Many of you have already had your first dose of the Moderna or the Pfizer vaccine, or your single required dose of the Johnson and Johnson vaccine against the SARS-CoV-2, the novel coronavirus.
All states should have active vaccination campaigns in full swing, targeting front-line health professionals and the most vulnerable groups of people first. Thanks to the new administration, the number of shots going into arms has doubled in just a few weeks and the goal is to have all Americans vaccinated by the end of May 2021.
But you may be shocked to hear of cases where individuals received the vaccine, yet still tested positive for the coronavirus, with or without symptoms.
How is that possible? There are a couple of explanations.
It should first be pointed out that no vaccine is 100% effective. The annual flu vaccine is about 50-60% effective. In some folk, the vaccine just may not work well.
This could be a result of how the person’s immune system handles the vaccine, whether the dose is adequate or if there are complications from some underlying medical condition.
But these vaccines against COVID-19 are highly effective (up to 95% for the two-dose vaccines) so why are some people testing positive?
The answers are pretty simple: vaccines take time to work. First, it’s important to understand that Moderna and Pfizer vaccines provide maximal protection after TWO vaccinations. The 95% protection for these vaccines in the studies was observed after both of the vaccinations were received. For example, with the Moderna vaccine, the maximum response from the first vaccination occurs around 4 weeks.
This is when the second vaccination is given and that response requires another week before it is maximal. So it is when vaccinated subjects have reached this point that the protection is highest. For a single-dose vaccine like the Johnson and Johnson vaccine, it also takes a few weeks before maximal protection is achieved.
Therefore, it is totally understandable that someone could get vaccinated and then be exposed to the coronavirus before the level of immune protection is great enough to halt the infection.
This is why it is extremely important that you follow all social distancing guidelines and mask-wearing until at least a week after completing both vaccinations or 4 weeks after a single dose vaccination!
Another possibility is that a person could already be infected before they get their vaccination but just not experiencing symptoms.
This can occur because no type of COVID-19 tests are required prior to getting the vaccine.
It should be noted, at least in clinical studies, people who got infected after being vaccinated generally did not require hospitalization, and none of them died. So the vaccine still provided an important benefit.
The question of how well these vaccines will protect us against the new mutant strains of the virus remains to be answered but scientists are working extremely hard to answer this critical question.
Stay tuned; new information is continuously coming in.