The Numbers You Need to Know Now

by Christiane Northrup, M.D.

Medical Insights & News Women's Health

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, 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:

Dear Editor,

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, 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?

Last Updated: July 20, 2021

Christiane Northrup, M.D.

Christiane Northrup, M.D., is a visionary pioneer and a leading authority in the field of women’s health and wellness. Recognizing the unity of body, mind, and spirit, she empowers women to trust their inner wisdom, their connection with Source, and their ability to truly flourish.


Add comment
  1. Donna J. Cole
    1 year ago

    Dr Northrup, my name is Donna J Cole, I am a retired LPN and this year DID NOT renew my License, due to all the knowledge that I have obtained on the hoax of this mRNA bioweapon shot…..I just listened to You with M. Jaco, & SG Anon… all of you, Clay Clark, Mel K, Dr Tenpenny, Dr Malkovich, etc….I knew mRNA was a bioweapon when all of the world was shut down back in 2020…..I worked in Nursing for 25-yrs started as a Nurse Aide at age 15 yo, on to LPN school after a divorce with two sons, then to another career…my question… what do you feel about BONE DENSITY tests, I am due on the 9th of March-2023…..DX with Invasive Lobular RIGHT BREAST CANCER in 2018, two lumpectomies.. my 5th year hoping to be free this year, refused all radiation, and hormone blockers….this type not curable using chemo, told by my Oncologist……I hate the system of tests in the medical field, I do every 6-month follow ups with blood draws and mammograms yearly, my Dr believes in the covid narrative, masks on office calls……my yearly physicals are a joke….they say at age 75 it is non touch, I live in Michigan with controlled medical systems. I will turn 76 soon…..thanks for your time, need advice on Bone density testing

  2. Marlene Britt
    3 years ago

    Could you recommend a women doctor in San Diego. My daughter needs to have her hormones tested. Thank you. Marlene Britt.

  3. marianna
    3 years ago

    Thank you Dr. Northrup for your courage to stand up against all the lies and misinformation. You have been instrumental in many of my health decisions over many years. So many women feel shamed for following their inner wisdom and especially now when our loved ones, colleagues and friends have bought the narrative and are trying to force us to think like them and drink the Koolaid. We all have to have the inner strength to listen to that small voice inside that tells us what is best for us and not just go along to make everyone happy.

  4. Shelley
    3 years ago

    Please would you consider sharing our in-house video to your like minded friends/network in anticipation of children returning to school in Autumn …

    Please share this take on a Pink Floyd Cover. It includes an Informative Video featuring many articles and like minded individuals that I have found invaluable over the last two years. All here in one place, some websites, all their names and many posts, etc, for you to look at, search out, see and hear. Photos of the July UK Trafalgar Square Freedom March with video footage of crowd singing along to this anthem. Produced in an effort to help end the program and one way narrative being rolled out all over the world, which is now concentrating on children and pregnant women. As a Musician, it’s my way of shining light and, to everyone working toward this… Love & Peace! Andy x

  5. Rebecca
    3 years ago

    Dr. Northrop, thank you for being a warrior for the truth. Those of us that opened our eyes by following you and many, many other Doctors and scientist not bought off by Big Pharma, Big Tech, or Big Business have watched in horror as so many failed to do their own research and believed blindly what they were told. Now we have all the deaths caused by this nasty needle to show. As you know, 12 year olds don’t die of myocarditis normally. There will always be the evil ones, and the new-sayers but you have put your heart and soul into educating those looking for the real science. God Bless You and I hope to see you at the Awake America Tour!

  6. Jean S.
    3 years ago

    Dr. Northrup, brilliant article! You covered all the bases. Too bad so many people we suckers into getting this vaccine. What they don’t know is this is no vaccine. Look at how many people are getting covid AFTER taking this “vaccine”. The truth is coming……there is no way there was 600,000 deaths in this country from covid. That is yet another huge lie from the main stream media. You will hear me celebrate when the media gets arrested! Anyone who cannot see that the prison fence around the Nations Capital is to keep all of the criminals in there while our military conducts their tribunals is in for a huge surprise. Can’t wait tell this country finds out about all the arrests being made of all the politicians who have committed treason which is most of them. Oh happy day! Justice is coming and Big Harma will be arrested to for Crimes Against Humanity for all those who have died from the “vaccine”. Thank you so much for being brave to speak 100% truth! You rock!

