“Why is it necessary to wear a face mask, physical-distance and observe other protocols after being vaccinated for COVID-19?”
This is one of the common questions by persons who are hesitant about taking a COVID-19 vaccine, two versions of which have been offered to persons in St. Vincent and the Grenadines.
And, at a Ministry of Health press conference, on Tuesday, Dr Franklyn James, registrar, Community Health Services addressed this question as well as other issues related to vaccination.
“The issue is efficacy and effectiveness,” he said in response to a question, using two concepts that he had explained earlier in the press conference.
James said that while some persons have used the words “efficacy” and “effectiveness” interchangeably as it relates to vaccination, “in truth and in fact, they do not mean the same thing”.
“The efficacy of the vaccine is determined by the producers who administer the vaccine to a group of selected persons under specific, controlled and ideal conditions. So you will note that everybody who produces a vaccine tells you of the efficacy,” James explained.
“What we are most concerned about is the effectiveness. And the effectiveness is determined after the vaccine has been given or administered to a large amount of people in the general population with varying health status, including comorbidity. So that is what we are most interested in.”
James said there is no mathematical or computer model that can predict effectiveness before the fact.
“The vaccine has to be administered to a large population and then we do our analysis and we conclude as to what is the effectiveness. So effectiveness is really and after-the-fact determination,” he said.
Relating to why protocols are necessary even for persons who have been vaccinated, James said:
“We are not certain how long it will take after administering or receiving the vaccine to develop sufficient immunity. So we have to err on the side of caution. So until we have access to that data, that hard data, not just coming from our own local circumstances but from an international standpoint that after you have had two doses of X vaccine you will be immunised totally after a particular period, then up until that period, we still have to take precautions, basically.”
chronological proximity not necessarily causation
“In terms of local reaction, there might be pain and swelling to the area where the vaccine was administered,” he said.
Generally, persons may have low-grade fever, chills or shivers, tiredness and some headache, the doctor explained.
“Now, like with any other substances that are administered or incorporated into our bodies, there may be issues of allergic reaction. But severe allergic reactions with vaccines are generally rare.”
James said there has been some report of some persons having allergies or dying after taking a COVID-19 vaccine.
“But, in most of these cases, causation has not been established. It is important to note that chronological proximity of events does not generally, or do not necessarily, indicate causation. So because two things happened in close proximity in time, it doesn’t necessarily mean that one is the cause of two.”
He noted that some persons have proposed acquiring natural immunity within the population, through herd immunity, the process through which people contract the disease then develop natural immunity.
“Well, that is dangerous because the disease can cause serious complications and even death, especially in persons who are susceptible, persons with certain underlying medical conditions,” James said.
“So, it is better to be exposed to a small amount of the antigen in the vaccine which allows your body to develop immunity than to be exposed to the disease whose severity you have absolutely no control over.”
He pointed out that measles gives a 1:500 chance of death while the measles, mumps and rubella (MMR) vaccine has a 1:1 million chance of causing severe allergy.
“So you are better off getting the MMR vaccine than coming down with measles,” James said.
He said it is a myth that vaccines cause autism, adding that there has been no link between the substance thimerosal, a mercury-containing substance, and autism.
“As a matter of fact, this substance is no longer used in vaccines yet the incidences of autism in the world remain basically the same.”
James said there was an issue where a British doctor published some papers claiming that the MMR vaccine causes autism.
“He was later struck from the British medical register because it was found that he falsified the data. And anybody can look up the name ‘Dr. Andrew Wakefield’.”
James also responded to the question of whether there is any danger associated with an asymptomatic positive person who does not know that he or she has COVID-19 taking a vaccine for the illness.
“The only company I have seen who has put a precaution as to whether a person who has had the disease should take the vaccine is the Sputnik-V people,” James said.
“But it is not because it creates any problem but it is just a precaution. But, in most cases, taking the vaccine has not been seen to create any serious untoward problems,” he added.
Sputnik-V and Covishield (Indian) AstraZeneca are the two vaccines currently being administered in SVG.
What if someone has COVID-19?
He also responded to a question as to whether there is a risk to a person who is administered doses of different COVID-19 vaccines.
“So far, it seems that there are no risks in terms of mixing or giving one dose of one vaccine [and the other dose of another],” James said.
“As a matter of fact, there are studies now on the way where they have been administering doses from different producers to patients to see if the resultant immunity is going to be higher. I know, for example, AstraZeneca is trying to work out something with the Sputnik-V people and there are others who have been looking at that.”
He, however, said that it is highly unlikely that a person in SVG would be administered doses of different COVID-19 vaccines.
The card that a patient is given records the type of vaccine that is administered to them and the card must be presented when the second dose is administered.
James further pointed out that the two vaccines that have been administered in SVG have differences between the two doses.
“… the period between the first and the second dose of the Sputnik-5 is 21 days. The period we are using between the first dose of the AstraZeneca and the second is six weeks. We are using six weeks but it can be between four and 12 weeks.
“But I think that it is extremely remote for persons to inadvertently give one dose of one vaccine in the first dose to a person and give another vaccine in the second dose,” he said.