of vaccines work in different ways to offer protection. But with all types of vaccines, the body is left with a supply of “memory”. T-lymphocytes as well as B-lymphocytes will remember how to fight that virus in the future. It typically takes a few weeks after vaccination for the body to produce T-lymphocytes and B-lymphocytes. Therefore, it is possible that a person could be infected with the virus that causes Covid-19 just before or just after vaccination and then gets sick because the vaccine did not have enough time to provide protection. Sometimes after vaccination, the process of building immunity can cause symptoms, such as fever. These symptoms are normal and are signs that the body is building immunity.
Types of vaccines and their effects
Below is a description of how each type of vaccine prompts our bodies to recognize and protect us from the virus that causes Covid-19. None of these vaccines can give you Covid-19.
1. mRNA vaccines
These contain material from the virus that causes Covid-19 which gives our cells instructions for how to make a harmless protein that is unique to the virus. After our cells make copies of the protein, they destroy the genetic material from the vaccine. Our bodies recognize that the protein should not be there and build T-lymphocytes and B-lymphocytes that will remember how to fight the virus that causes Covid-19, if we are infected in the future.
2. Protein subunit vaccines
Include harmless pieces (proteins) of the virus that causes Covid-19 instead of the entire germ. Once vaccinated, our bodies recognize that the protein should not be there and build T-lymphocytes and antibodies that will remember how to fight the virus that causes Covid-19 if we are infected in the future.
3. Vector vaccines
They contain a modified version of a different virus than the one that causes Covid-19. Inside the shell of the modified virus, there is material from the virus that causes Covid-19. This is called a “viral vector.” Once the viral vector is inside our cells, the genetic material gives cells instructions to make a protein that is unique to the virus that causes Covid-19. Using these instructions, our cells make copies of the protein. This prompts our bodies to build T-lymphocytes and B-lymphocytes that will remember how to fight that virus if we are infected in the future.
To be fully vaccinated, you will need two shots of some Covid-19 vaccines.
Two shots: If you get a Covid-19 vaccine that requires two shots, you are considered fully vaccinated two weeks after your second shot.
Pfizer- BioNTech and Moderna Covid-19 vaccines require two shots.
One-Shot: If you get a Covid-19 vaccine that requires one shot, you are considered fully vaccinated two weeks after your shot. Johnson & Johnson’s Janssen Covid-19 vaccine only requires one shot.
Stopping a pandemic requires using all the tools available. Vaccines work with your immune system so your body will be ready to fight the virus if you are exposed. After you are fully vaccinated against Covid-19, you may be able to start doing somethings that you had stopped doing because of the pandemic. But we’re still learning how vaccines will affect the spread of Covid-19.
Debate in Pakistan
The local production of China’s single-dose CanSino Covid-19 vaccine has started in Pakistan to facilitate the country’s vaccination drive. The local production of the CanSino vaccine will gradually make Pakistan largely self-sufficient in meeting its Covid-19 vaccine needs. Pakistan has a population of 220 million and over 2.5 million people have already been vaccinated owing to the proactive strategy of the government for vaccine procurement.
The primary responsibility lies with Pakistani media to play a sensible and professional role during the ongoing health crisis. The media should avoid any exaggerated or amplified statements triggering negative perceptions related to Covid-19 among the general community. Television channels in Pakistan should avoid airing unsupported conspiracy theories about Covid-19. The most reasonable and ethical approach would be limiting discussions on Covid-19 to healthcare professionals, rather than political or business figures. Although free speech is a fundamental right of every citizen, public harm associated with false claims must be carefully weighed. Another approach could be useful debates that offer opinions from researchers or healthcare professionals to counter conspiracy theories.
Keeping in view the large circulating volume of mis- or dis-information, researchers and public health educators need to build a society that is resilient to falsehood about Covid-19, a task that will only become more vital as vaccines near. Data scientists and communications researchers have the responsibility to analyze data related to such misleading information. It is not possible to stop people from spreading ill-founded rumours. However, analysis of information sources, patterns of spread and impacts on the general community will foster effective strategies so that misleading information cannot spread as far and as fast. In the case of vaccines, transparent information on how vaccines are made, how they work, what they contain, how they will be tested, and their effectiveness, possible risks, and side effects will use to ensure confidence in Covid-19 vaccines when they are available. The government of Pakistan has not taken a hard line against misleading Covid-19 claims. I believe that putting full effort into the implementation of the aforementioned measures will go a long way in mitigating the proliferation of false claims in the country, and thereby help greatly in the control of the Covid-19 pandemic in Pakistan.

The writer is a PhD Scholar (English Literature).
He can be reached at: hbz77@yahoo.com