When we look at the safety and effectiveness of any vaccine, studies report the numbers in many different ways. Several years ago, I did a video on the flu vaccine (see video here) and how the studies reported its effectiveness.
If you watched that video, you saw how they used statistical mathematics to make the flu shot seem more effective.
These math calculations are the same thing we see with the Covid-19 vaccination. Let me explain more.
Many experts believe that to bring this COVID-19 pandemic to an end, a large portion of the world needs to be immune to the virus by receiving the required protection through vaccination. In the past couple of months, several research teams wrote studies to challenge how well the vaccines offer protection. As these vaccines trick the body into making the spike protein that causes the disease, the possible side effects may include fever, headache, fatigue, pain, diarrhea, weakness, and swelling or itchiness at the injection area.
Clinical trials and expert researchers are trying to learn more about these vaccines to keep the public informed as new evidence becomes available. So in this article, we will discuss how relative risk and absolute risk vary in showing the safety and effectiveness of a vaccine to help you make well-informed decisions.
Efficacy and Effectiveness
Efficacy refers to the relative risk reduction or RRR. In other words, how well does any treatment do its job. It is a ratio that compares the risk of someone in the control group relative to someone in the treatment group. The efficacy and effectiveness of each vaccine are measured by the rates of disease between the vaccinated people compared to those who are not vaccinated.
Controlled clinical testings and trials measure the vaccine’s efficacy. In contrast, the vaccine’s effectiveness can only be determined once these vaccines are FDA-approved and are given to the general public. Or in the case of the Covid-19 vaccine given emergency authorization use by the FDA.
The duration of immunity provided by these clinically tested vaccines varies by individual and the type of vaccine, but generally, lifelong immunity may not be possible. Therefore, one should consider the time or period when vulnerability to the disease is most prevalent. Your risk of contracting any disease is directly related to your immune system function. Knowing how to keep your immune system high is essential.
What were the outcomes of the clinical trials?
The clinical trial evidence suggests that fully vaccinated individuals are less likely to get sick or severely ill with COVID-19. Severe sickness is the outcome they studied in the vaccine trials.
However, it is also important to note that some people who received all recommended doses of a COVID-19 vaccine may still get sick because no vaccine is 100% effective to all individuals. They did not look at this outcome in the trials.
If you were to ask most people if the vaccine prevented you from contracting the disease, most people would say yes. Sadly, most people believe this vaccine prevents you from contracting Covid-19. This belief is not true.
Thus, according to the World Health Organization, one should assess COVID-19 vaccine effectiveness using observational study designs for an unbiased evaluation and laboratory-confirmed result.
Do you think our health experts will do an unbiased evaluation?
According to a study published by The Lancet, vaccine efficacy is reported as a relative risk reduction. RRR tells us how much a specific treatment reduces the risk of bad outcomes as a proportion to the rate of the control group who did not have the treatment.
Here is an example from an article on NCBI’s website of RRR- “The relative risk reduction of fever and rash in the group of the children on the intervention was 40 percent (1 – 0.6 = 0.4 or 40 percent).” In this example, the relative risk was 0.4, subtracted from 1, giving you the 40% relative risk reduction.
It is important to note that no treatment can be expected to produce the same outcome for every individual. This is due to several factors, such as genetics, lifestyle, or an existing chronic illness. Therefore, these relative risk reduction statistics are implemented to allow medical practitioners to understand the likelihood that the treatment will produce an unfavorable outcome. RRR can help explain to patients what effects can be expected.
Another useful tool to calculate the effectiveness of a vaccine and prevent the virus’s further spread is absolute risk reduction (ARR). It is referred to as the difference between the event rates in the two groups–the control group and the treatment group. The result tells medical experts how much risk of an adverse effect could happen. ARR helps them alleviate this from happening. While RRR helps determine the total number of participants who could benefit from the vaccine, ARR helps them see the difference between attack rates in the groups with and without the vaccine.
A comparison of the numbers among the two is needed to derive the overall effectiveness and absolute reductions of a vaccine to allow medical professionals to figure out exactly how many lives the vaccine will save. Furthermore, when choosing which type of vaccine to take, it is crucial to use the RRRs and the ARRs to compare the science-backed evidence and have a complete picture of the actual data.
Efficacy Data From The Clinical Trails
The vaccination datasets published by governments and health ministries worldwide were reported to have a relative risk reduction of 95% for Pfizer-BioNtech, 94% for the Moderna-NIH, 90% for the Gamaleya, 67% for the AstraZeneca-Oxford, and 67% for the Johnson and Johnson vaccines. Lancet Microbe has also pointed out that the absolute risk reductions in Pfizer, J&J, and Moderna COVID-19 vaccines are as follows: 0.84% for Pfizer, 1.2% for J&J, and 1.2% for Moderna.
Another article published on the website Wired talks about these differences in statistics. It might be an easier read than the research study.
What does that mean for you?
We know all medical treatments that use medications or vaccines have side effects. Taking a new vaccine with limited safety studies has inherent risks. You have to consider your overall health, age, and risk of contracting a severe cause of Covid-19 with the unknown potential long-term risks. We will dive into the safety of this shot later. The overall effectiveness for an individual from the trials, which the ARR represents, is about 1% with these vaccines.
However, using the currently available data may not be enough to answer all our general questions because of the difficulty in different study protocols, including study populations, primary end-points, types of placebo, duration of exposure, background risks of COVID-19 during the study, statistical methods for efficacy, and many more.
Safety of the Vaccines
A large portion of our population is still hesitant to be vaccinated because of the misguided information about vaccines. On the other hand, research data from large clinical trials from the FDA has shown that vaccines from Pfizer and Moderna were deemed to have good safety records. Remember, these clinical trials had a limited time to study any adverse outcomes.
However, after these vaccines were distributed to the general public, we can see some alarming numbers that have not been reported in the media.
The Covid-19 adverse effects data is easy to find on the Open Vaers website. As of May 14th, there have been 4,201 deaths associated with the Covid-19 vaccines. You can also research this yourself by going to Vaers website directly. Open Vaers takes the data from the Vaers website and simplifies it.
Known Adverse Events
The federal agencies received reports about a small number of women in the U.S. who developed a severe and rare type of blood clot a few weeks after getting the J&J vaccine. Although the number of reported severe problems in controlled clinical trials was relatively low, it is still crucial to know the difference between those who received the actual vaccine and those who received a placebo.
Furthermore, a statement from the CDC suggests that people suffering from severe allergies to certain foods, insects, latex, or other common allergens should take caution and discuss the vaccination with a medical expert who can evaluate and assess their risks before deciding to get vaccinated.
Pfizer’s press release about pregnant women
Pfizer also put out a statement the pregnant women should avoid exposure to the vaccine during pregnancy. They also stated in their press release that exposure could be the following-
- “A female family member or healthcare provider reports that she is pregnant after having been exposed to the study intervention (vaccine) by inhalation or skin contact.”
- “A male family member or healthcare provider who has been exposed to the study intervention (vaccine) by inhalation or skin contact then exposes his female partner prior to or around the time of conception.”
If a pregnant woman has exposure to the vaccine (study intervention), the risks to watch are as follows-
- ectopic pregnancy,
- spontaneous abortion,
- intrauterine fetal demise,
- neonatal death,
- or congenital anomaly.
It is also important to stay vigilant with the information found online. Make sure to verify the new information with reliable sources to help navigate these ever-changing times.
It would be best if you made an educated risk vs. benefits analysis for taking these vaccines. Only you know what choice is best for you.