Mirror, Mirror on the Wall, which Vaccine Is Best of All? How Johnson and Johnson Stacks Up to the Existing COVID Vaccines


Please note: Vermont Mom Contributing Writer, Mario Trabulsy, MD is a board-certified emergency physician with over 27 years of experience. She is also a renowned and award-winning educator at University of Vermont Larner College of Medicine, and University of Vermont College of Nursing and Health Sciences. Her recommendations and answers here are not intended to replace conversations with your own medical care provider. 

Finally!! Another option in the list of available COVID vaccines has been approved and is shipping which has opened up vaccines to more people in a shorter time frame than before. This is great news!

In Vermont, teachers, correctional employees, child care providers, and people with certain chronic health conditions- in addition to those over 65- are now eligible for vaccines, or soon will be, and that makes us all SO happy. (if it doesn’t make you happy or you are worried about getting the vaccine, please read my vaccine blog.)

State of Vermont COVID-19 Vaccine Eligibility Schedule
Photo from https://www.healthvermont.gov/covid-19/vaccine/getting-covid-19-vaccine

My summary: I feel strongly that everyone should get a COVID-19 vaccine as soon as one is offered to them.

But wait a minute? You are being offered the newer Johnson and Jonson vaccine? But you heard it’s only 66% effective while the Pfizer and Moderna vaccines are 95% effective? You might be feeling slighted. You might want to hold out for “the good stuff”… right?

Resist the urge, take the first vaccine offered, as soon as it is offered, and settle in to read why those numbers, although true, don’t really tell the whole story. So what is the whole story?

Older woman received COVID vaccineA lot of the “whole story” has to do with statistics based on how often a disease is found in a population. When there is a lower frequency of infection in a population, a vaccine will statistically look better than a vaccine that was studied in a population with a high frequency of infection. What does this mean for our currently available COVID vaccines? It means that comparing the two mRNA vaccines (Pfizer and Moderna), which were studied when the incidence of infection in the community was much lower, to the Johnson and Johnson vaccine, which was studied when the disease incidence was much higher is like trying to compare marathon times for a person running a marathon in regular conditions and a person running a marathon pulling a 1-ton truck. A comparison of times just isn’t fair to the truck puller.

The Johnson and Johnson vaccine has an unfair disadvantage when it is compared to the Pfizer and Moderna vaccines in terms of how effective it is because it was studied later in the pandemic when the case numbers were much higher. The Pfizer and Moderna mRNA COVID vaccines probably won’t have as high efficacy in this more densely infected population as they did in their initial studies.

Another part of the story about the effectiveness of the current vaccine options is COVID-19 variants.

You’ve probably heard about the South African, UK, and Brazillian COVID variants which are more infectious and seem less susceptible to being prevented by the vaccines. Well, when the Pfizer and Moderna mRNA vaccines were studied, these variants had not yet emerged, so the vaccine efficacy numbers were not dragged down by having these variants circulating in the population.

The Johnson and Johnson vaccine efficacy study was conducted after these variants began circulating and their study includes information that about vaccine efficacy in disease prevention for the different strains (the vaccine had 72% efficacy in the United States but 57% efficacy in South Africa where most (85%) patients with COVID had the South African strain). The effectiveness of the Johnson and Johnson vaccine against ALL strains of COVID is good when you understand the differences in the type of disease in the populations being studied.

While the mRNA vaccine manufacturers acknowledge that their COVID vaccines are less effective against these newer COVID variants than the original strain, we don’t have the actual numbers and don’t know how those numbers would affect their published 95% efficacy. We certainly do know the new variants would lower the overall efficacy number if the studies had been done when the variants were circulating.

Because the disease changed while the different vaccines were being studied, we can’t compare head to head how effective each vaccine is on COVID, as it exists today.

The best news, however, lies in the definition of the word “effective”.

What does a study determine to be “effective”? Well, the term effective in these studies meant how many people did not contract COVID.

“Effectiveness” did not measure anything to do with how sick the people that did contract the virus got.

The great news is that even though more people may get infected with COVID-19 after having the Johnson and Johnson vaccine, the vaccine offered 100% protection against death and hospitalization in the study and 86% protection against severe disease (in the US), and 82% (in South Africa).

This study included people who were elderly and those with other serious conditions that impacted their health and made them more susceptible to serious disease or death. In fact, if you look beyond the initial 28-day mark, newly published numbers are showing even better results. Johnson and Johnson just released an update at 56 days and the numbers are looking like they will be in the 90-95% range effective against severe disease. These numbers approach the published numbers of the mRNA vaccines which, as mentioned earlier, were studied at a time where it was easier for a vaccine to look good (lower numbers in the population and no variants.)


The other not-yet-approved in the United States vaccine candidates, such as Oxford, AstraZeneca, and Novavax, are showing similar improvements in death and hospitalization among trial participants to the Johnson and Johnson vaccine.

Additionally, initial data is showing that Johnson and Johnson vaccine recipients are less likely to spread the virus even if infected, thus further lowering the rate of infection in the community. The initial studies of the mRNA vaccines did not look at this, although we expect that data at some point from them.

Johnson and Johnson is also a single-dose vaccine (the other approved vaccines need 2 doses, spaced about a month apart) and vaccine outcomes were reported after 28 days. The Johnson and Johnson vaccine can be stored at normal refrigeration temperatures, so is easier to transport and distribute to vaccination sites in rural areas and doesn’t require special storage.

Interestingly, some physicians are also starting to find that many (about ⅓) of their patients with long-term impact from COVID infection feel better after getting vaccinated. We don’t yet have statistics on this, but it is a noticeable trend.

If we can get everyone vaccinated before the more infectious and resistant variants become widespread, we could potentially quiet virus transmission down to a simmer even as we begin lifting the rules and eliminating many of the difficult sacrifices we all have made in this past year. Additionally, that simmer will likely not include death or severe disease of vaccinated individuals due to COVID 19, and will likely not overwhelm our healthcare system. This will allow people with other, non-COVID illnesses to get better care for those illnesses.

In summary, don’t be choosy or hold out for the vaccine you think you want. Get the first vaccine offered to you as soon as it is offered, and help prevent the spread, death, and destruction this virus has caused. All of the available COVID vaccines are amazing and can help us return to some semblance of our lives before COVID. I know each and every one of us can agree that is a good goal!

In the meantime, continue masking, distancing, and hand washing. There is light at the end of the tunnel. Let’s try to get there alive!

Mirror, Mirror On the Wall, which Vaccine Is Best of All? How Johnson and Johnson Stacks Up to the Existing COVID Vaccines


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