  7. Jan
    3 years ago

    OMG, Do you think that we don’t all have eyes. The death rate has dropped dramatically since the vaccine has taken hold. The death rates are up where there have NOT been vaccinations. What more proof does one need? Yes there are always those instances where there will be adverse reactions. It is unfortunate and the reason we all should weigh this carefully. There have been over 600,000 deaths in the US but the fact is that they are going down based on the vaccine. I know that you will say, this probably would have happened because of herd immunity but you are wrong. I live with polio because I was in the last years of the epidemic before the vaccine came out. I wish to god that I had the vaccine before that happened to me.
    I used to think that everything you spoke about I could trust but in this area we are at polar opposites. Science has shown us that unless we stop this, it will keep mutating. It’s the mutations along with misinformation that we all should fear the most.

    1. Cherie
      3 years ago

      Your brainwashed and misinformed. You can’t rely on misconstrued data and censoring to draw an honest conclusion. You really have to open your eyes to the corruption and the power hungry Globalist who want nothing more than to control the masses! This Plandemic is truly EVIL! Wake up!!!

    2. Jean S.
      3 years ago

      Jan, it is people like you who are brainwashed into believing all the lies being fed that are marching us straight into communism. Look at the poor Chinese people who have worn masks for years as a form of suppression. They do live with vaccine passports and are tracked that way. If they refuse to wear the mask, get yet another poisonous “vaccine” it is reflected in their “score”. They are then denied entrance to food markets, shopping, etc. Do you want to live like that? You mention “facts” and “science” but what you don’t understand that this entire covid “Plandemic” was 200% planned and designed to take down our country and usher us quickly into communism and socialism. Rest assured the real truth is coming. I am truly sad to tell you this but it was not the covid “virus” that was supposed to take us out… is the vaccine. There have been over 4,000 deaths from this “vaccine” not to mention the thousands of people that had blood clots, heart attacks, strokes, etc. after having this “vaccine”. The truth is being suppressed by main stream media which includes the press and social media. Thank you God that justice is coming. I pray everyday that all that got the vaccine survive it. It was actually designed to take people out at about the 2 year mark upon them receiving it. If all died right away no one would take it. Pray for those who have taken this. Huge crimes against humanity!

  8. Vicki SM
    3 years ago

    I love your articles and the fact you are always bringing truth and support into the medical and health equation. I am not scientific nor medically trained and don’t base my decision not to vaccinate on NNT’s but on other interesting facts I have read. Is it actually a vaccine? Does it produce antibodies? Isn’t that what vaccines are supposed to do? I remember thalidomide and it had a similar short testing span. Did we not learn from that? Isn’t it taught in Medical school not to vaccinate during a pandemic? Why are Drs not reporting so many deaths and adverse reactions (did you see Eric Clapton’s statement?) Why aren’t we being offered Ivermectin or hydroxychloroquine when they have been known to be relatively safe and effective for a long time? Why is Big Pharma not being punished for offering false or misleading stats? And why are they not accountable for adverse side effects from their medicines/vaccines. What’s happened to the Vit D trials and evidence of that potentially saving lives with NO adverse side effects. What else can we do to keep the movement alive to advise the public of these facts? Thanks for doing your part Goddess Christiane.

  9. Friday
    3 years ago

    You write very good articles about Covid, however what are you doing involved with “The reawaken America tour” which associates you with such despicable
    traitorous criminals as Michael Flynn and Roger stone?! What do they know about health anyway??

    1. Cherie
      3 years ago

      Your misinformed, brainwashed and stupid! Go move to China where you’ll fit right in! Stop believing lies!!!

  10. MaryPat
    3 years ago

    Thank you for sharing and explaining these numbers. People should know this information. Now, what do we do with this information when the entire world in talking in another reality? These days I often feel that I am in an alternate universe.

