If you are like many people, you’ve probably been told by your health care provider that you should “know your numbers”. The “Know Your Numbers” campaign has been successful in teaching people to know their target numbers for such health markers as HbA1c, cholesterol, blood pressure and body weight.
Recently some other numbers have been making their way into the conversation, particularly around the COVID shots. Perhaps you have heard of The Number Needed To Vaccinate (NNVT). It’s very similar to the Number Needed to Treat (NNT), which I have talked about in my blog Why I Won’t Take These ‘Safe’ Drugs.
The NNTV for the COVID-19 shots refers to how many people need to be injected in order to prevent one 1 case of COVID-19 or prevent 1 COVID-19 related fatality. The NNTV is nothing new. However, unlike the NNT, which is balanced by the Number Needed to Harm (NNH) during the drug review process, the NNTV for the COVID-19 shots is being discussed in a vacuum without considering how many people may be harmed in order to prevent 1 person from contracting COVID-19.
Ideally the NNT for any drug would be 1. In other words, only 1 person would need to be treated for 1 person to achieve benefits. However, this is almost never the case. (The ideal NNH would be 0. Again, this is almost never the case. You can learn more about NNT at TheNNT.com, which has a database of therapies/NNT reviews). So, scientists do a lot of calculating to determine exactly how many people need to take a drug (and how many will be harmed) for it to be effective for 1 person.
This is also true for vaccines. The NNTV ideally would be 1. In other words, you would only need to vaccinate 1 person to prevent 1 person from contracting a disease. But math can be tricky. Especially the math researchers use to determine how well a vaccine works, and what risks are associated with it. Recently, many in the medical field have expressed differing opinions regarding the safety and efficacy of the coronavirus shots, specifically the mRNA versions. As such, there is currently a wide range of NNTV figures being used to back up vaccine efficacy claims.
For example, the NNTV number that has been widely repeated for the Pfizer shots is 142; for Moderna it is 88. What does this mean? Well, if these numbers are accurate, it means that 142 people would need to be injected with the Pfizer shots or 88 people would need to be injected with the Moderna shots for 1 person to avoid infection from COVID-19. The experts calling for everyone to get the shots believe these numbers support the narrative that the vaccines are effective.
However, the authors of a June, 2021 article titled The Safety of COVID-19 Vaccinations—We Should Rethink the Policy, used the data from a large Israeli field study and two adverse drug reactions databases (the European Medicines Agency [EMA] and the Dutch National Register) to analize the purported Pfizer and Moderna NNTVs. They determined that to prevent just 1 COVID-19 case using the Pfizer shots, the NNTV would need to be between 200-700, and to prevent 1 COVID-19 fatality the NNTV would need to be between 9,000-50,000!
A March 2021 study, which looked at the NNTV to prevent one COVID-19-related death in 1 year showed that NNTVs were more favorable in sick, elderly populations needing surgery—specifically, people over 70 years old needing cancer surgery. In that 70-year-old plus cancer population the NNTV varied widely between 197-816. In other words, up to 816 people would need to be vaccinated to prevent one elderly cancer patient in need of surgery from COVID-19 death. For non-cancer surgery patients, the NNTV was even higher between 407-1,664 meaning up to 1,664 people would need to be vaccinated to prevent 1 COVID-19 death in this elderly surgical population. Finally, in the general population (all age groups) the study found that the NNTV was the highest—between 1,196-3,066! That means 3,066 people need to get the experimental shots to prevent 1 person from COVID-19 death.
So, here is the dilemma. To do a benefits-harm analysis you first need to know if the NNTV is 88, or 200, or 3,000, or 50,000. And remember, the NNTV does not tell you how many people would be harmed.
Absolute Risk Reduction versus Relative Risk Reduction
Other numbers are also important in your analysis. In a February 2021 appraisal of clinical trial data titled Outcome Reporting Bias in COVID-19 mRNA Vaccine Clinical Trials author Ronald B. Brown points out that Pfizer and Moderna never reported on the Absolute Risk Reduction (ARR) in their phase III clinical trial data—an FDA requirement! Absolute Risk Reduction (ARR) is the disease risk difference between the placebo and vaccine groups, in other words, ARR is the equivalent of vaccine risk reduction relative to placebo risk. ARR is also known as the vaccine disease preventable incidence (VDPI).
So, what did Pfizer and Moderna report on in their phase iii clinical trials data? They reported on something called Relative Risk Reduction (RRR) which is the reduced risk from vaccination, often referred to as “vaccine efficacy.” Semantics are tricky.
According to Brown who has published numerous scientific articles and reviews,
Reporting relative measures may be sufficient to summarize evidence of a study for comparisons with other studies, but absolute measures are also necessary for applying study findings to specific clinical or public health circumstances. Omitting absolute risk reduction findings in public health and clinical reports of vaccine efficacy is an example of outcome reporting bias, which ignores unfavorable outcomes and misleads the public’s impression and scientific understanding of a treatment’s efficacy and benefits. Furthermore, the ethical and legal obligation of informed consent requires that patients are educated about the risks and benefits of a healthcare procedure or intervention.
