During Roya’s news bulletin Saturday, Microbiology specialist Suhaila Al-Shboul recommended the Kingdom temporarily halt its efforts to obtain the Pfizer and Moderna vaccines, saying the side effects are not yet known.

She described that vaccines are usually developed in four different ways: using the whole virus, protein subunits, through viral vectors, or nucleic acid (RNA or DNA)

When using the whole virus, a vaccine is made by using a weakened or inactive virus which can still be replicated without causing sickness but can cause an immune response.

The Chinese Sinovac and Sinopharm are whole-virus vaccines.

Making a vaccine with protein subunits uses pathogens, such as protein fragments, to trigger a response from the human immune system. This minimizes the risk of side effects, but may result in a weaker immune response.

Viral vector vaccines send ‘instructions’ to cells in order to produce antigens. However, they differ from Nucleic acid vaccines by using a ‘harmless’ virus which is different from the virus which the vaccine targets, in order to deliver the instructions. These vaccines may mimic natural viral infections which will trigger strong immune responses.

AstraZeneca utilizes the viral vector vaccine method.

A nucleic acid vaccine uses genetic RNA or DNA material to assist cells with creating antigens. In COVID-19, the spike protein which is responsible for making an individual ill will be used to enter cell protein factories to make antigens which will trigger the immune response.

However, DNA and RNA vaccines, created by Pfizer and Moderna, have never been licensed for use until now, noted Al-Shboul.

The technology used to develop these two vaccines was also not tested on humans, but on animals, and they were developed in a laboratory setting, she added.

She expressed her reservations towards the RNA vaccines, saying "We need time to find out what is going to happen," noting that this is the first time that these kinds of vaccines have been tested on humans.

Shboul indicated that although side effects were evident during phase III of RNA vaccine trials, it cannot possibly indicate how the body will react to the vaccine because genetically modified viruses were used in the making of the vaccine, therefore it prevents specialists from knowing the real reasons of why the symptoms occurred.

These messenger RNA's have been modified in laboratories and have been stabilized, said Shboul.

Therefore when these proteins enter cells, who knows how long they will remain there, she questioned.

It could remain in cells for "one month, two months, six months, maybe a year, we do not know," said Shboul.

On a molecular level, she said that microbiology stipulates that many things may occur within human cells, and this modified gene may cause a variety of unknown genetic changes in the body.

"We need more time," said Shboul of the Pfizer and Moderna vaccines.