    1. Cherie
      3 years ago

      Your not alone. There are very Evil doers out there in too many positions of power who are weak minded and guilt ridden fools! Especially among those in the Elitist group who have overstepped their boundaries! Their lack of common sense and pure EVIL has allowed MANY OF THOSE psychopathic liars to seep into places where it does not belong, no thanks to double standards and LAWFARE. Their beliefs are hate driven and they believe the ideology/ idiotology because they’re narcissists and that has spread like cancer!

  11. Becca
    3 years ago

    Thank you for this information. First of all, I want to tell Dr. Northrup that she changed my life. I had been on synthetic hormones when I was very young, my early 20s, because of premature menopause. The side effects were awful. No doctor mentioned anything at that time about bioidentical hormones. Synthetic was all they prescribed. I had to do my own research, which led me to Dr. Northrups work, and take that knowledge to a Dr. who prescribed them. I’ve been balanced hormonally ever since. I’m 60 now and taking the lowest possible dose, but still feel great. The COVID Vaccine has caused me so much anxiety. Because of my experience with hormones, pharmaceuticals, and doctors not always knowing what’s best, I’ve decided to listen more to my intuition rather than the media. My body and intuition is telling me not to take it at this time. However, there is so much pressure from media and public that it if you don’t, your life is at risk. I am a teacher going back to school in the fall. Most of the teachers were vaccinated and a handful chose not to. I know that I am going to face people judging me about my decision, thinking it was an irresponsible and selfish act not to get the vaccine. I am having trouble relaxing this summer because I am going back and forth about getting it in time to go back to school. My family has already told me that I am selfish. However, every time I go to sign up for the shot, something, like this article, guides me back to my inner voice telling me not to do it.

  12. susan wright
    3 years ago

    I find the math a little confusing, although, your explanation makes sense, thank you.
    I am unvaccinated, not because I’m anti -vaccines, but because I have a mistrust in the CDC, big pharma & tricky math. I continue to mask, social distance & use good hand washing.
    I don’t know if I’m doing the right thing, but I truly hope so.

  13. Gloria
    3 years ago

    Very helpful information – thank you for sharing.

    I am currently wondering how my unvaccinated status is cause for the virus to mutate and potentially harm others. That is an argument I heard on the radio this morning. Don’t viruses mutate on their own regardless? How am I responsible for this?

    Thank you!

  14. Catherine
    3 years ago

    Hi Christiane, thank you so much for such an excellent article. Thank you for doing us the immense service of putting together a rational, factual, referenced article with precise numbers, in a way that is understandable to non experts. How are normal people supposed to make sense of the media messages we are bombarded with on such a technical subject without support from Doctors like yourself? I was aware and able to explain conceptually that the trial designs enrolled a huge number of people to stop after a tiny number of Covid cases and then took a favourable calculation without considering AEs so newspapers could announce 95% efficacy. I had heard the numbers explained in spoken interviews but not as clearly as above. I have been asked for a specific numerical example so many times. I am very grateful and will share from now on every time I am asked for numbers. PS Dr Alan Cunningham is displaying clear star quality! When can we hear him on the interview circuit?

  15. Hannah Williams
    3 years ago

    Thank you so much for sharing valuable information. There are so few people who are willing to take a stand for humanity and provide well rounded data so that we can make informed decisions about our health and wellness. Knowing the full spectrum of benefits and risks is essential. It’s infuriating that important information is being kept from the public to support a narrative. How is that legal?! Thank you for all you are doing!

    1. Hannah Williams
      3 years ago

      Please excuse my typos! Typing with thumbs way too early on a phone….

  16. Julie
    3 years ago

    Hi there
    I used to watch the dailies on instagram and miss them! We have some serious shit happening here in UK as I know you do too. Censorship is huge and on so called ‘freedom day’ two days ago Boris said on a live broadcast that vaccine Id passports would be implemented come september. This goes along with everything that has come up for me this last 18 months. I have a 9 year old daughter who will be vaccinated over my dead body, but like many I can see where this is going. What other platforms can you be found on?
    Many thanks
    Julie Howe

    1. Coulson Duerksen
      3 years ago

      Hi Julie,

      Be sure to sign up for Dr. Northrup’s eNewsletter if you do not already receive. And look for her on MeWe,Telegram and soon on Rumble.


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