This was affirmed by Dr. Pham Quang Thai, Deputy Head of the Infectious Disease Control Department under the National Institute of Hygiene and Epidemiology, in his recent article sent to Nhan Dan Online. The following is the full text of the article.
After seven days administering the first doses of the COVID-19 vaccine in Vietnam, there were many emotions involved: suspense, expectation and joy as well as the anxiety and pride of frontline medical workers. The practical experience of immunisation officials and concerned authorities show that many things need to be paid attention to and shared widely.
By the afternoon of March 14, more than 15,000 people had been vaccinated against COVID-19 with the AstraZeneca vaccine. As recommended by the company, the immune response was not out of the norm. More than 500 cases had common reactions such as pain at the injection site, high fever and cold. In the cases who were followed up upon, the rate seemed to be higher with 69% having a common symptom such as a fever of over 37.5C (36%) and pain at the injection site (56%). These are common post-vaccination symptoms for most vaccines, especially following COVID-19 vaccination. Most people were fine after receiving the usual pain relief and fever reducers. In many cases, this phenomenon went away the next morning, feeling like there had never been such discomfort. This is why the rate of response recorded in Vietnam is lower than across the world (the common trend being that a day after injection, if the condition is fine, the vaccinated persons are not required to report on what they have experienced unless there is active monitoring applied on them). However, with 13 cases of second-degree anaphylaxis and one third-degree case, all promptly treated and have recovered, we also need to learn from such experiences for a better overall vaccination procedure.
Unlike previous vaccines based on a mechanism of introducing antigens into the body for the body to recognise and produce antibodies, the COVID-19 vaccines have been successful thanks to the latest technology, letting the body produce antigens and from there producing antibodies in the form of "vector" and mRNA vaccines. The principle of the vaccine currently in use in Vietnam is to use a cold-causing virus (Adenovirus) as a vector to carry the genetic material of the SARS-CoV-2 virus causing COVID-19 to human cells. After vaccination, the Adenovirus will find the target cells and transfer the genetic material inside. The cell with this gene segment will actively produce a spike protein of the SARS-CoV-2 virus and from there the body will mobilise immune cells to identify, produce antibodies and destroy it. With this new technology, the immune response will be very strong and create strong antibodies, but the post-vaccination response will also be stronger, consuming more energy from the body and for those with allergies, this may make them more susceptible. This is the reason why many people are having symptoms like pain at the injection site, fever, chill, muscle aches and headaches. Less common symptoms, such as dizziness and nausea, are also common after vaccination. Some other less common symptoms such as diarrhoea and abdominal pain often come later, on the second day after injection.
Some have advocated a reversal: whether or not to stop injections? It is true that with no immunisations there will be no reaction, but there is therefore will also be no immunity given unlike many countries which are actively carrying out their immunisation campaigns to quickly achieve herd immunity. Vietnam cannot be an oasis in the world if we hesitate. So how do we inject safely? Who is safe for inoculation?
Firstly, it should be noted that, if someone has a history of a severe allergy to any vaccine ingredient, or was allergic to a previous dose, they will not be injected. Those with an underlying medical or allergic background need to be injected at the hospital under strict medical supervision. Without these issues, qualified adults can feel safe rolling up their sleeves.
Secondly, on the part of he or she who administers the vaccination, the emergency team is always ready with for anaphylaxis. This is the foundation for their colleagues to work firmly in delivering the vaccination. We have handled adverse events very well in the past and we will do well in the future as well. There is no drug or vaccine that is absolutely safe for everyone, but if administered, it will protect those vaccinated and the community in general from the COVID-19 pandemic.
According to the vaccination data to date as well as the actual experiences of health workers who have used the vaccine, the situation is quite positive. There have been cases of hypersensitivity, meanwhile there have also those who feel as if nothing has happened. There are still cases where inadequate information about allergy history is given to the doctor, and only when there is a problem can the situation be reversed for evaluation. The Ministry of Health will continue to make the necessary adjustments to make screening more thorough. And, remember, only those who are vaccinated can understand how they feel at their best, and when to arrive at a medical facility and provide early medical information to help facilitate the vaccination, as well as helping avoid adverse reactions. It is unknown if vaccinated people who may have the infection are asymptomatic and from there it will continue to spread, or whether or not the vaccine will protect against the most recent variants of the coronavirus. This should be strictly monitored in the next phase.
Around the world, there are also some countries that have suspended vaccination because there is some unfavourable information, but so far even the UK, where this vaccine was invented, local government has confirmed that there is no evidence of a causal relationship between any severe reaction and the vaccine. This is also the reason why the World Health Organisation has recommended the continuation of the vaccination. Reaction after injection is part of inoculation because it is the mechanism by which the body responds when it encounters a foreign object and by which we also have immunity. If we understand its nature, are willing to respond (and respond in a timely manner), there will be no interruption in vaccinations or any disruption of the efforts towards a true state of “new normal”, with international travel and economic exchange bustling as before. Vietnam has long been waiting for its first doses of COVID-19 vaccine, and so far, vaccines are still the best solution to overcome this crisis.
Dr. PHAM QUANG THAI, Deputy Head of the Department of Infectious Disease Control, National Institute of Hygiene and Epidemiology
