As thousands of people become infected and are killed by COVID-19 daily, scientists and doctors the world over are working hard to come up with its medicines and vaccines. Here is a look at what a vaccine is and a short history of its development
By now, the whole world has become somewhat used to living with the precautions for COVID-19. None of us like it, but we all take care to avoid getting infected with this new disease that is playing havoc in every part of the world.
Never has the saying, “Prevention is better than cure,” been more applicable than it is now, because there is no cure for the coronavirus disease. Yes, there is no medicine that specifically treats this disease, though various medicines are being used to treat the symptoms and issues that arise from it and in most cases they help in recovery. There is also no vaccine that a healthy person can take to safeguard against this virus, as is done in the case of many other diseases.
Scientists and doctors the world over are working very hard to come up with possible cures for COVID-19 and trials for some vaccines are also underway, but it will take some months, if not years, before a tried and tested medicine and vaccine come up. Till then, we have to be very alert, take maximum precautions and avoid going out unnecessarily.
We all have a general idea that a vaccine is something that a person can take to prevent being infected by a certain disease. Let us take a closer look at what a vaccine really is and what it does, and this will help us understand what scientists are doing right now and why it takes time to develop a vaccine.
What are vaccines?
A vaccine is not the cure for any disease, but it helps in making our body develop its own natural ‘army’, or what are called ‘antibodies’, to fight with a disease when its germs enter our body.
According the Vaccine Knowledge Project of University of Oxford, “A vaccine is a type of medicine that trains the body’s immune system so that it can fight a disease it has not come into contact with before. Vaccines are designed to prevent disease, rather than treat a disease once you have caught it.”
Thus vaccines trigger our immune system to develop immunity towards a disease so that our antibodies attack the germs before they can make us sick. Thus vaccines are used as a preventive measure and not as a treatment for any disease as they are designed to be used before a person falls sick due to the disease it is designed for.
Vaccines are made from the same germs, but the germs are either killed or made very weak so that people do not fall sick due to the germs. They are introduced in our bodies through injections. When our immune system finds these germs in our body, it reacts to the vaccine in the same way as it would when encountering the actual germs of the disease.
The antibodies become active, generating more antibodies to destroy the vaccine germs, just as they would attack the germs of the disease. The antibodies once developed stay in our body, giving us immunity against the actual disease. And which is why people who have fallen ill due to diseases such as measles or chickenpox, will not have it again even if they are exposed to its germs again because they have developed immunity to the disease.
This also means that people who are vaccinated will not be passing on the virus to others and this leads to what is known as “herd immunity”.
But this process works only when the germs of a disease stay the same, such as in measles, chickenpox, hepatitis and others. Their vaccines don’t change from year to year because their viruses do not change. However, in the case of other diseases, booster shots or periodic injections of a vaccine are needed to keep up with the changes the germs are undergoing.
Take for instance, the flu vaccine. You need to take these vaccine shots in each flu season, because with time the virus changes, making the previous year’s vaccine partly or totally useless.
Yes, a virus is very smart, when it encounters resistance in terms of immunity in people, it changes itself and attacks again. So scientists also work to update the vaccine to tackle the changes in the new kind of virus.
Update on the COVID-19 vaccine
Developing a vaccine is not an easy job. Vaccines usually take years and even decades to develop, test, approve, manufacture and distribute globally. Already there are many doctors and scientists who are working on developing a vaccine for the Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which is COVID-19’s full scientific name.
According to a report by Reuters, “Around a hundred drug development teams worldwide, including institutions, biotechs and big pharma companies, are racing to develop vaccines against COVID-19 amid a pandemic.”
Coronavirus vaccine trials have been started by some of these teams, on small groups of humans and animals, but scientists urge caution as they have to carefully study the data and conduct more trials before any one of these vaccines can be approved.
In the meantime, all we can do is to boost our immune system by having a healthy diet that contains lots of vitamins, especially vitamin C, and keep on maintaining social distancing to prevent COVID-19’s spread.
Eat well, keep well and keep your distance.
A timeline of some vaccines
The practice of increasing the body’s immunity to combat various diseases is a very old one, going back centuries. The Chinese are believed to have practised smallpox inoculation (the introduction of an antigenic substance or vaccine into the body to produce immunity to a specific disease) as early as 1000 CE. This was also practised in Africa, parts of Asia, before it spread to Europe and the Americas.
The first vaccine — smallpox: In 1796, Edward Jenner inoculated a 13 year-old-boy with vaccinia virus (cowpox), leading to immunity to smallpox and he is thus considered is as the founder of vaccinology in the West.
In 1798, the first smallpox vaccine was developed. In 1979, smallpox was considered globally eradicated thanks to its vaccination.
The polio vaccine
On March 26, 1953, American medical researcher Dr Jonas Salk announced his successful test of a vaccine against poliomyelitis, the virus that causes the crippling disease of polio. By 1955, the vaccine was licensed as an effective and safe vaccine, and a nationwide inoculation campaign began.
Measles, mumps and rubella: In 1963 the measles vaccine was developed, while a vaccine to protect against mumps came up in 1967 and for rubella in 1969. These three vaccines were combined into the MMR vaccine in 1971.
Hepatitis B: Dr Blumberg and Dr Millman developed the first hepatitis B vaccine, which was initially a heat-treated form of the virus, in 1969, which was four years after their discovery of the hepatitis B virus. However, it was only in 1981 that a more sophisticated plasma-derived hepatitis B vaccine for human use.
Hepatitis A: It was in 1947 that hepatitis A was differentiated from hepatitis B. A vaccine for hepatitis A was introduced in 1995.
Influenza: The influenza virus was first discovered in the early 1930s and the flu vaccine was approved for military use in 1945 and civilian use the following year.
This article was originally published in Dawn, Young World, on June 13th, 2020. You can read it here.