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Dhaka Tribune

Covid-19: The global search for vaccines

Once a vaccine is licensed, researchers continue to monitor people who receive it to make sure it is safe and effective

Update : 27 Aug 2023, 03:01 PM

Covid-19 is currently the focus of attention all over the world. The disease, caused by the novel coronavirus or SARS-CoV-2, originated in China’s Wuhan province, rapidly unfolding worldwide. It has so far killed over 820,000 people.

The whole world is watching to see when the cure for this disease will come. The invention of the coronavirus drug or vaccine is not just an attempt to rid mankind of a terrible virus, but also involves a number of issues, including the establishment of superiority where an invention of vaccines by individual nations is concerned.

Just as Western capitalist countries started an arms race with the socialist bloc after World War II, so too by 2020, more than two hundred countries in the world are competing for the production of vaccines.

Russia on August 11 declared itself the first country to approve a coronavirus vaccine.

Dubbing the vaccine “Sputnik V” after the Soviet-era satellite that was the first launched into space, Russian officials said it provided safe, stable immunity and denounced Western attempts to undermine Moscow’s research.

Scientists in the West have raised concerns about the speed of the development of Russian vaccines, suggesting that researchers might have been cutting corners and coming under pressure from the authorities to deliver.

A global race is underway to develop and mass produce an effective vaccine to counter the new, deadly, and highly infectious coronavirus disease. 

Covid-19 vaccine status

According to the World Health Organization, more than 170 vaccines are under development globally and 32 vaccines are in a process of human trials.

Experts estimate that a fast-tracked vaccine development process could speed a successful candidate to the market in approximately 12-18 months – if the process goes smoothly from conception to market availability.

The University of Oxford with AstraZeneca Plc, Moderna Inc and a partnership of Pfizer Inc and BioNTech SE are among the vanguard. China's CanSino Biologics has received authorization for a limited deployment of its shot among the Chinese military. “Sputnik V” has been developed by the Gamaleya Research Institute in Moscow.

Testing process

In the pre-clinical stage of testing, researchers applied the vaccine to animals to see if it triggered an immune response.

In phase 1 of clinical testing, the vaccine is given to a small group of people to determine whether it is safe and to learn more about the immune response it provokes.

In phase 2, the vaccine is given to hundreds of people so scientists can learn more about its safety and correct dosage.

In phase 3, the vaccine is given to thousands of people to confirm its safety – including rare side effects – and effectiveness. 

Regulators in each country review the trial results and decide whether to approve the vaccine or not. During a pandemic, a vaccine may receive emergency use authorization before getting formal approval. 

Once a vaccine is licensed, researchers continue to monitor people who receive it to make sure it is safe and effective.

Another way to accelerate vaccine development is to combine phases. Some coronavirus vaccines are now in Phase 1/2 trials, for example, in which they are tested for the first time on hundreds of people. 

Vaccine platforms

Most of these vaccines target the so-called spike proteins that cover the virus and help it invade human cells. The immune system can develop antibodies that latch on to spike proteins and stop the virus.

A successful vaccine for the SARS-CoV-2 coronavirus will teach people’s immune systems to make antibodies against the virus without causing diseases.

Most vaccines in use today incorporate an inactivated or weakened form of a virus that is not able to cause disease. When immune cells encounter them, they make antibodies.


Also Read- Study: Covid-19 may produce long lasting immunity


A number of experimental coronavirus vaccines do not deliver whole viruses. Instead, they deliver genetic instructions for building a viral protein. The protein can then stimulate the immune system to make antibodies and help mount other defenses against the coronavirus.

To create a coronavirus vaccine, several teams have added the spike protein gene to a virus called an adenovirus. The adenovirus slips into cells and unloads the gene. Because the adenovirus is missing one of its own genes, it cannot replicate and is therefore safe.

Some vaccines are particles that contain pieces of viral proteins. They cannot cause disease because they are not actual viruses, but they can still show the immune system what coronavirus proteins look like.

Typically take up to six years

According to researchers from Massachusetts General Hospital, a key challenge in developing vaccines for emerging infectious diseases is that each pathogen uses a different mechanism to infect cells and elicits a different immune response from the body. 

The majority of vaccines are built from the ground up to address these unique factors and need to undergo rigorous efficacy and safety testing—a process that can typically take up to six years. 

The majority of vaccines currently being tested and developed rely on previous research, addressing other types of infectious diseases.

For all the uncertainties that remain ahead for a Covid-19 vaccine, several experts were willing to make one prediction. 

“I think the question that is easy to answer is, ‘Is this virus going to go away?’ And the answer to that is, ‘No,’” Ruth Karron, director of the Center for Immunization Research at Johns Hopkins University, told The Atlantic. 

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