An Epidemiologist’s Take on the Risks and Rewards of COVID Vaccines


Vaccinations against COVID-19 began in Armenia on April 13. This first phase of the rollout is for residents and staff at nursing homes, at-risk groups, those over the age of 65, chronically ill people aged 18-64, and staff at social care centers. 24,000 doses of AstraZeneca and 15,000 doses of the Sputnik-V vaccine were imported to Armenia last March. Despite the spike in positive cases, suspicions of the COVID vaccines remain prevalent in the country.

Dr. Alicia Demirjian, an epidemiologist at Public Health England and a pediatric infection doctor at Evelina London Children’s Hospital, talks to CIVILNET’s Ani Paitjan to debunk the myths related to the vaccines.

Ani Paitjan: Can you please start by telling us the importance of vaccines?

Dr. Alicia Demirjian: Vaccines are not a cure. They are not a medicine to cure the virus. When people get the virus, the vaccine prevents them from becoming very unwell with COVID-19.

That prevents, probably, a lot of people from developing symptoms from COVID-19 if they are infected with it. But most importantly it prevents people from being hospitalized and from death. So, thousands of deaths have been prevented now thanks to the use of these vaccines.

As a collateral effect, it also appears that these vaccines are reducing the transmission rate so that if you had had the vaccine, it is less likely for you to pass the virus on to other people.

A.P: There is a ranking of the most effective vaccines against COVID-19 on the market. According to the efficacy rates, Moderna, Pfizer and Sputnik V are at the top with more than 90% efficacy, while AstraZeneca shows 67% efficacy. What should we make of these numbers?

A.D: First, we need to clarify the wording about effectiveness and efficacy that people sometimes use. When scientists do trials to look into vaccines, what they do is look at a group of people who received a vaccine and another group that did not. The latter is called the control group. Then, they look at the differences these people experience over time in terms of infections, hospitalizations and other outcomes. When this is all done in a clinical trial setting, this is called the efficacy.

And when we translate this into the real world and real situations, it is called the effectiveness. So this is when people are living their everyday life without knowing that there is an experiment occuring. They don’t know if they are in the vaccine group or in the control group, that is called the effectiveness, that’s the real world. Basically, without using difficult words, we can just say that the vaccines that are approved by some of the regulators, such as the Medicines and Healthcare Products Regulatory Agency, the U.S. Food and Drug Administration, the European Medicines Agency, are very safe and they work well. So their efficacy and effectiveness rates have been merged and are therefore high. These vaccines work very well to prevent severe infections with COVID.

What we have found in those trials is that they prevent severe illness with COVID, they also prevent hospitalizations and deaths. Meaning that if you are appropriately vaccinated, you have a lower risk of developing symptoms because, but also much lower chance of going to hospital or dying of COVID.

A.P: There is an ongoing controversy regarding the Oxford-AstraZeneca. The European Medicines Agency, which is the European Union’s medicines regulator, found a possible link between the AstraZeneca vaccine and rare cases of blood clots. Would you say that the cases are enough evidence to conclude that this vaccine is dangerous and should be halted?

A.D: It is a medicine and like any other medicine, it has side effects. No medicine is 100% safe. There are things, for example paracetamol or panadol, that people take for pain. And these things can have very serious side effects in a very small proportion of the population. For most people, they are fine but that doesn’t mean they are 100% safe. The other thing to keep in mind is that the AstraZeneca vaccine is extremely safe and it has saved the lives of thousands of people. AstraZeneca does have its own set of side effects. The most common ones are those that are mild or moderate. Most commonly, people have pain at the injection site, you can have soreness in the arm if that’s where you got the injection, people also have headaches, muscle pain, they are having joint pains, fever. All these things have been reported and they usually happen in something like 1 out of 10 people who received the vaccine. The symptoms go away on their own after a few days. Most vaccines have actually very similar effects to this. The recent conversation in Europe was about these extremely rare side effects related to blood clots that can be very dangerous.

First, it is very good news that the side effects could be seen, so that means there is a very good system in place to detect things that might be going wrong in case we need to slow down or even stop the distribution of the vaccines. And we need to continue doing that.

The second thing is that the number of cases due to side effects was extremely small. So, we are talking about something like a few cases over a million people who received the vaccine.

You have to compare it to the risk of not having the vaccine, meaning that you might be exposed to the novel coronavirus in your community. And the risk of that, especially in Armenia, as we know the numbers are not very good at the moment, is quite risky and we will have more problems if we are exposed to the virus.

A.P: Besides the cases of blood clots related to AstraZeneca, people seem to be hesitant about getting any vaccine injection. They are suspicious about the very short time it took for pharmaceutical industries to produce these vaccines. Are their fears justified?

I think it is normal for people to be a little bit hesitant about things that are new. And I think that’s an absolutely healthy outlook and we shouldn’t be jumping into things that we don’t know, even if they are good for us. I think this is a different situation now and we’ve come a long way from about a year ago or so. So this is really the miracle of people putting their heads together, their energy together, the funding together to already have several very good and very safe vaccines on the market. So that’s a real testimony of what human beings can do when they work together and that’s really brilliant.

We need to say that the vaccines have been victims of their own success, because they have worked well in many other areas like polio or pneumonia, illnesses that people used to die from when they were either children or young people. This doesn’t happen anymore thanks to vaccines. So, because people don’t see this as often as before, they may not be aware of the risks that exist if we weren’t using vaccines. And that’s why we have to be very careful. Sometimes in communities where the trust towards the vaccine has been reduced, there are some preventable illnesses that have returned.

I would say again that we are extremely lucky to have several options for vaccines that work well and that are safe. Being vaccinated does not only protect you but also your loved ones and people in the community, and we rely on everyone to get out of this pandemic.