In a rapid response to the editor of The British Medical Journal published in January 2021, pediatrician Allan S. Cunningham, M.D. wrote:
Pfizer’s vaccine “may be more than 90% effective”, (Mahase, BMJ 2020;371:m4347, November 9). Specific data are not given but it is easy enough to approximate the numbers involved based on the 94 cases in a trial that has enrolled about 40,000 subjects: 8 cases in a vaccine group of 20,000 and 86 cases in a placebo group of 20,000. This yields a Covid-19 attack rate of 0.0004 in the vaccine group and 0.0043 in the placebo group. Relative risk (RR) for vaccination = 0.093, which translates into a “vaccine effectiveness” of 90.7% [100(1-0.093)]. This sounds impressive, but the absolute risk reduction for an individual is only about 0.4% (0.0043-0.0004=0.0039). The Number Needed To Vaccinate (NNTV) = 256 (1/0.0039), which means that to prevent just 1 Covid-19 case 256 individuals must get the vaccine; the other 255 individuals derive no benefit, but are subject to vaccine adverse effects, whatever they may be and whenever we learn about them.
Dr. Cunningham also wrote:
Moderna’s phase III trial has shown that, so far, the vaccine is 94.5% effective, (Mahase, BMJ 2020;371:m4471, November 17). As with the Pfizer vaccine news release, few numbers are provided, but we can approximate the absolute risk reduction for a vaccinated individual and the Number Needed To Vaccinate (NNTV): There were 90 cases of Covid-19 illness in a placebo group of 15,000 (0.006) and 5 cases in a vaccine group of 15,000 (0.00033). This yields an absolute risk reduction of 0.00567 and NNTV = 176 (1/0.00567). There were 11 severe illnesses, all in the placebo group, for an absolute risk reduction of 0.00073 and NNTV = 1,370. So, to prevent one severe illness 1,370 individuals must be vaccinated. The other 1,369 individuals are not saved from a severe illness, but are subject to vaccine adverse effects, whatever they may be and whenever we learn about them.
As Dr. Cunningham shows the Absolute Risk Reduction measures tell a very different story regarding NNTV than the Relative Risk Reduction measures do. Yet, both Pfizer and Moderna failed to report required ARR measures in publicly released documents. In addition, U.S. FDA Advisory Committee (VRBPAC) did not follow FDA published guidelines for communicating risks and benefits to the public. Finally, the committee failed to report ARR measures in authorizing the Pfizer and Moderna vaccines for emergency use.
The math is complex, but the reason for reporting the trial data this way is simple: By reporting only Relative Risk Reduction, Pfizer and Moderna can say that the shots are “95% effective.” The medical journals that reported the phase iii clinical trial findings with no mention of ARR measures being excluded has the effect of misleading doctors who read the journals and ultimately the general public with regard to vaccine efficacy. This most certainly breaches ethical and legal requirements related to informed consent.
And there is more tricky math.
How Many People Really Need to Be Vaccinated?
As you can see, the NNTV figures being reported are not as straightforward as they seem. For one thing, adverse events are not being included and these must be considered so people can fully determine the benefits versus risks.
Using the May 2021 numbers as reported on the VAERS database, it’s easy to see that the full story is not being shared with the public. As of May 14, 2021 the number of “serious” adverse events recorded in the VAERS database was roughly 180,000. Please note this number only represents recorded “serious” adverse events. The total number of recorded adverse events was 270,000, and recorded deaths were 4,201. And these are just the numbers recorded in the VAERS database. The actual number of reported adverse events and deaths are assumed to be even higher, but only those “proven” to be related to the vaccine get recorded. Also remember that only about 1%-10% of adverse events get reported.
In his article The Mathematical Conundrum of a Modern Medical Miracle Cure, authorJan Wellman uses Pfizer’s original statement of “95% effective” based on the RRR and extrapolates. He says that, using the numbers reported in The Lancet the Pfizer ARR rate after Phase 3 trials was 0.98%. This means that NNTV with the Pfizer shots to prevent 1 COVID-19 case is 117 (NNTV = 1/ARR). Although using the Israeli data the ARR for Pfizer is closer to 0.46%, so the NNTV is 217.
He then goes on to include Infection Fatality Rate (IFR). IFR is the number of people who need to be infected to produce 1 fatality. Using an IFR of 0.05% for people under 70 as reported by PANDATA.org, Wellman states that 2,000 people would need to be infected by the virus to produce one fatality. He concludes that to avoid one COVID-19 death, the NNTV is 434,000 (217 x 2,000).
Wellman doesn’t stop there. With 155,251,852 million vaccinated in the U.S. and 179,176 “serious” adverse events and 4,201 dead in the USA, he extrapolates further to determine how many people would need to die or be seriously harmed to prevent 1 COVID-19 fatality. The numbers are sobering. He concludes that 12 people would need to die and another 502 would need to be seriously harmed to prevent 1 COVID-19 fatality.
In summary Wellman shows that 434,000 people would need to be vaccinated; of them 12 would need to die and 502 would need to suffer serious injury to prevent just 1 single COVID-19 fatality.
In his Moderna rapid response letter Dr. Cunningham provides some additional perspective:
How does this (NNTV=1,370) compare with other vaccines? Before the measles vaccine became available 90% of children in North America had measles by age 10. Two doses of the vaccine are about 95% effective, so a vaccinated individual’s risk is reduced by 0.855 (0.90 x 0.95), and the NNTV = 1.17 (1/0.855); this is extraordinarily effective…Shouldn’t absolute risk reduction be reported so individuals can make fully informed decisions about vaccinations?
What do you think of NNTV? Do you consider NNT/NNH or NNTV when making personal medical decisions? Do you think the numbers tell the full story?